Journal of Human Hypertension (2015), 1–8 © 2015 Macmillan Publishers Limited All rights reserved 0950-9240/15 www.nature.com/jhh
ORIGINAL ARTICLE
Factors associated with hypertension prevalence, awareness, treatment and control among participants in the International Mobility in Aging Study (IMIAS) B Doulougou1,2, F Gomez3, B Alvarado4, RO Guerra5, A Ylli6, J Guralnik7 and MV Zunzunegui1 The aim of this study is to assess the factors associated with hypertension prevalence, awareness, treatment, and control, in the elderly populations of the International Mobility in Aging Study (IMIAS). Approximately 200 men and 200 women aged 65–74 years were recruited at each site (n = 1995) during IMIAS’ 2012 baseline survey at five cities: Kingston (Canada), Saint-Hyacinthe (Canada), Tirana (Albania), Manizales (Colombia) and Natal (Brazil). Blood pressure and anthropometric measurements were taken at participants’ homes. Hypertension prevalence ranged from 53.4% in Saint-Hyacinthe to 83.5% in Tirana. Diabetes and obesity were identified as risk factors in all cities. More than two-thirds of hypertensive participants were aware of their condition (from 67.3% in Saint-Hyacinthe to 85.4% in Tirana); women were more aware than men. Awareness was positively associated with diabetes in Kingston, Manizales and Natal. Though most of those aware of their hypertensive condition were being treated pharmacologically, associations between awareness and physical activity and refraining from smoking were weak. Control among treated hypertensive participants was low, especially in Tirana and Natal. Diabetes and physical inactivity were associated with poor hypertension control. Hypertension is common in the older populations of IMIAS. Diabetes is strongly associated with hypertension prevalence, awareness and lack of control of hypertension. The fact that awareness is not strongly associated with healthy behaviours suggests that antihypertensive medication is not accompanied by non-pharmacological therapies. Improved health behaviours could strengthen hypertension control. Efforts should be made to increase men’s awareness of hypertension. Hypertension control in diabetic patients is a challenge. Journal of Human Hypertension advance online publication, 2 April 2015; doi:10.1038/jhh.2015.30 INTRODUCTION Non-communicable diseases constitute a serious threat to population health and human development. A recommendation has been made to embed them in the post 2015 development agenda.1 The foremost group of these diseases is cardiovascular disease, which in 2008 caused 48% of global deaths due to non-communicable diseases.2 Hypertension is the leading modifiable risk factor for cardiovascular diseases3 and was the first leading risk factors for global disease burden in 2010.4 In 2000, 26% of the global adult population had hypertension and the number of hypertensive adults was predicted to increase to about 60% by 2025.5 Yet hypertension is a readily treatable risk factor for the most common causes of morbidity and mortality in older age (stroke, ischaemic heart disease, renal insufficiency, Alzheimer’s disease).6,7 The co-existence of diabetes and hypertension confers an enhanced risk of cardiovascular diseases.8–10 Hypertension prevalence increases with age. According to the World Health Organization trends, the number of people aged 65 years and older is projected to grow from an estimated 524 million in 2010 to nearly 1.5 billion in 2050, with the greatest increases in developing countries.11 So particular attention should be given to elderly populations at a risk of hypertension in those countries.
A recent study on hypertension among older adults in six low- and middle-income countries showed that hypertension prevalence was comparable to that of developed countries and that awareness was low.12 Knowledge about factors associated with hypertension prevalence, awareness and control among older adults in different regions of the world will contribute to global prevention and management of this chronic disease. The International Mobility in Aging Study (IMIAS) gives us an opportunity to examine hypertension problems among five distinct older adult urban populations from four countries with very different histories and healthcare systems—one high-income (Canada) and three middle-income (Brazil, Colombia and Albania). Many studies have been published on the prevalence of hypertension among adult populations across the world, but relatively little is known about hypertension issues specifically among older adults. In Canada, studies have examined prevalence, awareness, and control in populations 20 years of age and older but did not examine associated factors.13–15 Statistics Canada reports on the prevalence of self-reported hypertension, which was ~ 45% among persons aged 65–74 years in 2013.16 According to the 2007–2009 Canadian Health Measures Survey, hypertension prevalence for the 60–79 years old group was 53%, awareness was 86%, pharmacological treatment was received by 85% and control
1 École de Santé Publique de l’Université de Montréal (ESPUM), Montréal, Quebec, Canada; 2Département biomédical et santé publique, Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso; 3Research Group on Gerontology and Geriatrics, University of Caldas, Manizales, Colombia; 4Department of Public Health Sciences, Queen’s University, Kingston, Ontario, Canada; 5Department of Physiotherapy, Universidade Federal do Rio Grande do Norte, Natal, Brazil; 6National Institute of Public Health, Tirana, Albania and 7Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, Baltimore, MD, USA. Correspondence: B Doulougou, Département de Médecine Sociale et Préventive, École de Santé Publique, Université de Montréal, 850 Rue Saint Denis, 3ème étage, Bureau S03-806, Montréal, Quebec, Canada H2X 0A9. E-mail: [email protected] Received 15 January 2015; revised 23 February 2015; accepted 27 February 2015
Factors associated with hypertension in IMIAS participants B Doulougou et al
2
reached in 66% of those treated.14 Gaps in knowledge have been noted in recent studies of hypertension in Albania17 and Colombia.18 In Brazil, some studies have included older adult populations, but they are either limited to self-reported hypertension and do not report on treatment and control19–21 or else concern broader populations aged 18 years and over, with results published on the entire sample.22 Such studies do not provide specific knowledge regarding the burden of hypertension on elderly populations. Our aim was to assess the factors associated with hypertension prevalence, awareness, treatment and control in the elderly populations of the IMIAS study. METHODS The IMIAS study The IMIAS is a prospective cohort study conducted in five locations: Kingston (Ontario, Canada), Saint-Hyacinthe (Quebec, Canada), Tirana (Albania), Manizales (Colombia) and Natal (Brazil). Standardized training was given to all investigators and all documents were made available in all relevant languages (English, French, Albanian, Spanish and Portuguese). The first data collection (baseline) took place in 2012 and the second is ongoing in 2014. For this paper, baseline data were analyzed. The study population was composed of men and women aged 65–74 years residing in communities within the above-mentioned cities. The sample was stratified by sex, and the aim was to recruit 200 men and 200 women at each site. Two recruitment methods were used, because in Canada the ethics committees did not allow direct contact with potential participants. In Kingston and Saint-Hyacinthe, potential participants were invited by a letter from their primary care physician to contact our field coordinator to participate in the study. Random samples with replacement were drawn from family practice lists of patients in the 65–74 age group. The family practices participating in the study came from all family medicine teams covering the territories of Kingston and Saint-Hyacinthe. In Saint-Hyacinthe the sample was stratified by neighbourhood, while in Kingston this stratification was not possible. In Tirana, Manizales and Natal, participants were randomly selected from the population in the 65–74 age group registered at neighbourhood health centres. Since Brazil and Albania have universal health coverage, practically all people in this age group are registered at the local primary care centre. In Colombia, the public healthcare network covers ~ 70% of older adults. Once participants were identified, interviewers made appointments for home visits to obtain informed consent and collect data. The Leganés cognitive test was administered at the beginning of the interview, and any participant with four or more errors on the orientation scale was excluded.23 Very few people (o 5) were excluded at each site. The survey questionnaire contained several sections: socio-demographic and economic characteristics, history of chronic diseases, ongoing treatment, falls, life course, quality of life, depression, cognitive function, lifestyle (physical activity, alcohol, tobacco, illicit drugs), social environment and living environment. Anthropometric and blood pressure (BP) measurements were taken. Response rates were 490% in Tirana, Manizales and Natal. In the Canadian cities, 95% of the subjects who contacted the field coordinator participated in the study. Of a total of 1995 participants surveyed, 13 were excluded because their BP was not measured. Outcome. BP was measured three times in succession on the same arm with the participant in a sitting position. Two brands of automatic devices were used: the Omron M3 (Omron Corp., Kyoto, Japan) in Tirana, Manizales and Natal, and the OSZ-5 (Welch Allyn, Skaneateles Falls, New York, NY, USA) in Kingston and Saint-Hyacinthe. The first measurement was taken after about 5 min of rest and the two others at successive 1-min intervals. The average of the last two measurements was considered to be the participant’s BP. Hypertension: Participants were classified as hypertensive if their systolic BP (SBP) ⩾ 140 mm Hg and/or their diastolic BP (DBP) ⩾ 90 mm Hg or if they were taking antihypertensive medication. Awareness: Participants with hypertension were considered to be aware of their condition if they answered positively to the question, ‘Have you ever been told by a doctor or a health professional that you have hypertension or elevated blood pressure?’. They were asked this question before the measurement of BP. Journal of Human Hypertension (2015), 1 – 8
Treatment: We asked participants, ‘Did you take any prescribed or over-
the-counter medications in the past 2 weeks?’ If the answer was ‘yes,’ the interviewer asked participants to show them all medical drug containers and recorded the drug names. Antihypertensive medications were identified using the World Health Organization’s Anatomical Therapeutic Chemical–Defined Daily Dose classification system. Participants who had at least one antihypertensive medication and were aware of their condition were considered to be under treatment. Control: Hypertension was considered to be controlled among pharmacologically treated participants if SBPo 140 mm Hg and DBP o90 mm Hg or, for individuals with diabetes, if SBPo 130 mm Hg and DBPo80 mm Hg.24 Independent variables. Education was assessed based on the highest level of schooling completed by participants. Responses were grouped into three categories: less than secondary school, secondary and post secondary. Income was assessed by asking the question, ‘Is your monthly income sufficient to cover basic needs?’ The answers were divided into three categories: very sufficient, sufficient and insufficient. Diabetes status was self-reported; participants were classified as having diabetes when they answered positively to the question, ‘Have you ever been told by a doctor or a health professional that you have diabetes?’. Height was measured without shoes, using a stadiometer. Weight was measured with an electronic scale after the participants had removed their outer garments and footwear. Body mass index was obtained by dividing the participants’ weight (kg) by the square of their height (m2). Three categories were established: o25 (underweight or normal weight), 25 to 29 (overweight) and ⩾ 30 (obese).25 Participants who smoked regularly or occasionally at the time of the survey were classified as current smokers, and those who had smoked in the past but had stopped by the time of the survey were classified as former smokers. For participants’ alcohol consumption, the question ‘How often do you usually drink alcohol?’ was asked. Participant was classified as ‘never’ when participants never drank alcohol, as ‘rare/moderate’ when participants drank alcohol equal or less than twice a week and as ‘frequent’ when participants drank alcohol more than twice a week. Physical activity was assessed according to the amount of time participants reported they spent walking during a regular week. The answers were grouped into two categories: ‘yes’ for those who reported 30 min per day or more, ‘no’ for those who reported less than 30 min per day.
Statistical analysis Results are summarized as counts and percentage for selected variables. χ2-tests were used to compare the proportions. Logistic regression analyses were used to investigate potential factors associated with hypertension prevalence, awareness, treatment and control. A P-value o0.05 was used to determine statistically significant results. The Stata V.11.0 software (StataCorp, College Station, TX, USA) was used for data analyses.
Ethics statement The study was approved by the ethics committees of the relevant institutions at each site: Queens University and the University of Montreal Hospital Research Centre in Canada; the Institute of Public Health in Albania; the University of Caldas in Colombia; and the Universidade Federal do Rio Grande do Norte in Brazil. All participants gave written informed consent.
RESULTS Table 1 shows participants’ sociodemographic and health characteristics. In four of the 5 five cities, the younger group (65–69 years) is larger than the older one (70–74 years) probably because of the distribution in the population due to higher mortality at older ages. Participants in Kingston, Saint-Hyacinthe and Tirana were better educated (o 12% had less than high school education) than those in Manizales and Natal. Less than 10% of participants from Kingston and Saint-Hyacinthe found their monthly income insufficient, against 21% in Tirana and at least 70% in Manizales and Natal. Of the five sites, Tirana and Natal had the highest prevalence of diabetes among participants (28.7% each), followed by Saint-Hyacinthe (19.2%). The prevalence of © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
53.6 46.4
Sex Men Women
46.4 53.6
47.3 52.7
47.7 49.5 52.3 50.5 P-value = 0.94
47.9 52.1
0.5
7.1
11.4
73.9
77.8
21.8 77.7
42.3 50.6
26.4 62.2
15.1 11.0
17.7 4.5
4.8
4.0
Education level Less than secondary Secondary Post secondary
P-valueo0.001 Income sufficiency Very 61.4 sufficient Sufficient 33.3 Insufficient 5.3
48.4 7.3
41.4 24.1 21.0 71.1 P-valueo0.001
21.9 74.1
Diabetes No Yes
86.6 13.4
80.8 19.2
71.3 86.4 28.7 13.6 P-valueo0.001
71.3 28.7
Body mass index o25 25–29 ⩾ 30
32.0 39.3 28.7
29.6 37.7 32.7
17.0 40.2 46.7 43.5 36.3 16.3 P-valueo0.001
30.2 43.4 26.4
Smoking Never former Current
44.4 51.0 4.6
36.7 56.7 6.6
60.7 48.5 26.9 41.5 12.4 10.0 P-valueo0.001
48.9 43.6 7.5
15.0 40.9
8.9 57.7
60.2 28.4
63.8 35.7
82.8 14.5
44.2
33.4
11.4 P valueo 0.001
0.5
2.7
72.3 27.7
55.4 77.0 44.6 23.0 P-valueo0.001
87.8 12.2
Alcohol intake Never Rare/ moderate Frequent
Walking430 min per day No 64.3 Yes 35.7
44.3
37.6
P-value were obtained by Χ2-test.
obesity was highest (36.3%) in Tirana, followed by the Canadian sites (Kingston: 28.7%; Saint-Hyacinthe: 32.7%). The proportions of participants who were current or former smokers and of those who frequently consumed alcohol were higher in Kingston and Saint-Hyacinthe. Former smokers quit smoking on average 24 years (s.d. = 14.3) ago. © 2015 Macmillan Publishers Limited
Kingston
Figure 1.
SaintHyacinthe
Tirana
Manizales
Women
49.5 53.5 50.5 46.5 P-value = 0.002
Men
63.5 36.5
Women
56.3 43.7
Men
Age 65–69 70–74
Women
Kingston SaintTirana Manizales Natal (n = 394) Hyacinthe (n = 394) (n = 398) (n = 401) (n = 395)
Men
Sites
Women
Variables
Men
Demographic, socioeconomic, and health characteristics (%) of the study population
Women
Table 1.
Men
3 100 90 80 70 60 50 40 30 20 10 0
Natal
Prevalence of hypertension by site and by sex.
The prevalence of hypertension was highest among participants in Tirana (men: 80.9% (75.2–86.5), women: 85.9% (81.1–90.7)) and lowest among those in Kingston (men: 59.0% (51.8–66.2), women: 55.0% (48.2–61.7)) and Saint-Hyacinthe (men: 52.9% (45.7–60.2), women: 53.8% (47.0–60.7)). Across all five sites, there was no significant difference in prevalence between men and women (Figure 1). However, adjusted multivariate analysis showed that diabetes and higher body mass index were positively associated with hypertension at all sites, as reported in Table 2. Associations of alcohol intake and walking 430 min per day with hypertension were inconsistent across sites. Only in Kingston was the current use of tobacco positively associated with hypertension. At each site, the proportion of hypertensive participants who were aware of their condition was at least 60%. Women had higher hypertension awareness than men in Saint-Hyacinthe (74.1 versus 59.6%; P = 0.03), Manizales (87.4 versus 74.6%; P = 0.006) and Natal (91.1 versus 75.9%; P o 0.001; Figure 2). Multivariate results in Table 3 show a strong link between diabetes and the awareness of hypertensive status across a majority of the sites: indeed, diabetes was positively associated with awareness in Kingston, Manizales and Natal, whereas in Saint-Hyacinthe and Tirana diabetic patients were no more likely to be aware of their hypertension than were subjects without diabetes. Similarly, overweight and obesity were associated with awareness only in Manizales and Natal. We would expect hypertension awareness to be associated with lower prevalence of risk behaviours, since a diagnosis of hypertension should be followed by the adoption of healthier behaviours: less smoking, less alcohol intake and more physical activity. However, hypertension awareness was not strongly or uniformly associated with lower prevalence of behavioural risk factors. Smoking had no consistent pattern of association with awareness across sites except in Manizales, where smoking was more frequent among those unaware of their hypertensive status. There was no consistent association with alcohol intake at any site. As for physical activity, only in Tirana were physically active subjects less likely to be aware of their hypertensive status. Figure 3 shows that treatment of hypertension among hypertensive individuals aware of their condition was 485% at all the sites and that no difference in the treatment by sex was observed. No factor was associated with hypertension treatment except current smoker status, which was negatively associated with treatment in Manizales (odds ratio (OR) = 0.13 (0.03–0.63)) and Natal (OR = 0.21 (0.06–0.77); results not shown). Figure 4 shows that control of hypertension among hypertensive patients under treatment was o 35% at two research sites (Tirana and Natal). Hypertension control was higher among women at all sites. Although the difference was not statistically significant, it did become significant at four sites when the significance threshold was set at 10%. Our adjusted model shows Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
4 Table 2.
Association of selected risk factors with prevalence of hypertension, by IMIAS study site
Variables
Sites Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
OR adjusted (95% CI)
OR adjusted (95% CI)
OR adjusted (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 0.86 (0.57–1.30)
1 1.00 (0.67–1.50)
1 1.41 (0.81–2.48)
1 0.87 (0.57–1.35)
1 1.22 (0.74–2.00)
Diabetes No Yes
1 2.47 (1.27–4.79)*
1 1.85 (1.07–3.19)*
1 4.97 (2.00–12.34)*
1 2.03 (1.01–4.09)*
1 1.84 (1.01–3.36)*
Body mass index o25 25–29 ⩾ 30
1 1.86 (1.14–3.02)* 3.65 (2.07–6.42)*
1 1.30 (0.79–2.12) 2.97 (1.74–5.05)*
1 1.39 (0.70–2.73) 3.23 (1.38–7.57)*
1 1.62 (1.02–2.57)* 3.68 (1.73–7.84)*
1 2.75 (1.57–4.80)* 4.63 (2.20–9.74)*
Smoking Never Former Current
1 1.25 (0.82–1.91) 4.34 (1.08–17.42)*
1.12 (0.72–1.74) 0.65 (0.28–1.54)
1 1.20 (0.62–2.32) 2.14 (0.77–5.97)
1 1.06 (0.66–1.70) 0.81 (0.38–1.74)
1 0.89 (0.53–1.49) 1.12 (0.41–3.02)
Alcohol intake Never Rare/moderate Frequent
1 1.06 (0.56–2.03) 0.70 (0.37–1.33)
1 1.76 (0.83–3.71) 1.85 (0.84–4.08)
1 1.39 (0.71–2.73) 1.19 (0.47–3.04)
1 0.67 (0.43–1.06) —
1 1.02 (0.50–2.09) 1.43 (0.27–7.42)
Walking 430min per day No 1 Yes 0.86 (0.56–1.32)
1 0.88 (0.55–1.43)
1 0.61 (0.35–1.06)
1 0.73 (0.44–1.20)
1 0.55 (0.28–1.10)
Kingston
SaintHyacinthe*
Tirana
Manizales*
Women
Men
Women
Men
Women
Men
Women
Men
Women
100 90 80 70 60 50 40 30 20 10 0
Men
Abbreviations: OR, odds ratios; 95% CI, 95% confidence interval; adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po0.05.
Natal*
Figure 2. Awareness of hypertension by site and by sex (*P value o0.05).
that diabetes was negatively associated with hypertension control across all sites. Contrary to expectations, there were no associations between maintaining normal weight and hypertension control except in Tirana. Likewise, we would expect that subjects with controlled BP would also have a lower prevalence of behavioural risk factors. Yet no associations were observed between smoking or alcohol consumption and hypertension control. Only walking 430 min per day was associated with hypertension control in Kingston (OR = 2.22 (1.02–5.00)), Manizales (OR = 2.56 (1.18–5.56)) and Natal (OR = 3.13 (1.12–9.09)), but not in Saint-Hyacinthe or Tirana (Table 4). Table 5 shows that hypertension control among all hypertensive participants was still lowest in Tirana and Natal, and Journal of Human Hypertension (2015), 1 – 8
women were more likely to achieve control in Saint-Hyacinthe, Manizales and Natal. Considering the new standard for hypertension control (BP o150/90 mm Hg for a person aged 60 years and over; BP o140/90 mm Hg for a person with diabetes) set by the Eighth Joint National Committee (JNC 8),26 control among hypertensive patients under treatment averaged 70% in Kingston, SaintHyacinthe and Manizales, compared with an average of 42% in Tirana and Natal. Only in Manizales did women have higher control of hypertension than men (Supplementary Table). DISCUSSION In this population-based sample aged between 65 and 74 years, we examined factors associated with prevalence, awareness, treatment and control of hypertension in different urban areas of Canada, Brazil, Colombia and Tirana. Hypertension prevalence was higher in Tirana, Manizales and Natal than in the Canadian cities of Kingston and Saint-Hyacinthe. Awareness and treatment were similar, and control of hypertension was generally low across all the sites. No sex differences in prevalence of hypertension were observed. However, women had generally better awareness and slightly better control than men. Diabetes and obesity were positively associated with hypertension prevalence and diabetes negatively affected hypertension control at all the sites. Obesity and diabetes were associated with awareness of hypertension at the three sites, as would be expected if people with these two serious chronic conditions were more likely to be screened for hypertension. Also, contrary to what might be expected, awareness of hypertension was not strongly or uniformly associated with lower prevalence of smoking, alcohol consumption or © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
5 Table 3.
Association of selected risk factors with hypertension awareness, by IMIAS study site
Variables
SItes Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 0.64 (0.34–1.19)
1 1.88 (1.02–3.45)*
1 1.22 (0.62–2.40)
1 2.36 (1.22–4.56)*
1 3.60 (1.88–6.92)*
Diabetes No Yes
1 4.45 (1.21–16.33)*
1 2.16 (0.95–4.95)
1 0.98 (0.49–1.95)
1 11.27 (1.58–80.67)*
1 3.79 (1.51–9.53)*
Body mass index o25 25–29 ⩾ 30
1 0.81 (0.36–1.82) 1.65 (0.70–3.87)
1 0.55 (0.24–1.23) 0.96 (0.43–2.17)
1 1.29 (0.55–3.06) 1.40 (0.56–3.55)
1 3.41 (1.67–7.00)* 4.27 (1.48–12.33)*
1 2.61 (1.28–5.32)* 4.23 (1.66–10.77)*
Smoking Never Former Current
1 0.71 (0.37–1.38) 0.63 (0.17–2.29)
1 1.34 (0.67–2.66) 1.12 (0.27–4.74)
1 2.24 (0.83–6.08) 0.98 (0.42–2.28)
1 0.68 (0.32–1.44) 0.23 (0.08–0.62)*
1 0.99 (0.50–1.98) 0.62 (0.21–1.83)
Alcohol intake Never Rare/moderate Frequent
1 0.79 (0.28–2.22) 0.46 (0.17–1.26)
1 1.71 (0.55–5.31) 2.87 (0.95–9.75)
1 2.36 (0.89–6.26) 3.16 (0.80–12.38)
1 0.61 (0.33–1.13) —
1 1.07 (0.46–2.51) 1.07 (0.23–4.97)
Walking 430mn per day No 1 Yes 0.81 (0.41–1.61)
1 1.23 (0.58–2.63)
1 0.47 (0.24–0.91)*
1 0.76 (0.36–1.59)
1 0.91 (0.33–2.40)
Abbreviations: OR, odds ratios; 95% CI, 95% confidence interval. Adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po0.05.
70 60 50 40 30 20
Figure 3. Treatment of hypertension among hypertensive participants who were aware of their condition, by site and by sex.
physical inactivity. As for control, physical activity as a health behaviour appeared to favour control of the condition among those being pharmacologically treated. We found that hypertension affected more than half of the older adults in our sample. Prevalence in Kingston and SaintHyacinthe was comparable to the 53% overall prevalence reported in Canada among people aged 60–79 years.14 The prevalence of hypertension in Tirana was almost twice as high as that reported in 2003 for residents of Tirana over 65 years of age.27 In fact, the results for Tirana were almost comparable to those of populations as diverse as those of France28 and South Africa, and higher than those found in a population of 50 years © 2015 Macmillan Publishers Limited
Kingston
Tirana
Manizales
Women
Men
Women
Men
Men
Men
Saint-Hyacinthe
Women
Natal
Men
Women
Men
Women
Manizales
Women
Tirana
Men
Women
Men
Women
SaintHyacinthe
0
Women
Kingston
Men
Women
10
Men
100 90 80 70 60 50 40 30 20 10 0
Natal
Figure 4. Control of hypertension among participants who were on antihypertensive medication, by site and by sex.
and over in the Russian Federation.12 In Albania, the fall of communism in 1992 and its replacement by a market economy has led to a breakdown in social protection systems and traditional networks, as well as to a more westernized lifestyle resulting in distress, poor nutrition and reduced physical activity.17,27 Such changes in people's lives might explain in part the high prevalence of hypertension. Hypertension prevalence in Manizales was higher for men and lower for women than that found among people aged 70–74 years in Mexico.29 It was lower than that found in Caracas (Venezuela) and in cities of the islands of Cuba, Dominican Republic and Puerto Rico.29 In Brazil, hypertension prevalence in Natal was higher than that recorded for other urban populations Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
6 Table 4.
Association of selected risk factors with hypertension control among IMIAS study participants who were on antihypertensive medication,
by site Variables
Sites Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 1.97 (0.99–3.91)
1 1.97 (0.88–4.38)
1 1.40 (0.80–2.46)
1 1.85 (1.03–3.33)*
1 1.69 (0.93–3.08)
Diabetes No Yes
1 0.39 (0.15–0.99)*
1 0.39 (0.15–0.99)*
1 0.30 (0.15–0.60)*
1 0.48 (0.23–0.98)*
1 0.32 (0.16–0.63)*
Body mass index o25 25–29 ⩾ 30
1 0.81 (0.31–2.12) 0.62 (0.25–1.54)
1 0.56 (0.20–1.61) 0.44 (0.17–1.13)
1 0.41 (0.19–0.89)* 0.53 (0.24–1.17)
1 1.11 (0.56–2.22) 0.76 (0.33–1.77)
1 1.11 (0.51–2.40) 0.64 (0.27–1.52)
Smoking Never Former Current
1 0.79 (0.39–1.60) 0.29 (0.02–4.12)
1 1.11 (0.45–2.73) 3.33 (0.63–17.71)
1 1.37 (0.64–2.91) 0.79 (0.33–1.89)
1 0.97 (0.52–1.83) 0.60 (0.15–2.36)
1 0.72 (0.39–1.33) 0.61 (0.16–2.33)
Alcohol intake Never Rare/moderate Frequent
1 1.20 (0.42–3.42) 1.01 (0.34–3.03)
1 1.68 (0.27–10.44) 2.74 (0.41–18.49)
1 1.58 (0.75–3.34) 0.84 (0.29–2.44)
1 1.45 (0.77–2.72) —
1 1.67 (0.70–3.98) —
1 0.89 (0.34–2.33)
1 0.90 (0.50–1.67)
1 2.56 (1.18–5.56)*
1 3.13 (1.12–9.09)*
Walking 430min per day No 1 Yes 2.22 (1.02–5.00)*
Abbreviations: OR, Odds ratios; 95% CI, 95% confidence interval. Adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po 0.05; hypertension control criteria were SBP o140 mm Hg and DBP o90 mm Hg or SBP o130 mm Hg and DBP o80 mm Hg if participant has diabetes.
Table 5.
Effective control of hypertension among all hypertensive IMIAS study participants, by site
Prevalence of control All Men Women P-value
Kingston (n = 224)
Saint-Hyacinthe (n = 211)
Tirana (n = 329)
Manizales (n = 271)
Natal (n = 313)
% (95% CI) 29.5 (23.4–35.5) 25.0 (16.7–33.3) 33.6 (24.9–42.3) 0.16
% (95% CI) 26.5 (20.5–32.5) 19.2 (11.3–27.1) 33.0 (24.2–41.9) 0.023
% (95% CI) 24.0 (19.4–28.7) 21.1 (14.5–27.6) 26.6 (20.0–33.1) 0.24
% (95% CI) 37.6 (31.8–43.4) 29.4 (21.7–37.2) 45.9 (37.4–54.4) 0.005
% (95% CI) 22.0 (17.4–26.7) 15.2 (9.3–21.1) 28.0 (21.1–34.8) 0.006
Abbreviation: 95% CI, 95% confidence interval. P-value were obtained by Χ2-test; hypertension control criteria were SBP o140 mm Hg and DBP o 90 mm Hg, or SBP o130 mm Hg and DBP o80 mm Hg if participant has diabetes.
of South Brazil.20,22 Prevalence in Natal was comparable to that reported in older Caribbean populations such as in Cuba, Dominican Republic and Puerto Rico.29 In Brazil, policies for the prevention and management of non-communicable diseases (anti-tobacco policy, healthy nutrition program and physical activity promotion) have been implemented, but the increasing trend towards obesity in the general population remains a challenge.30 We did not observe sex differences in prevalence of hypertension at any site. In this regard, our results did not corroborate previous findings among older adults in low- and middle-income countries, where prevalence was higher for women than for men,12,29 nor results reported in France and Ontario (Canada)28,31 where prevalence was higher among men. This inconsistency of association between sex and hypertension prevalence has also been reported by others.32 Journal of Human Hypertension (2015), 1 – 8
Obesity and diabetes are risk factors for hypertension in the IMIAS populations. These results are consistent with findings in other Latin American populations.33 The strong independent association between central obesity and hypertension is consistent with many findings in the literature.29 Our results suggest that the fight against hypertension should be incorporated into a larger fight against non-communicable diseases, as these diseases are sometime associated or share the same risk factors, even among advanced age groups. Although few previous studies have examined factors associated with awareness, treatment and control of hypertension in the elderly, we found some evidence to corroborate our results. We found hypertension awareness to be significantly higher in women at three sites; a similar observation was made in France among older urban populations28 and in low- and middle-income countries.12 Awareness in the Canadian cities of IMIAS was lower © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
7 than the high 87% awareness cited in the Canadian Health Measures Survey; however, no sex-specific estimates of awareness were published on that survey.14 The association we found between diabetes and awareness might suggest that diabetes patients are subject to more intense screening for hypertension at all the sites, but these associations are not uniform (not significant in Saint-Hyacinthe and Tirana). In addition, overweight and obese people are not consistently more aware of their hypertensive status, suggesting room for improvement in hypertension screening among overweight people, particularly in Kingston, SaintHyacinthe and Tirana. Associations between health behaviours (smoking, drinking alcohol and physical inactivity) and awareness are weak and inconsistent. This suggests that patients are not reducing their risk behaviours following the detection of hypertension. In fact, the converse was seen in Tirana, where being physically active was associated with a lower awareness of hypertension. This lack of reliance on non-pharmacological treatments should be the subject of more research since it may be due to a lack of medical prescription of non-pharmacological treatments or to a lack of patients’ willingness to modify behaviour or to a combination of the two. Results suggest that there is an almost complete reliance on pharmacological treatment. For all the five study sites, we found that almost all subjects aware of their status were under antihypertensive treatment. However, there was a drop in treatment among current smokers in Manizales and Tirana, possibly because they cared less about prevention. Among hypertensive elderly men in Costa Rica, current smokers were three times more likely to be unaware of their condition than were non-smokers.33 Hypertension control among people taking antihypertensive medication was generally low. This suggests low compliance by patients and low aggressiveness on the part of physicians with respect to hypertension management for older people. Control was lowest in Tirana and Natal, and highest in Kingston, SaintHyacinthe and Manizales. Among Tirana patients, lack of appropriate monitoring of hypertension and financial barriers might explain the lowest control. The country (Albania) is classified among the three worst examples in Europe in terms of hypertension control.34 Estimates of control of hypertension in IMIAS populations did not reach the high 66% estimated in the Canadian Health Measures Survey.14 In general, better control of hypertension has been observed in high-income countries.35 Our results show that control of hypertension remains a challenge for diabetics, and this corroborates previous results.31,36 While healthcare professionals in Canada were called upon in 2009 to increase efforts to help patients with diabetes achieve hypertension treatment targets (blood pressure below 130 mm Hg systolic and 80 mm Hg diastolic),37 the results of this initiative are not yet known. Physical inactivity was identified at three sites as a factor that reduced hypertension control. Thus, adapted physical activity remains a relevant recommendation for hypertensive older people. Control of hypertension tends to be higher in women than in men, probably because women are more compliant with treatment. We did not find an association between excess weight and hypertension control, contrary to results for elderly people in the Russian Federation, where overweight was negatively associated with hypertension control.12 Strengths and limitations of the study The main strengths of this study are its cross-cultural design and the common assessment protocol used across all five cities. This is one of very few studies to date to focus on older people. The major limitation of this study is the use of convenience sampling at the Canadian sites. We compared the education, income and marital status distributions of participants at Kingston © 2015 Macmillan Publishers Limited
and Saint-Hyacinthe with the 2006 Canadian census. There were no statistically significant differences for Saint-Hyacinthe, but the Kingston sample was more educated than average based on corresponding census data for Kingston for that age group, while being similar in income and marital status. Although the Canadian Health Measures Survey had a response rate of only 51%,14 it is reassuring that IMIAS prevalence and treatment figures are close to the ones reported in that survey for the group between 60 and 79 years of age. Outside of Canada, the samples were drawn at random and we are confident that they represent the base populations because the response rate was over 90% and there were no statistical differences in education or marital status between the IMIAS samples and the census data in Manizales and Natal. There was no information available on the Albanian census, but the participation rate in Tirana was also over 90%. As this was a cross-sectional survey, the correlates of hypertension cannot be assumed to be causally associated, and survival bias may have influenced some associations between risk factors and prevalence of hypertension. CONCLUSION Until recently, hypertension was associated with wealth, as suggested by its higher prevalence in developed countries. However, differences between developed and developing countries are decreasing, and in this study, we in fact observed a lower prevalence at the Canadian sites. Hypertension awareness and treatment ratios were generally satisfactory in the study populations. Patients with diabetes and obesity had better awareness only in some cities. Awareness was not associated with lower prevalence of behavioural factors (smoking, alcohol and physical inactivity), suggesting inadequate education and motivation by healthcare providers and/or a lack of adherence by patients to non-pharmacological treatments. Control was weaker in men and in diabetic patients. Among treated patients, being physically active was associated with better control. Prevention and control remain the largest challenge, especially in middle-income countries. Hypertension prevention programs should focus on overweight and obesity among the general adult population. Finally, efforts should be made to understand the lack of behaviour modification and of adherence to nonpharmacological treatments among persons who are aware of their hypertensive status. What is known about topic ● Worldwide cardiovascular diseases are a major cause of morbidity and mortality in elderly populations ● Hypertension is the main modifiable risk factor for theses cardiovascular diseases, but few international studies on hypertension older adults have been published What this study adds ● In diverse population of older adults, diabetes and obesity were positively associated with hypertension prevalence and hypertension awareness in every research site ● Hypertension awareness was not associated with lower prevalence of behavioural risk factors (smoking, alcohol and physical inactivity), suggesting inadequate education and motivation by health-care providers and/or a lack of adherence by patients to nonpharmacological treatments ● Diabetic patients and men had more difficulty in controlling their blood pressure
CONFLICT OF INTEREST The authors declare no conflict of interest.
Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
8
ACKNOWLEDGEMENTS We are grateful to all older adults who have given their time and confidence to this research. We thank our universities and institutes for providing continuous support and also thank our funding sources: the Canadian Institutes of Health (and the Institut de Santé Publique de l'Université de Montréal (IRSPUM)).
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19 Lima e Costa MF, Peixoto SV, Cesar CC, Malta DC, Moura EC. Health behaviors among older adults with hypertension, Brazil, 2006. Rev Saude Publica 2009; 43 (Suppl 2): 18–26. 20 Mendes Tde A, Goldbaum M, Segri NJ, Barros MB, Cesar CL, Carandina L. Factors associated with the prevalence of hypertension and control practices among elderly residents of Sao Paulo city, Brazil. Cad Saude Publica 2013; 29(11): 2275–2286. 21 Muniz LC, Cascaes AM, Wehrmeister FC, Martinez-Mesa J, Barros AJ, Menezes AM. Trends in self-reported arterial hypertension in Brazilian adults: an analysis of data from the Brazilian National Household Sample Survey, 1998–2008. Cad Saude Publica 2012; 28(8): 1599–1607. 22 Cipullo JP, Martin JF, Ciorlia LA, Godoy MR, Cacao JC, Loureiro AA et al. [Hypertension prevalence and risk factors in a Brazilian urban population]. Arq Bras Cardiol 2010; 94(4): 519–526. 23 De Yébenes MJ, Otero A, Zunzunegui MV, Rodriguez-Laso A, Sanchez-Sanchez F, Del Ser T. Validation of a short cognitive tool for the screening of dementia in elderly people with low educational level. Int J Geriatr Psychiatry 2003; 18(10): 925–936. 24 Hackam DG, Quinn RR, Ravani P, Rabi DM, Dasgupta K, Daskalopoulou SS et al. The 2013 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension. Can J Cardiol 2013; 29(5): 528–542. 25 World Health Organization. Obesity: Preventing and managing the global epidemic. WHO Technical Report Series 894. World Health Organization: Geneva, 2000. 26 James PA, Oparil S, Carter BL, Cushman WC, Dennison-Himmelfarb C, Handler J et al. evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA 2014; 311(5): 507–520. 27 Shapo L, Pomerleau J, McKee M. Epidemiology of hypertension and associated cardiovascular risk factors in a country in transition: a population based survey in Tirana City, Albania. J Epidemiol Community Health 2003; 57(9): 734–739. 28 Brindel P, Hanon O, Dartigues JF, Ritchie K, Lacombe JM, Ducimetiere P et al. Prevalence, awareness, treatment, and control of hypertension in the elderly: the Three City study. J Hypertens 2006; 24(1): 51–58. 29 Prince MJ, Ebrahim S, Acosta D, Ferri CP, Guerra M, Huang Y et al. Hypertension prevalence, awareness, treatment and control among older people in Latin America, India and China: a 10/66 cross-sectional population-based survey. J Hypertens 2012; 30(1): 177–187. 30 Schmidt MI, Duncan BB, Azevedo e Silva G, Menezes AM, Monteiro CA, Barreto SM et al. Chronic non-communicable diseases in Brazil: burden and current challenges. Lancet 2011; 377(9781): 1949–1961. 31 Leenen FH, Dumais J, McInnis NH, Turton P, Stratychuk L, Nemeth K et al. Results of the Ontario survey on the prevalence and control of hypertension. CMAJ 2008; 178(11): 1441–1449. 32 Pereira M, Lunet N, Azevedo A, Barros H. Differences in prevalence, awareness, treatment and control of hypertension between developing and developed countries. J Hypertens 2009; 27(5): 963–975. 33 Mendez-Chacon E, Santamaria-Ulloa C, Rosero-Bixby L. Factors associated with hypertension prevalence, unawareness and treatment among Costa Rican elderly. BMC Public Health 2008; 8: 275. 34 McKee M, Mackenbach J. Hypertension. In: McKee M, Mackenbach J (eds). Successes and Failures of Health Policies in Europe: Four Decades of Divergent Trends and Converging Challenges. McGraw-Hill Education: Maidenhead, England, 2013; pp 161–178. 35 Chow CK, Teo KK, Rangarajan S, Islam S, Gupta R, Avezum A et al. Prevalence, awareness, treatment, and control of hypertension in rural and urban communities in high-, middle-, and low-income countries. JAMA 2013; 310(9): 959–968. 36 Gee ME, Janssen I, Pickett W, McAlister FA, Bancej CM, Joffres M et al. Prevalence, awareness, treatment, and control of hypertension among Canadian adults with diabetes, 2007 to 2009. Can J Cardiol 2012; 28(3): 367–374. 37 Campbell NR, Leiter LA, Larochelle P, Tobe S, Chockalingam A, Ward R et al. Hypertension in diabetes: a call to action. Can J Cardiol 2009; 25(5): 299–302.
Supplementary Information accompanies this paper on the Journal of Human Hypertension website (http://www.nature.com/jhh)
Journal of Human Hypertension (2015), 1 – 8
© 2015 Macmillan Publishers Limited
ORIGINAL ARTICLE
Factors associated with hypertension prevalence, awareness, treatment and control among participants in the International Mobility in Aging Study (IMIAS) B Doulougou1,2, F Gomez3, B Alvarado4, RO Guerra5, A Ylli6, J Guralnik7 and MV Zunzunegui1 The aim of this study is to assess the factors associated with hypertension prevalence, awareness, treatment, and control, in the elderly populations of the International Mobility in Aging Study (IMIAS). Approximately 200 men and 200 women aged 65–74 years were recruited at each site (n = 1995) during IMIAS’ 2012 baseline survey at five cities: Kingston (Canada), Saint-Hyacinthe (Canada), Tirana (Albania), Manizales (Colombia) and Natal (Brazil). Blood pressure and anthropometric measurements were taken at participants’ homes. Hypertension prevalence ranged from 53.4% in Saint-Hyacinthe to 83.5% in Tirana. Diabetes and obesity were identified as risk factors in all cities. More than two-thirds of hypertensive participants were aware of their condition (from 67.3% in Saint-Hyacinthe to 85.4% in Tirana); women were more aware than men. Awareness was positively associated with diabetes in Kingston, Manizales and Natal. Though most of those aware of their hypertensive condition were being treated pharmacologically, associations between awareness and physical activity and refraining from smoking were weak. Control among treated hypertensive participants was low, especially in Tirana and Natal. Diabetes and physical inactivity were associated with poor hypertension control. Hypertension is common in the older populations of IMIAS. Diabetes is strongly associated with hypertension prevalence, awareness and lack of control of hypertension. The fact that awareness is not strongly associated with healthy behaviours suggests that antihypertensive medication is not accompanied by non-pharmacological therapies. Improved health behaviours could strengthen hypertension control. Efforts should be made to increase men’s awareness of hypertension. Hypertension control in diabetic patients is a challenge. Journal of Human Hypertension advance online publication, 2 April 2015; doi:10.1038/jhh.2015.30 INTRODUCTION Non-communicable diseases constitute a serious threat to population health and human development. A recommendation has been made to embed them in the post 2015 development agenda.1 The foremost group of these diseases is cardiovascular disease, which in 2008 caused 48% of global deaths due to non-communicable diseases.2 Hypertension is the leading modifiable risk factor for cardiovascular diseases3 and was the first leading risk factors for global disease burden in 2010.4 In 2000, 26% of the global adult population had hypertension and the number of hypertensive adults was predicted to increase to about 60% by 2025.5 Yet hypertension is a readily treatable risk factor for the most common causes of morbidity and mortality in older age (stroke, ischaemic heart disease, renal insufficiency, Alzheimer’s disease).6,7 The co-existence of diabetes and hypertension confers an enhanced risk of cardiovascular diseases.8–10 Hypertension prevalence increases with age. According to the World Health Organization trends, the number of people aged 65 years and older is projected to grow from an estimated 524 million in 2010 to nearly 1.5 billion in 2050, with the greatest increases in developing countries.11 So particular attention should be given to elderly populations at a risk of hypertension in those countries.
A recent study on hypertension among older adults in six low- and middle-income countries showed that hypertension prevalence was comparable to that of developed countries and that awareness was low.12 Knowledge about factors associated with hypertension prevalence, awareness and control among older adults in different regions of the world will contribute to global prevention and management of this chronic disease. The International Mobility in Aging Study (IMIAS) gives us an opportunity to examine hypertension problems among five distinct older adult urban populations from four countries with very different histories and healthcare systems—one high-income (Canada) and three middle-income (Brazil, Colombia and Albania). Many studies have been published on the prevalence of hypertension among adult populations across the world, but relatively little is known about hypertension issues specifically among older adults. In Canada, studies have examined prevalence, awareness, and control in populations 20 years of age and older but did not examine associated factors.13–15 Statistics Canada reports on the prevalence of self-reported hypertension, which was ~ 45% among persons aged 65–74 years in 2013.16 According to the 2007–2009 Canadian Health Measures Survey, hypertension prevalence for the 60–79 years old group was 53%, awareness was 86%, pharmacological treatment was received by 85% and control
1 École de Santé Publique de l’Université de Montréal (ESPUM), Montréal, Quebec, Canada; 2Département biomédical et santé publique, Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso; 3Research Group on Gerontology and Geriatrics, University of Caldas, Manizales, Colombia; 4Department of Public Health Sciences, Queen’s University, Kingston, Ontario, Canada; 5Department of Physiotherapy, Universidade Federal do Rio Grande do Norte, Natal, Brazil; 6National Institute of Public Health, Tirana, Albania and 7Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, Baltimore, MD, USA. Correspondence: B Doulougou, Département de Médecine Sociale et Préventive, École de Santé Publique, Université de Montréal, 850 Rue Saint Denis, 3ème étage, Bureau S03-806, Montréal, Quebec, Canada H2X 0A9. E-mail: [email protected] Received 15 January 2015; revised 23 February 2015; accepted 27 February 2015
Factors associated with hypertension in IMIAS participants B Doulougou et al
2
reached in 66% of those treated.14 Gaps in knowledge have been noted in recent studies of hypertension in Albania17 and Colombia.18 In Brazil, some studies have included older adult populations, but they are either limited to self-reported hypertension and do not report on treatment and control19–21 or else concern broader populations aged 18 years and over, with results published on the entire sample.22 Such studies do not provide specific knowledge regarding the burden of hypertension on elderly populations. Our aim was to assess the factors associated with hypertension prevalence, awareness, treatment and control in the elderly populations of the IMIAS study. METHODS The IMIAS study The IMIAS is a prospective cohort study conducted in five locations: Kingston (Ontario, Canada), Saint-Hyacinthe (Quebec, Canada), Tirana (Albania), Manizales (Colombia) and Natal (Brazil). Standardized training was given to all investigators and all documents were made available in all relevant languages (English, French, Albanian, Spanish and Portuguese). The first data collection (baseline) took place in 2012 and the second is ongoing in 2014. For this paper, baseline data were analyzed. The study population was composed of men and women aged 65–74 years residing in communities within the above-mentioned cities. The sample was stratified by sex, and the aim was to recruit 200 men and 200 women at each site. Two recruitment methods were used, because in Canada the ethics committees did not allow direct contact with potential participants. In Kingston and Saint-Hyacinthe, potential participants were invited by a letter from their primary care physician to contact our field coordinator to participate in the study. Random samples with replacement were drawn from family practice lists of patients in the 65–74 age group. The family practices participating in the study came from all family medicine teams covering the territories of Kingston and Saint-Hyacinthe. In Saint-Hyacinthe the sample was stratified by neighbourhood, while in Kingston this stratification was not possible. In Tirana, Manizales and Natal, participants were randomly selected from the population in the 65–74 age group registered at neighbourhood health centres. Since Brazil and Albania have universal health coverage, practically all people in this age group are registered at the local primary care centre. In Colombia, the public healthcare network covers ~ 70% of older adults. Once participants were identified, interviewers made appointments for home visits to obtain informed consent and collect data. The Leganés cognitive test was administered at the beginning of the interview, and any participant with four or more errors on the orientation scale was excluded.23 Very few people (o 5) were excluded at each site. The survey questionnaire contained several sections: socio-demographic and economic characteristics, history of chronic diseases, ongoing treatment, falls, life course, quality of life, depression, cognitive function, lifestyle (physical activity, alcohol, tobacco, illicit drugs), social environment and living environment. Anthropometric and blood pressure (BP) measurements were taken. Response rates were 490% in Tirana, Manizales and Natal. In the Canadian cities, 95% of the subjects who contacted the field coordinator participated in the study. Of a total of 1995 participants surveyed, 13 were excluded because their BP was not measured. Outcome. BP was measured three times in succession on the same arm with the participant in a sitting position. Two brands of automatic devices were used: the Omron M3 (Omron Corp., Kyoto, Japan) in Tirana, Manizales and Natal, and the OSZ-5 (Welch Allyn, Skaneateles Falls, New York, NY, USA) in Kingston and Saint-Hyacinthe. The first measurement was taken after about 5 min of rest and the two others at successive 1-min intervals. The average of the last two measurements was considered to be the participant’s BP. Hypertension: Participants were classified as hypertensive if their systolic BP (SBP) ⩾ 140 mm Hg and/or their diastolic BP (DBP) ⩾ 90 mm Hg or if they were taking antihypertensive medication. Awareness: Participants with hypertension were considered to be aware of their condition if they answered positively to the question, ‘Have you ever been told by a doctor or a health professional that you have hypertension or elevated blood pressure?’. They were asked this question before the measurement of BP. Journal of Human Hypertension (2015), 1 – 8
Treatment: We asked participants, ‘Did you take any prescribed or over-
the-counter medications in the past 2 weeks?’ If the answer was ‘yes,’ the interviewer asked participants to show them all medical drug containers and recorded the drug names. Antihypertensive medications were identified using the World Health Organization’s Anatomical Therapeutic Chemical–Defined Daily Dose classification system. Participants who had at least one antihypertensive medication and were aware of their condition were considered to be under treatment. Control: Hypertension was considered to be controlled among pharmacologically treated participants if SBPo 140 mm Hg and DBP o90 mm Hg or, for individuals with diabetes, if SBPo 130 mm Hg and DBPo80 mm Hg.24 Independent variables. Education was assessed based on the highest level of schooling completed by participants. Responses were grouped into three categories: less than secondary school, secondary and post secondary. Income was assessed by asking the question, ‘Is your monthly income sufficient to cover basic needs?’ The answers were divided into three categories: very sufficient, sufficient and insufficient. Diabetes status was self-reported; participants were classified as having diabetes when they answered positively to the question, ‘Have you ever been told by a doctor or a health professional that you have diabetes?’. Height was measured without shoes, using a stadiometer. Weight was measured with an electronic scale after the participants had removed their outer garments and footwear. Body mass index was obtained by dividing the participants’ weight (kg) by the square of their height (m2). Three categories were established: o25 (underweight or normal weight), 25 to 29 (overweight) and ⩾ 30 (obese).25 Participants who smoked regularly or occasionally at the time of the survey were classified as current smokers, and those who had smoked in the past but had stopped by the time of the survey were classified as former smokers. For participants’ alcohol consumption, the question ‘How often do you usually drink alcohol?’ was asked. Participant was classified as ‘never’ when participants never drank alcohol, as ‘rare/moderate’ when participants drank alcohol equal or less than twice a week and as ‘frequent’ when participants drank alcohol more than twice a week. Physical activity was assessed according to the amount of time participants reported they spent walking during a regular week. The answers were grouped into two categories: ‘yes’ for those who reported 30 min per day or more, ‘no’ for those who reported less than 30 min per day.
Statistical analysis Results are summarized as counts and percentage for selected variables. χ2-tests were used to compare the proportions. Logistic regression analyses were used to investigate potential factors associated with hypertension prevalence, awareness, treatment and control. A P-value o0.05 was used to determine statistically significant results. The Stata V.11.0 software (StataCorp, College Station, TX, USA) was used for data analyses.
Ethics statement The study was approved by the ethics committees of the relevant institutions at each site: Queens University and the University of Montreal Hospital Research Centre in Canada; the Institute of Public Health in Albania; the University of Caldas in Colombia; and the Universidade Federal do Rio Grande do Norte in Brazil. All participants gave written informed consent.
RESULTS Table 1 shows participants’ sociodemographic and health characteristics. In four of the 5 five cities, the younger group (65–69 years) is larger than the older one (70–74 years) probably because of the distribution in the population due to higher mortality at older ages. Participants in Kingston, Saint-Hyacinthe and Tirana were better educated (o 12% had less than high school education) than those in Manizales and Natal. Less than 10% of participants from Kingston and Saint-Hyacinthe found their monthly income insufficient, against 21% in Tirana and at least 70% in Manizales and Natal. Of the five sites, Tirana and Natal had the highest prevalence of diabetes among participants (28.7% each), followed by Saint-Hyacinthe (19.2%). The prevalence of © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
53.6 46.4
Sex Men Women
46.4 53.6
47.3 52.7
47.7 49.5 52.3 50.5 P-value = 0.94
47.9 52.1
0.5
7.1
11.4
73.9
77.8
21.8 77.7
42.3 50.6
26.4 62.2
15.1 11.0
17.7 4.5
4.8
4.0
Education level Less than secondary Secondary Post secondary
P-valueo0.001 Income sufficiency Very 61.4 sufficient Sufficient 33.3 Insufficient 5.3
48.4 7.3
41.4 24.1 21.0 71.1 P-valueo0.001
21.9 74.1
Diabetes No Yes
86.6 13.4
80.8 19.2
71.3 86.4 28.7 13.6 P-valueo0.001
71.3 28.7
Body mass index o25 25–29 ⩾ 30
32.0 39.3 28.7
29.6 37.7 32.7
17.0 40.2 46.7 43.5 36.3 16.3 P-valueo0.001
30.2 43.4 26.4
Smoking Never former Current
44.4 51.0 4.6
36.7 56.7 6.6
60.7 48.5 26.9 41.5 12.4 10.0 P-valueo0.001
48.9 43.6 7.5
15.0 40.9
8.9 57.7
60.2 28.4
63.8 35.7
82.8 14.5
44.2
33.4
11.4 P valueo 0.001
0.5
2.7
72.3 27.7
55.4 77.0 44.6 23.0 P-valueo0.001
87.8 12.2
Alcohol intake Never Rare/ moderate Frequent
Walking430 min per day No 64.3 Yes 35.7
44.3
37.6
P-value were obtained by Χ2-test.
obesity was highest (36.3%) in Tirana, followed by the Canadian sites (Kingston: 28.7%; Saint-Hyacinthe: 32.7%). The proportions of participants who were current or former smokers and of those who frequently consumed alcohol were higher in Kingston and Saint-Hyacinthe. Former smokers quit smoking on average 24 years (s.d. = 14.3) ago. © 2015 Macmillan Publishers Limited
Kingston
Figure 1.
SaintHyacinthe
Tirana
Manizales
Women
49.5 53.5 50.5 46.5 P-value = 0.002
Men
63.5 36.5
Women
56.3 43.7
Men
Age 65–69 70–74
Women
Kingston SaintTirana Manizales Natal (n = 394) Hyacinthe (n = 394) (n = 398) (n = 401) (n = 395)
Men
Sites
Women
Variables
Men
Demographic, socioeconomic, and health characteristics (%) of the study population
Women
Table 1.
Men
3 100 90 80 70 60 50 40 30 20 10 0
Natal
Prevalence of hypertension by site and by sex.
The prevalence of hypertension was highest among participants in Tirana (men: 80.9% (75.2–86.5), women: 85.9% (81.1–90.7)) and lowest among those in Kingston (men: 59.0% (51.8–66.2), women: 55.0% (48.2–61.7)) and Saint-Hyacinthe (men: 52.9% (45.7–60.2), women: 53.8% (47.0–60.7)). Across all five sites, there was no significant difference in prevalence between men and women (Figure 1). However, adjusted multivariate analysis showed that diabetes and higher body mass index were positively associated with hypertension at all sites, as reported in Table 2. Associations of alcohol intake and walking 430 min per day with hypertension were inconsistent across sites. Only in Kingston was the current use of tobacco positively associated with hypertension. At each site, the proportion of hypertensive participants who were aware of their condition was at least 60%. Women had higher hypertension awareness than men in Saint-Hyacinthe (74.1 versus 59.6%; P = 0.03), Manizales (87.4 versus 74.6%; P = 0.006) and Natal (91.1 versus 75.9%; P o 0.001; Figure 2). Multivariate results in Table 3 show a strong link between diabetes and the awareness of hypertensive status across a majority of the sites: indeed, diabetes was positively associated with awareness in Kingston, Manizales and Natal, whereas in Saint-Hyacinthe and Tirana diabetic patients were no more likely to be aware of their hypertension than were subjects without diabetes. Similarly, overweight and obesity were associated with awareness only in Manizales and Natal. We would expect hypertension awareness to be associated with lower prevalence of risk behaviours, since a diagnosis of hypertension should be followed by the adoption of healthier behaviours: less smoking, less alcohol intake and more physical activity. However, hypertension awareness was not strongly or uniformly associated with lower prevalence of behavioural risk factors. Smoking had no consistent pattern of association with awareness across sites except in Manizales, where smoking was more frequent among those unaware of their hypertensive status. There was no consistent association with alcohol intake at any site. As for physical activity, only in Tirana were physically active subjects less likely to be aware of their hypertensive status. Figure 3 shows that treatment of hypertension among hypertensive individuals aware of their condition was 485% at all the sites and that no difference in the treatment by sex was observed. No factor was associated with hypertension treatment except current smoker status, which was negatively associated with treatment in Manizales (odds ratio (OR) = 0.13 (0.03–0.63)) and Natal (OR = 0.21 (0.06–0.77); results not shown). Figure 4 shows that control of hypertension among hypertensive patients under treatment was o 35% at two research sites (Tirana and Natal). Hypertension control was higher among women at all sites. Although the difference was not statistically significant, it did become significant at four sites when the significance threshold was set at 10%. Our adjusted model shows Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
4 Table 2.
Association of selected risk factors with prevalence of hypertension, by IMIAS study site
Variables
Sites Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
OR adjusted (95% CI)
OR adjusted (95% CI)
OR adjusted (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 0.86 (0.57–1.30)
1 1.00 (0.67–1.50)
1 1.41 (0.81–2.48)
1 0.87 (0.57–1.35)
1 1.22 (0.74–2.00)
Diabetes No Yes
1 2.47 (1.27–4.79)*
1 1.85 (1.07–3.19)*
1 4.97 (2.00–12.34)*
1 2.03 (1.01–4.09)*
1 1.84 (1.01–3.36)*
Body mass index o25 25–29 ⩾ 30
1 1.86 (1.14–3.02)* 3.65 (2.07–6.42)*
1 1.30 (0.79–2.12) 2.97 (1.74–5.05)*
1 1.39 (0.70–2.73) 3.23 (1.38–7.57)*
1 1.62 (1.02–2.57)* 3.68 (1.73–7.84)*
1 2.75 (1.57–4.80)* 4.63 (2.20–9.74)*
Smoking Never Former Current
1 1.25 (0.82–1.91) 4.34 (1.08–17.42)*
1.12 (0.72–1.74) 0.65 (0.28–1.54)
1 1.20 (0.62–2.32) 2.14 (0.77–5.97)
1 1.06 (0.66–1.70) 0.81 (0.38–1.74)
1 0.89 (0.53–1.49) 1.12 (0.41–3.02)
Alcohol intake Never Rare/moderate Frequent
1 1.06 (0.56–2.03) 0.70 (0.37–1.33)
1 1.76 (0.83–3.71) 1.85 (0.84–4.08)
1 1.39 (0.71–2.73) 1.19 (0.47–3.04)
1 0.67 (0.43–1.06) —
1 1.02 (0.50–2.09) 1.43 (0.27–7.42)
Walking 430min per day No 1 Yes 0.86 (0.56–1.32)
1 0.88 (0.55–1.43)
1 0.61 (0.35–1.06)
1 0.73 (0.44–1.20)
1 0.55 (0.28–1.10)
Kingston
SaintHyacinthe*
Tirana
Manizales*
Women
Men
Women
Men
Women
Men
Women
Men
Women
100 90 80 70 60 50 40 30 20 10 0
Men
Abbreviations: OR, odds ratios; 95% CI, 95% confidence interval; adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po0.05.
Natal*
Figure 2. Awareness of hypertension by site and by sex (*P value o0.05).
that diabetes was negatively associated with hypertension control across all sites. Contrary to expectations, there were no associations between maintaining normal weight and hypertension control except in Tirana. Likewise, we would expect that subjects with controlled BP would also have a lower prevalence of behavioural risk factors. Yet no associations were observed between smoking or alcohol consumption and hypertension control. Only walking 430 min per day was associated with hypertension control in Kingston (OR = 2.22 (1.02–5.00)), Manizales (OR = 2.56 (1.18–5.56)) and Natal (OR = 3.13 (1.12–9.09)), but not in Saint-Hyacinthe or Tirana (Table 4). Table 5 shows that hypertension control among all hypertensive participants was still lowest in Tirana and Natal, and Journal of Human Hypertension (2015), 1 – 8
women were more likely to achieve control in Saint-Hyacinthe, Manizales and Natal. Considering the new standard for hypertension control (BP o150/90 mm Hg for a person aged 60 years and over; BP o140/90 mm Hg for a person with diabetes) set by the Eighth Joint National Committee (JNC 8),26 control among hypertensive patients under treatment averaged 70% in Kingston, SaintHyacinthe and Manizales, compared with an average of 42% in Tirana and Natal. Only in Manizales did women have higher control of hypertension than men (Supplementary Table). DISCUSSION In this population-based sample aged between 65 and 74 years, we examined factors associated with prevalence, awareness, treatment and control of hypertension in different urban areas of Canada, Brazil, Colombia and Tirana. Hypertension prevalence was higher in Tirana, Manizales and Natal than in the Canadian cities of Kingston and Saint-Hyacinthe. Awareness and treatment were similar, and control of hypertension was generally low across all the sites. No sex differences in prevalence of hypertension were observed. However, women had generally better awareness and slightly better control than men. Diabetes and obesity were positively associated with hypertension prevalence and diabetes negatively affected hypertension control at all the sites. Obesity and diabetes were associated with awareness of hypertension at the three sites, as would be expected if people with these two serious chronic conditions were more likely to be screened for hypertension. Also, contrary to what might be expected, awareness of hypertension was not strongly or uniformly associated with lower prevalence of smoking, alcohol consumption or © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
5 Table 3.
Association of selected risk factors with hypertension awareness, by IMIAS study site
Variables
SItes Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 0.64 (0.34–1.19)
1 1.88 (1.02–3.45)*
1 1.22 (0.62–2.40)
1 2.36 (1.22–4.56)*
1 3.60 (1.88–6.92)*
Diabetes No Yes
1 4.45 (1.21–16.33)*
1 2.16 (0.95–4.95)
1 0.98 (0.49–1.95)
1 11.27 (1.58–80.67)*
1 3.79 (1.51–9.53)*
Body mass index o25 25–29 ⩾ 30
1 0.81 (0.36–1.82) 1.65 (0.70–3.87)
1 0.55 (0.24–1.23) 0.96 (0.43–2.17)
1 1.29 (0.55–3.06) 1.40 (0.56–3.55)
1 3.41 (1.67–7.00)* 4.27 (1.48–12.33)*
1 2.61 (1.28–5.32)* 4.23 (1.66–10.77)*
Smoking Never Former Current
1 0.71 (0.37–1.38) 0.63 (0.17–2.29)
1 1.34 (0.67–2.66) 1.12 (0.27–4.74)
1 2.24 (0.83–6.08) 0.98 (0.42–2.28)
1 0.68 (0.32–1.44) 0.23 (0.08–0.62)*
1 0.99 (0.50–1.98) 0.62 (0.21–1.83)
Alcohol intake Never Rare/moderate Frequent
1 0.79 (0.28–2.22) 0.46 (0.17–1.26)
1 1.71 (0.55–5.31) 2.87 (0.95–9.75)
1 2.36 (0.89–6.26) 3.16 (0.80–12.38)
1 0.61 (0.33–1.13) —
1 1.07 (0.46–2.51) 1.07 (0.23–4.97)
Walking 430mn per day No 1 Yes 0.81 (0.41–1.61)
1 1.23 (0.58–2.63)
1 0.47 (0.24–0.91)*
1 0.76 (0.36–1.59)
1 0.91 (0.33–2.40)
Abbreviations: OR, odds ratios; 95% CI, 95% confidence interval. Adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po0.05.
70 60 50 40 30 20
Figure 3. Treatment of hypertension among hypertensive participants who were aware of their condition, by site and by sex.
physical inactivity. As for control, physical activity as a health behaviour appeared to favour control of the condition among those being pharmacologically treated. We found that hypertension affected more than half of the older adults in our sample. Prevalence in Kingston and SaintHyacinthe was comparable to the 53% overall prevalence reported in Canada among people aged 60–79 years.14 The prevalence of hypertension in Tirana was almost twice as high as that reported in 2003 for residents of Tirana over 65 years of age.27 In fact, the results for Tirana were almost comparable to those of populations as diverse as those of France28 and South Africa, and higher than those found in a population of 50 years © 2015 Macmillan Publishers Limited
Kingston
Tirana
Manizales
Women
Men
Women
Men
Men
Men
Saint-Hyacinthe
Women
Natal
Men
Women
Men
Women
Manizales
Women
Tirana
Men
Women
Men
Women
SaintHyacinthe
0
Women
Kingston
Men
Women
10
Men
100 90 80 70 60 50 40 30 20 10 0
Natal
Figure 4. Control of hypertension among participants who were on antihypertensive medication, by site and by sex.
and over in the Russian Federation.12 In Albania, the fall of communism in 1992 and its replacement by a market economy has led to a breakdown in social protection systems and traditional networks, as well as to a more westernized lifestyle resulting in distress, poor nutrition and reduced physical activity.17,27 Such changes in people's lives might explain in part the high prevalence of hypertension. Hypertension prevalence in Manizales was higher for men and lower for women than that found among people aged 70–74 years in Mexico.29 It was lower than that found in Caracas (Venezuela) and in cities of the islands of Cuba, Dominican Republic and Puerto Rico.29 In Brazil, hypertension prevalence in Natal was higher than that recorded for other urban populations Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
6 Table 4.
Association of selected risk factors with hypertension control among IMIAS study participants who were on antihypertensive medication,
by site Variables
Sites Kingston
Saint-Hyacinthe
Tirana
Manizales
Natal
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Adjusted OR (95% CI)
Sex Men Women
1 1.97 (0.99–3.91)
1 1.97 (0.88–4.38)
1 1.40 (0.80–2.46)
1 1.85 (1.03–3.33)*
1 1.69 (0.93–3.08)
Diabetes No Yes
1 0.39 (0.15–0.99)*
1 0.39 (0.15–0.99)*
1 0.30 (0.15–0.60)*
1 0.48 (0.23–0.98)*
1 0.32 (0.16–0.63)*
Body mass index o25 25–29 ⩾ 30
1 0.81 (0.31–2.12) 0.62 (0.25–1.54)
1 0.56 (0.20–1.61) 0.44 (0.17–1.13)
1 0.41 (0.19–0.89)* 0.53 (0.24–1.17)
1 1.11 (0.56–2.22) 0.76 (0.33–1.77)
1 1.11 (0.51–2.40) 0.64 (0.27–1.52)
Smoking Never Former Current
1 0.79 (0.39–1.60) 0.29 (0.02–4.12)
1 1.11 (0.45–2.73) 3.33 (0.63–17.71)
1 1.37 (0.64–2.91) 0.79 (0.33–1.89)
1 0.97 (0.52–1.83) 0.60 (0.15–2.36)
1 0.72 (0.39–1.33) 0.61 (0.16–2.33)
Alcohol intake Never Rare/moderate Frequent
1 1.20 (0.42–3.42) 1.01 (0.34–3.03)
1 1.68 (0.27–10.44) 2.74 (0.41–18.49)
1 1.58 (0.75–3.34) 0.84 (0.29–2.44)
1 1.45 (0.77–2.72) —
1 1.67 (0.70–3.98) —
1 0.89 (0.34–2.33)
1 0.90 (0.50–1.67)
1 2.56 (1.18–5.56)*
1 3.13 (1.12–9.09)*
Walking 430min per day No 1 Yes 2.22 (1.02–5.00)*
Abbreviations: OR, Odds ratios; 95% CI, 95% confidence interval. Adjusted for sex, age, education and income sufficiency. P-values were obtained by Wald tests; *Po 0.05; hypertension control criteria were SBP o140 mm Hg and DBP o90 mm Hg or SBP o130 mm Hg and DBP o80 mm Hg if participant has diabetes.
Table 5.
Effective control of hypertension among all hypertensive IMIAS study participants, by site
Prevalence of control All Men Women P-value
Kingston (n = 224)
Saint-Hyacinthe (n = 211)
Tirana (n = 329)
Manizales (n = 271)
Natal (n = 313)
% (95% CI) 29.5 (23.4–35.5) 25.0 (16.7–33.3) 33.6 (24.9–42.3) 0.16
% (95% CI) 26.5 (20.5–32.5) 19.2 (11.3–27.1) 33.0 (24.2–41.9) 0.023
% (95% CI) 24.0 (19.4–28.7) 21.1 (14.5–27.6) 26.6 (20.0–33.1) 0.24
% (95% CI) 37.6 (31.8–43.4) 29.4 (21.7–37.2) 45.9 (37.4–54.4) 0.005
% (95% CI) 22.0 (17.4–26.7) 15.2 (9.3–21.1) 28.0 (21.1–34.8) 0.006
Abbreviation: 95% CI, 95% confidence interval. P-value were obtained by Χ2-test; hypertension control criteria were SBP o140 mm Hg and DBP o 90 mm Hg, or SBP o130 mm Hg and DBP o80 mm Hg if participant has diabetes.
of South Brazil.20,22 Prevalence in Natal was comparable to that reported in older Caribbean populations such as in Cuba, Dominican Republic and Puerto Rico.29 In Brazil, policies for the prevention and management of non-communicable diseases (anti-tobacco policy, healthy nutrition program and physical activity promotion) have been implemented, but the increasing trend towards obesity in the general population remains a challenge.30 We did not observe sex differences in prevalence of hypertension at any site. In this regard, our results did not corroborate previous findings among older adults in low- and middle-income countries, where prevalence was higher for women than for men,12,29 nor results reported in France and Ontario (Canada)28,31 where prevalence was higher among men. This inconsistency of association between sex and hypertension prevalence has also been reported by others.32 Journal of Human Hypertension (2015), 1 – 8
Obesity and diabetes are risk factors for hypertension in the IMIAS populations. These results are consistent with findings in other Latin American populations.33 The strong independent association between central obesity and hypertension is consistent with many findings in the literature.29 Our results suggest that the fight against hypertension should be incorporated into a larger fight against non-communicable diseases, as these diseases are sometime associated or share the same risk factors, even among advanced age groups. Although few previous studies have examined factors associated with awareness, treatment and control of hypertension in the elderly, we found some evidence to corroborate our results. We found hypertension awareness to be significantly higher in women at three sites; a similar observation was made in France among older urban populations28 and in low- and middle-income countries.12 Awareness in the Canadian cities of IMIAS was lower © 2015 Macmillan Publishers Limited
Factors associated with hypertension in IMIAS participants B Doulougou et al
7 than the high 87% awareness cited in the Canadian Health Measures Survey; however, no sex-specific estimates of awareness were published on that survey.14 The association we found between diabetes and awareness might suggest that diabetes patients are subject to more intense screening for hypertension at all the sites, but these associations are not uniform (not significant in Saint-Hyacinthe and Tirana). In addition, overweight and obese people are not consistently more aware of their hypertensive status, suggesting room for improvement in hypertension screening among overweight people, particularly in Kingston, SaintHyacinthe and Tirana. Associations between health behaviours (smoking, drinking alcohol and physical inactivity) and awareness are weak and inconsistent. This suggests that patients are not reducing their risk behaviours following the detection of hypertension. In fact, the converse was seen in Tirana, where being physically active was associated with a lower awareness of hypertension. This lack of reliance on non-pharmacological treatments should be the subject of more research since it may be due to a lack of medical prescription of non-pharmacological treatments or to a lack of patients’ willingness to modify behaviour or to a combination of the two. Results suggest that there is an almost complete reliance on pharmacological treatment. For all the five study sites, we found that almost all subjects aware of their status were under antihypertensive treatment. However, there was a drop in treatment among current smokers in Manizales and Tirana, possibly because they cared less about prevention. Among hypertensive elderly men in Costa Rica, current smokers were three times more likely to be unaware of their condition than were non-smokers.33 Hypertension control among people taking antihypertensive medication was generally low. This suggests low compliance by patients and low aggressiveness on the part of physicians with respect to hypertension management for older people. Control was lowest in Tirana and Natal, and highest in Kingston, SaintHyacinthe and Manizales. Among Tirana patients, lack of appropriate monitoring of hypertension and financial barriers might explain the lowest control. The country (Albania) is classified among the three worst examples in Europe in terms of hypertension control.34 Estimates of control of hypertension in IMIAS populations did not reach the high 66% estimated in the Canadian Health Measures Survey.14 In general, better control of hypertension has been observed in high-income countries.35 Our results show that control of hypertension remains a challenge for diabetics, and this corroborates previous results.31,36 While healthcare professionals in Canada were called upon in 2009 to increase efforts to help patients with diabetes achieve hypertension treatment targets (blood pressure below 130 mm Hg systolic and 80 mm Hg diastolic),37 the results of this initiative are not yet known. Physical inactivity was identified at three sites as a factor that reduced hypertension control. Thus, adapted physical activity remains a relevant recommendation for hypertensive older people. Control of hypertension tends to be higher in women than in men, probably because women are more compliant with treatment. We did not find an association between excess weight and hypertension control, contrary to results for elderly people in the Russian Federation, where overweight was negatively associated with hypertension control.12 Strengths and limitations of the study The main strengths of this study are its cross-cultural design and the common assessment protocol used across all five cities. This is one of very few studies to date to focus on older people. The major limitation of this study is the use of convenience sampling at the Canadian sites. We compared the education, income and marital status distributions of participants at Kingston © 2015 Macmillan Publishers Limited
and Saint-Hyacinthe with the 2006 Canadian census. There were no statistically significant differences for Saint-Hyacinthe, but the Kingston sample was more educated than average based on corresponding census data for Kingston for that age group, while being similar in income and marital status. Although the Canadian Health Measures Survey had a response rate of only 51%,14 it is reassuring that IMIAS prevalence and treatment figures are close to the ones reported in that survey for the group between 60 and 79 years of age. Outside of Canada, the samples were drawn at random and we are confident that they represent the base populations because the response rate was over 90% and there were no statistical differences in education or marital status between the IMIAS samples and the census data in Manizales and Natal. There was no information available on the Albanian census, but the participation rate in Tirana was also over 90%. As this was a cross-sectional survey, the correlates of hypertension cannot be assumed to be causally associated, and survival bias may have influenced some associations between risk factors and prevalence of hypertension. CONCLUSION Until recently, hypertension was associated with wealth, as suggested by its higher prevalence in developed countries. However, differences between developed and developing countries are decreasing, and in this study, we in fact observed a lower prevalence at the Canadian sites. Hypertension awareness and treatment ratios were generally satisfactory in the study populations. Patients with diabetes and obesity had better awareness only in some cities. Awareness was not associated with lower prevalence of behavioural factors (smoking, alcohol and physical inactivity), suggesting inadequate education and motivation by healthcare providers and/or a lack of adherence by patients to non-pharmacological treatments. Control was weaker in men and in diabetic patients. Among treated patients, being physically active was associated with better control. Prevention and control remain the largest challenge, especially in middle-income countries. Hypertension prevention programs should focus on overweight and obesity among the general adult population. Finally, efforts should be made to understand the lack of behaviour modification and of adherence to nonpharmacological treatments among persons who are aware of their hypertensive status. What is known about topic ● Worldwide cardiovascular diseases are a major cause of morbidity and mortality in elderly populations ● Hypertension is the main modifiable risk factor for theses cardiovascular diseases, but few international studies on hypertension older adults have been published What this study adds ● In diverse population of older adults, diabetes and obesity were positively associated with hypertension prevalence and hypertension awareness in every research site ● Hypertension awareness was not associated with lower prevalence of behavioural risk factors (smoking, alcohol and physical inactivity), suggesting inadequate education and motivation by health-care providers and/or a lack of adherence by patients to nonpharmacological treatments ● Diabetic patients and men had more difficulty in controlling their blood pressure
CONFLICT OF INTEREST The authors declare no conflict of interest.
Journal of Human Hypertension (2015), 1 – 8
Factors associated with hypertension in IMIAS participants B Doulougou et al
8
ACKNOWLEDGEMENTS We are grateful to all older adults who have given their time and confidence to this research. We thank our universities and institutes for providing continuous support and also thank our funding sources: the Canadian Institutes of Health (and the Institut de Santé Publique de l'Université de Montréal (IRSPUM)).
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Journal of Human Hypertension (2015), 1 – 8
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