J Nutr Health Aging
THE JOURNAL OF NUTRITION, HEALTH & AGING©
ASSOCIATION BETWEEN DIET QUALITY WITH CONCURRENT VISION AND HEARING IMPAIRMENT IN OLDER ADULTS B. GOPINATH1, J. SCHNEIDER2, V.M. FLOOD3, C.M. MCMAHON4,5, G. BURLUTSKY1, S.R. LEEDER2, P. MITCHELL1 1. Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, NSW, Australia; 2. Menzies Centre for Health Policy, University of Sydney, Sydney, NSW, Australia; 3. Faculty of Health and Behavioural Sciences, University of Wollongong, Sydney, NSW, Australia; 4. HEARing Co-operative Research Centre, Australia; 5. Centre for Language Sciences, Linguistics Department, Macquarie University, Sydney, NSW, Australia. Corresponding author:Dr Bamini Gopinath, Centre for Vision Research, University of Sydney, Westmead Hospital, Hawkesbury Rd, Westmead, NSW, 2145, Australia. Telephone: 61 2 9845 5551 Fax: 61 2 9845 8345 Email: [email protected]
Abstract: Objectives: Published literature shows that individual nutrients could influence the risk of developing vision and hearing loss. There is, however, a lack of population-based data on the relationship between overall patterns of food intake and the presence of concurrent vision and hearing impairment. We aimed to assess the associations between diet quality with the prevalence and 5-year incidence of dual sensory impairment (DSI). Design: Cross-sectional and 5-year longitudinal analyses. Setting: Blue Mountains, Sydney, Australia. Participants: 2443 participants aged ≥50 from baseline were examined and followed over 5 years. Measurements: Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet score (TDS). Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average puretone air conduction threshold greater than 25 dB HL (500-4000 Hz, better ear). Results: After adjusting for age, sex, education, noise exposure, current smoking, and type 2 diabetes, participants in the lowest compared to the highest quintile of TDS had a 2-fold increased likelihood of having prevalent DSI, odds ratio, OR, 2.62 (95% confidence intervals, CI, 1.08-6.36), P-trend=0.04. Significant associations were not observed between TDS and the prevalence of having a single sensory impairment (vision or hearing loss). Baseline TDS was not significantly associated with the 5-year incidence of DSI. Adherence to dietary guidelines was associated with a reduced likelihood of having DSI in cross-sectional, but not in longitudinal analyses. Conclusions: Further studies with adequate power are warranted to assess the prospective relationship between diet quality and DSI. Key words: Blue Mountains Eye Study, diet quality, dual sensory impairment, hearing loss, vision loss.
indication of eating behaviors (13, 14). This approach groups foods a priori that are representative of current nutrition knowledge in the form of dietary guidelines or other dietary recommendations (15). Age-related macular degeneration (AMD) and cataract are the most important causes of vision loss in older people worldwide (16, 17). A US study of 479 women aged 52-73 years showed that women with higher versus lower healthy eating index (HEI) scores were less likely to have nuclear opacities (18). Recently, in another US study of 1808 women aged 40-79 years, the HEI score was inversely associated with prevalence of nuclear cataract (19). Similarly, a US study of 1313 participants aged 55-74 years demonstrated that women in the highest versus lowest quintile of the HEI had 46% lower odds of AMD (20). Our previous studies regarding the association between nutrition and age-related hearing loss have focused on individual nutrients or food groups (9, 21-23). For instance, we showed that high consumption of fish could reduce the risk of hearing loss (9), whereas high consumption of carbohydrates and a high-glycemic load diet are predictors of incident hearing loss among older adults (24). To our best knowledge, no study has examined the effects of overall diet quality on risk of hearing loss. There is also a lack of population-based data on the relation between adherence to dietary guidelines and the prevalence and incidence of DSI.
Introduction Impaired vision and hearing are common problems among aging populations (1, 2) and can occur separately or in combination (3). Individuals with combined vision and hearing loss, termed dual sensory impairment (DSI), are thought to experience more than the sum of each impairment alone (4, 5). Persons with DSI are shown to be more likely to experience depression, morbidity and functional limitations (4, 6-8). Given the multiple negative health impacts of DSI, it is imperative to identify modifiable risk factors and develop preventive strategies that could diminish the effect and burden of DSI on the global aging population (9). The existing published literature suggests that encouraging changes in the nutritional status of older adults could reduce the hearing and vision loss associated with increasing age. Studying individual nutrients or foods may provide an incomplete picture of the relationship between diet and sensory impairments, given that diets are usually consumed in combination of foods and the complex interactions between nutrients in our daily diets (10, 11). A healthy diet has been characterized in many ways; however, there is no consensus about what the best definition is (12). One frequently used approach is factor analysis or principal component analysis to derive dietary patterns from collected data providing an Received May 28, 2013 Accepted for publication July 24, 2013
1
J Nutr Health Aging
DIET QUALITY AND DUAL SENSORY IMPAIRMENT Improved population health with dietary guideline adherence will undoubtedly be beneficial to individuals at risk of concurrent vision and hearing impairment (25). In the present study, we aimed to investigate the relationship between overall diet quality, an assessment of how well an individual’s diet adhered to national dietary guidelines at baseline, with the prevalence and 5-year incidence of DSI in a large, representative sample of adults aged ≥50 years. Methods Study population The Blue Mountains Eye Study (BMES) is a populationbased cohort study of common eye diseases and other health outcomes in a suburban Australian population located west of Sydney. Study methods and procedures have been described elsewhere (26). Following a door-to-door census of the region, baseline examinations of 3654 residents aged >49 years were conducted during 1992-4 (BMES-1, 82.4% participation rate). Surviving baseline participants were invited to attend 5-year follow-up examinations (1997-9, BMES-2), at which 2334 (75.1% of survivors) and an additional 1174 newly eligible residents were examined. Hearing was measured at BMES-2 i.e. at BMES-2, 2956 participants had audiometric testing performed. At BMES-3 (2002-4), 1952 participants were reexamined. Visual acuity data were collected at all 3 BMES examinations; however, audiometric threshold data were collected only from BMES-2 (baseline hearing examination) and BMES-3. Therefore, only the 5-year incidence of DSI was analyzed in the current study. The study was approved by the Human Research Ethics Committee of the University of Sydney and was conducted adhering to the tenets of the Declaration of Helsinki. Signed informed consent was obtained from all the participants at each examination. Assessment of diet quality At baseline, dietary data were collected using a 145-item self-administered food frequency questionnaire (FFQ), modified for Australian diet and vernacular from an early Willett FFQ (27), and including reference portion sizes. Participants used a 9-category frequency scale to indicate the usual frequency of consuming individual food items during the past year. The FFQ was validated by comparing nutrients from the FFQ to 4-day weighed food records collected over one year (n=79). Most nutrient correlations were between 0.50 and 0.60 for energy-adjusted intakes, similar to other validated FFQ studies (28). A dietitian coded data from the FFQ into a customized database that incorporated the Australian Tables of Food Composition 1990 (NUTTAB 90) (29). A modified version of the Australian diet quality index (30), based on the Dietary Guidelines for Australian Adults (31) and the Australian Guide to Healthy Eating (AGHE) (32), was used to establish the Total Diet Score (TDS) assessing adherence to the Australian dietary guidelines. The methodology used to 2
develop TDS has been previously reported (33). Briefly, TDS were allocated for intakes of selected food groups and nutrients for each participant as described in the Dietary Guidelines for Australian Adults (details for FFQ food groupings available in online supplement 1). The TDS is divided into ten components, and each component has a possible score ranging from 0 to 2. A maximum score of 2 was given to subjects who met the recommendations with prorated scores for lower intakes (online supplement 1). These were then summated providing a final score ranging between 0 and 20 with higher scores indicating closer adherence to the dietary guidelines (33). The TDS account for both food intake and optimal choice with scores allocated to reflect intake characteristics from both sources. Food intake scores were based on total intakes of vegetables, fruit, cereals and breads, meat, fish, poultry and/or alternatives and dairy as well as sodium, alcohol, sugar and extra foods intakes. Optimal choices scores determined intakes of foods with greater dietary benefits including serves of whole grain cereals, lean red meat, low or reduced fat milk versus whole milk, low saturated fat intake and fish consumption. Cut points for scores were determined from recommended number of serves given in the AGHE with some exceptions (32). We replaced the AGHE’s recommended 2 serves per day of fruit with 3 serves per day and the number of vegetables consumed per day from five serves to seven serves to allow for selfreported FFQ overestimation as determined by the validity study (28). The alcohol cut-points reflect guidelines about alcohol consumption in Australia, in which it is recommended that men consume a maximum of 2 standard drinks per day and women 1 standard drink/ day (31). To follow dietary guideline recommendations as closely as possible, the non-dietary component of the AGHE, preventing weight gain, was included in the TDS. Half the score was assigned to energy balance, calculated as the ratio of energy intake to energy expenditure with a maximum score given for ratios falling between 0.76 and 1.24, defined as the 95% confidence levels of agreement between energy intake and expenditure (34). The other half of the score was assigned to leisure time physical activity. Details of walking exercise and the performance of moderate or vigorous activities were used to calculate metabolic equivalents (METs) (35). Subjects in the highest METs tertile scored 1 point reducing to a 0 point score for subjects in the lowest METs tertile (33). Audiological assessment Pure-tone audiometry at both visits was performed by audiologists in sound-treated booths, using TDH-39 earphones and Madsen OB822 audiometers (Madsen Electronics, Denmark). Sound-proof rooms were set-up according to International Standards Organization protocol 8253-2. Bilateral hearing impairment was determined as the pure-tone average of audiometric hearing thresholds at 500,1000, 2000, and 4000 Hz (PTA0.5-4kHz) in the better ear, defining any hearing loss as PTA0.5-4kHz > 25 dB HL; mild hearing loss as PTA0.5-4kHz
J Nutr Health Aging
THE JOURNAL OF NUTRITION, HEALTH & AGING© physician diagnosed acute myocardial infarction or angina. Presence of physician-diagnosed stroke was also assessed. History of diagnosed hypertension was defined as those who had previously diagnosed hypertension and were using antihypertensive medications, or had a systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥100 mm Hg at baseline examination. Diabetes was defined either by history or from fasting blood glucose ≥7.0 mmol/L. An audiologist administered questionnaires addressing hearing problems and noise exposure. This included: ‘Have you ever worked in a noisy industry or noisy farm environment?’ Occupational prestige was assessed from participant’s principal job using the Daniel Occupational Prestige Scale (36). Scores in our study population ranged from 1.4 to 6.7. We grouped subjects according to occupations that were less or more than 4.0 on the prestige scale (with 25-40 dB HL; and moderate to severe hearing loss as PTA0.5-4kHz >40 dB HL. Assessment of visual impairment Monocular distance logMAR (logarithm of the minimum angle of resolution) visual acuity was measured with forcedchoice procedures using the retroilluminated chart with automatic calibration to 85 cd/m2 (Vectorvision CSV-100TM; Vectorvision Inc, Dayton, Ohio) according to the Early Treatment Diabetic Retinopathy Study protocol (26). This was conducted with habitual correction (presenting visual acuity, with current eyeglasses, if worn) and after subjective refraction (best-corrected visual acuity). For each eye, visual acuity was recorded as the number of letters read correctly from 0 to 70. For the present study, any visual impairment was defined as presenting visual acuity of the better eye less than 39 letters (
THE JOURNAL OF NUTRITION, HEALTH & AGING©
ASSOCIATION BETWEEN DIET QUALITY WITH CONCURRENT VISION AND HEARING IMPAIRMENT IN OLDER ADULTS B. GOPINATH1, J. SCHNEIDER2, V.M. FLOOD3, C.M. MCMAHON4,5, G. BURLUTSKY1, S.R. LEEDER2, P. MITCHELL1 1. Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, NSW, Australia; 2. Menzies Centre for Health Policy, University of Sydney, Sydney, NSW, Australia; 3. Faculty of Health and Behavioural Sciences, University of Wollongong, Sydney, NSW, Australia; 4. HEARing Co-operative Research Centre, Australia; 5. Centre for Language Sciences, Linguistics Department, Macquarie University, Sydney, NSW, Australia. Corresponding author:Dr Bamini Gopinath, Centre for Vision Research, University of Sydney, Westmead Hospital, Hawkesbury Rd, Westmead, NSW, 2145, Australia. Telephone: 61 2 9845 5551 Fax: 61 2 9845 8345 Email: [email protected]
Abstract: Objectives: Published literature shows that individual nutrients could influence the risk of developing vision and hearing loss. There is, however, a lack of population-based data on the relationship between overall patterns of food intake and the presence of concurrent vision and hearing impairment. We aimed to assess the associations between diet quality with the prevalence and 5-year incidence of dual sensory impairment (DSI). Design: Cross-sectional and 5-year longitudinal analyses. Setting: Blue Mountains, Sydney, Australia. Participants: 2443 participants aged ≥50 from baseline were examined and followed over 5 years. Measurements: Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet score (TDS). Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average puretone air conduction threshold greater than 25 dB HL (500-4000 Hz, better ear). Results: After adjusting for age, sex, education, noise exposure, current smoking, and type 2 diabetes, participants in the lowest compared to the highest quintile of TDS had a 2-fold increased likelihood of having prevalent DSI, odds ratio, OR, 2.62 (95% confidence intervals, CI, 1.08-6.36), P-trend=0.04. Significant associations were not observed between TDS and the prevalence of having a single sensory impairment (vision or hearing loss). Baseline TDS was not significantly associated with the 5-year incidence of DSI. Adherence to dietary guidelines was associated with a reduced likelihood of having DSI in cross-sectional, but not in longitudinal analyses. Conclusions: Further studies with adequate power are warranted to assess the prospective relationship between diet quality and DSI. Key words: Blue Mountains Eye Study, diet quality, dual sensory impairment, hearing loss, vision loss.
indication of eating behaviors (13, 14). This approach groups foods a priori that are representative of current nutrition knowledge in the form of dietary guidelines or other dietary recommendations (15). Age-related macular degeneration (AMD) and cataract are the most important causes of vision loss in older people worldwide (16, 17). A US study of 479 women aged 52-73 years showed that women with higher versus lower healthy eating index (HEI) scores were less likely to have nuclear opacities (18). Recently, in another US study of 1808 women aged 40-79 years, the HEI score was inversely associated with prevalence of nuclear cataract (19). Similarly, a US study of 1313 participants aged 55-74 years demonstrated that women in the highest versus lowest quintile of the HEI had 46% lower odds of AMD (20). Our previous studies regarding the association between nutrition and age-related hearing loss have focused on individual nutrients or food groups (9, 21-23). For instance, we showed that high consumption of fish could reduce the risk of hearing loss (9), whereas high consumption of carbohydrates and a high-glycemic load diet are predictors of incident hearing loss among older adults (24). To our best knowledge, no study has examined the effects of overall diet quality on risk of hearing loss. There is also a lack of population-based data on the relation between adherence to dietary guidelines and the prevalence and incidence of DSI.
Introduction Impaired vision and hearing are common problems among aging populations (1, 2) and can occur separately or in combination (3). Individuals with combined vision and hearing loss, termed dual sensory impairment (DSI), are thought to experience more than the sum of each impairment alone (4, 5). Persons with DSI are shown to be more likely to experience depression, morbidity and functional limitations (4, 6-8). Given the multiple negative health impacts of DSI, it is imperative to identify modifiable risk factors and develop preventive strategies that could diminish the effect and burden of DSI on the global aging population (9). The existing published literature suggests that encouraging changes in the nutritional status of older adults could reduce the hearing and vision loss associated with increasing age. Studying individual nutrients or foods may provide an incomplete picture of the relationship between diet and sensory impairments, given that diets are usually consumed in combination of foods and the complex interactions between nutrients in our daily diets (10, 11). A healthy diet has been characterized in many ways; however, there is no consensus about what the best definition is (12). One frequently used approach is factor analysis or principal component analysis to derive dietary patterns from collected data providing an Received May 28, 2013 Accepted for publication July 24, 2013
1
J Nutr Health Aging
DIET QUALITY AND DUAL SENSORY IMPAIRMENT Improved population health with dietary guideline adherence will undoubtedly be beneficial to individuals at risk of concurrent vision and hearing impairment (25). In the present study, we aimed to investigate the relationship between overall diet quality, an assessment of how well an individual’s diet adhered to national dietary guidelines at baseline, with the prevalence and 5-year incidence of DSI in a large, representative sample of adults aged ≥50 years. Methods Study population The Blue Mountains Eye Study (BMES) is a populationbased cohort study of common eye diseases and other health outcomes in a suburban Australian population located west of Sydney. Study methods and procedures have been described elsewhere (26). Following a door-to-door census of the region, baseline examinations of 3654 residents aged >49 years were conducted during 1992-4 (BMES-1, 82.4% participation rate). Surviving baseline participants were invited to attend 5-year follow-up examinations (1997-9, BMES-2), at which 2334 (75.1% of survivors) and an additional 1174 newly eligible residents were examined. Hearing was measured at BMES-2 i.e. at BMES-2, 2956 participants had audiometric testing performed. At BMES-3 (2002-4), 1952 participants were reexamined. Visual acuity data were collected at all 3 BMES examinations; however, audiometric threshold data were collected only from BMES-2 (baseline hearing examination) and BMES-3. Therefore, only the 5-year incidence of DSI was analyzed in the current study. The study was approved by the Human Research Ethics Committee of the University of Sydney and was conducted adhering to the tenets of the Declaration of Helsinki. Signed informed consent was obtained from all the participants at each examination. Assessment of diet quality At baseline, dietary data were collected using a 145-item self-administered food frequency questionnaire (FFQ), modified for Australian diet and vernacular from an early Willett FFQ (27), and including reference portion sizes. Participants used a 9-category frequency scale to indicate the usual frequency of consuming individual food items during the past year. The FFQ was validated by comparing nutrients from the FFQ to 4-day weighed food records collected over one year (n=79). Most nutrient correlations were between 0.50 and 0.60 for energy-adjusted intakes, similar to other validated FFQ studies (28). A dietitian coded data from the FFQ into a customized database that incorporated the Australian Tables of Food Composition 1990 (NUTTAB 90) (29). A modified version of the Australian diet quality index (30), based on the Dietary Guidelines for Australian Adults (31) and the Australian Guide to Healthy Eating (AGHE) (32), was used to establish the Total Diet Score (TDS) assessing adherence to the Australian dietary guidelines. The methodology used to 2
develop TDS has been previously reported (33). Briefly, TDS were allocated for intakes of selected food groups and nutrients for each participant as described in the Dietary Guidelines for Australian Adults (details for FFQ food groupings available in online supplement 1). The TDS is divided into ten components, and each component has a possible score ranging from 0 to 2. A maximum score of 2 was given to subjects who met the recommendations with prorated scores for lower intakes (online supplement 1). These were then summated providing a final score ranging between 0 and 20 with higher scores indicating closer adherence to the dietary guidelines (33). The TDS account for both food intake and optimal choice with scores allocated to reflect intake characteristics from both sources. Food intake scores were based on total intakes of vegetables, fruit, cereals and breads, meat, fish, poultry and/or alternatives and dairy as well as sodium, alcohol, sugar and extra foods intakes. Optimal choices scores determined intakes of foods with greater dietary benefits including serves of whole grain cereals, lean red meat, low or reduced fat milk versus whole milk, low saturated fat intake and fish consumption. Cut points for scores were determined from recommended number of serves given in the AGHE with some exceptions (32). We replaced the AGHE’s recommended 2 serves per day of fruit with 3 serves per day and the number of vegetables consumed per day from five serves to seven serves to allow for selfreported FFQ overestimation as determined by the validity study (28). The alcohol cut-points reflect guidelines about alcohol consumption in Australia, in which it is recommended that men consume a maximum of 2 standard drinks per day and women 1 standard drink/ day (31). To follow dietary guideline recommendations as closely as possible, the non-dietary component of the AGHE, preventing weight gain, was included in the TDS. Half the score was assigned to energy balance, calculated as the ratio of energy intake to energy expenditure with a maximum score given for ratios falling between 0.76 and 1.24, defined as the 95% confidence levels of agreement between energy intake and expenditure (34). The other half of the score was assigned to leisure time physical activity. Details of walking exercise and the performance of moderate or vigorous activities were used to calculate metabolic equivalents (METs) (35). Subjects in the highest METs tertile scored 1 point reducing to a 0 point score for subjects in the lowest METs tertile (33). Audiological assessment Pure-tone audiometry at both visits was performed by audiologists in sound-treated booths, using TDH-39 earphones and Madsen OB822 audiometers (Madsen Electronics, Denmark). Sound-proof rooms were set-up according to International Standards Organization protocol 8253-2. Bilateral hearing impairment was determined as the pure-tone average of audiometric hearing thresholds at 500,1000, 2000, and 4000 Hz (PTA0.5-4kHz) in the better ear, defining any hearing loss as PTA0.5-4kHz > 25 dB HL; mild hearing loss as PTA0.5-4kHz
J Nutr Health Aging
THE JOURNAL OF NUTRITION, HEALTH & AGING© physician diagnosed acute myocardial infarction or angina. Presence of physician-diagnosed stroke was also assessed. History of diagnosed hypertension was defined as those who had previously diagnosed hypertension and were using antihypertensive medications, or had a systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥100 mm Hg at baseline examination. Diabetes was defined either by history or from fasting blood glucose ≥7.0 mmol/L. An audiologist administered questionnaires addressing hearing problems and noise exposure. This included: ‘Have you ever worked in a noisy industry or noisy farm environment?’ Occupational prestige was assessed from participant’s principal job using the Daniel Occupational Prestige Scale (36). Scores in our study population ranged from 1.4 to 6.7. We grouped subjects according to occupations that were less or more than 4.0 on the prestige scale (with 25-40 dB HL; and moderate to severe hearing loss as PTA0.5-4kHz >40 dB HL. Assessment of visual impairment Monocular distance logMAR (logarithm of the minimum angle of resolution) visual acuity was measured with forcedchoice procedures using the retroilluminated chart with automatic calibration to 85 cd/m2 (Vectorvision CSV-100TM; Vectorvision Inc, Dayton, Ohio) according to the Early Treatment Diabetic Retinopathy Study protocol (26). This was conducted with habitual correction (presenting visual acuity, with current eyeglasses, if worn) and after subjective refraction (best-corrected visual acuity). For each eye, visual acuity was recorded as the number of letters read correctly from 0 to 70. For the present study, any visual impairment was defined as presenting visual acuity of the better eye less than 39 letters (
