Obesity Research & Clinical Practice (2010) 4, e15—e23
ORIGINAL ARTICLE
Gender and age differences in the impact of overweight on obesity-related quality of life among Korean adults H.R. Song a, H.S. Park b,∗, K.E. Yun b, S.H. Cho c, E.Y. Choi d, S.Y. Lee e, J.H. Kim f, H.N. Sung f, J.H. Kim g, S.I. Choi h, Y.S. Yoon a, E.S. Lee a, J.H. Han i, C.I. Shin j, H.M. Chang k, S.C. Bae l a
Department of Family Medicine, Eulji University Hospital, South Korea University of Ulsan College of Medicine, South Korea c College of Medicine, Chung-ang University, South Korea d Dankook University School of Medicine, South Korea e Pusan National University School of Medicine and Medical Research Institute, South Korea f College of Medicine, Korea University, South Korea g Hana General Hospital, South Korea h Yonsei University College of Medicine, South Korea i College of Medicine, Eulji University, South Korea j College of Medicine, Kyunhee University, South Korea k Hallym University, South Korea l Department of Internal Medicine, Hanyang University College of Medicine, South Korea b
Received 8 August 2008 ; received in revised form 17 July 2009; accepted 21 July 2009
KEYWORDS Obesity-related QOL; Overweight; Gender; Age
Summary Objective: To investigate gender and age difference in impact of overweight on health-related quality of life (HRQOL) among Korean adults. Methods: Cross-sectional obesity-related quality of life (QOL) scores were measured by a Korean obesity-related QOL scale (KOQOL) from 448 Korean adults aged 20—80 years. A body mass index (BMI) was categorized with normal-weight as BMI < 23 kg/m2 , overweight as BMI ≥ 23 kg/m2 based on the alternative cutoff points for Asians. Each gender was respectively stratified by median age, 45 years for men and 50 years for women, to examine the obesity-related QOL by age groups. Results: Women had a poorer obesity-related QOL compared to men (p < 0.001). In the younger age group, overweight women had a poorer obesity-related QOL compared with normal-weight women (p < 0.001), however normal-weight and overweight men showed no difference in obesity-related QOL. In the older age group,
∗ Corresponding author at: Department of Family Medicine, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea. Tel.: +82 2 3010 3813; fax: +82 2 3010 3815. E-mail address: [email protected] (H.S. Park).
1871-403X/$ — see front matter © 2009 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.orcp.2009.07.003
e16
H.R. Song et al. overweight men showed better QOL on the domains of work-related and psychosocial health than those for normal-weight men, but overweight women still suffered from work-related and routine life QOL. Conclusions: This study showed the impact of overweight on obesity-related QOL was different for gender and age group. We should consider the results to manage weight in overweight persons. © 2009 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Introduction Overweight and obesity is a major public health concern not only in western countries but also in Asian countries because of the increasing prevalence and the associated morbidity and mortality [1—3]. The prevalence of obesity (body mass index (BMI) ≥ 30 kg/m2 ) in the US was 32.2% in 2004 [4]. While the prevalence of obesity in Asian populations is lower than that of Caucasians, the health risks associated with obesity occur at a lower body mass index (BMI). Accordingly, the criteria of overweight and obesity in the Asian-Pacific region of WHO have been proposed as BMI ≥ 23 kg/m2 and BMI ≥ 25 kg/m2 , respectively [5]. The prevalence of obesity using a BMI ≥ 25 kg/m2 among Koreans was 34.9% in 2005 [6] which represented a rapid increase compared to 1998 [7]. The effect of being obesity or overweight and how it decreases health-related quality of life (HRQOL) has been well documented [8—13]. Increased BMI was most prominently associated with body pain [8]. Weight loss in overweight is desirable and likely to be beneficial for physical function, vitality, and body pain [9]. Obesity and overweight in adulthood is associated with large decreases in life expectancy [10]. Obese can expect 7.2 years less of quality-adjusted life expectancy over their remaining lifetime [11]. For a given body weight, some individuals are uncomfortable or less motivated to lose weight: others are sensitive to obesity-related health problems and eager to lose weight although not severely obese. How overweight individuals score on the HRQOL may differ according to individual characteristics. Some studies have shown ethnicity to influence how overweight individuals score on HRQOL [14]. A recent study suggested that lowered threshold for defining overweight is needed to identify patients who are more likely to have clinically significant reductions in HRQOL and functional impairment [12]. There were also significant gender differences, with women showing greater impact of weight on self-esteem and sexual life compared
with men. The impact of age was a bit surprising, with some areas showing positive changes and others showing no change [13]. Because Asian people are susceptible to health problems at lower BMI levels compared to western people, we tried to compare obesity-related QOL between overweight (BMI ≥ 23 kg/m2 ) and normal-weight (BMI < 23 kg/m2 ) individuals and to investigate how gender and age differences affect overweight Korean adults in obesity-related QOL.
Methods Study subjects A cross-sectional, hospital-based study was performed on 448 Korean adults, aged 20—80 years, who had visited for regular health examinations or the management of chronic diseases at the Department of Family Medicine or Health Promotion Centers of 12 hospitals located in Seoul and Gyeonggi Province, Korea during the period of March—July 2007. Subjects were excluded if they had secondary obesity, advanced malignancy, severe debilitating diseases, psychiatric diseases, pregnant, or lactating. Subjects with a history of intentional weight loss in the preceding 6 months of the current study or treatment with any antiobesity agents were also excluded. The study was approved by the Institutional Review Board of Asan Medical Center and all participants signed informed consent forms.
Anthropometric measurements and basic questionnaires Body weight and height were measured while the subjects were wearing light clothing without shoes by trained research personnel. Body mass index (BMI) was calculated as the weight in kg divided by height in m2 . Waist circumference (WC) measurements were taken from the midlevel between the lower extent of the rib cage and the iliac
Gender and age differences in the impact of overweight on obesity-related quality of life
e17
Table 1 Questionnaires of Korean obesity-related Quality of Life (KOQOL) scale. These questions ask about how √ you have been feeling in the last month. Answer every question with a tick ( ) to indicate your response. Never (1)
Sometimes (2)
Often (3)
Always (4)
Psychological health 1. I feel myself inferior to others. 2. I do not like to meet with other people. 3. I feel I do not look good. 4. I feel depressed.
Physical health 5. I am afraid of possible complications. 6. I have pain on my knee or ankle. 7. I have shortness of breath when I work out.
Work-related 8. I get lazy and fatigued. 9. I am less effective on my work performance. 10. It is hard to work when I crouch.
Routine life 11. I have difficulty when I take stairway. 12. It is hard to find big enough well-fitting clothes.
Sexual life 13. I think I am not sexually attractive. 14. I am afraid of having sexual relationship.
Diet-distress 15. I feel concern about weight-gain whenever I eat.
Score
NA
Total score NA, not available.
crest. BMI was categorized with normal-weight as BMI < 23 kg/m2 , overweight as BMI ≥ 23 kg/m2 based on the cutoff points for Asians [5,15,16]. The data on socio-demographic and lifestyle factors were collected using self-administered questionnaires. They included variables on age, marital status, occupation, education, income, smoking status, alcohol intake, and exercise.
Obesity-related QOL measurements We used Korean obesity-related QOL scale (KOQOL) as a measurement tool for obesity-related QOL among study participants. The KOQOL was developed to measure obesity-related QOL for Koreans with established verification of the reliability and validity [17]. The KOQOL was a self-administered instrument composed of 15 items and classified 6 domains which include: psychosocial health (4 items), physical health (3 items), work-related (3 items), routine life (2 items), sexual life (2 items), and diet-distress (1 item). These subscales are scored separately on a range from 1 (highest level of QOL) to 4 (lowest level of QOL), with higher scores
representing worse obesity-related QOL. The scores of each domain were calculated by the sum of the composites (Table 1).
Statistical analysis All descriptive statistical results are presented as mean ± SEM for continuous variables or numbers (%) for categorical variables. Comparisons of socio-demographics, lifestyle factors, and obesityrelated variables between genders were performed by unpaired t-test for continuous variables and by 2 -test for categorical variables. Comparisons of the obesity-related QOL between normal-weight and overweight subjects for each gender were calculated by ANCOVA to adjust for age, lifestyle factors and all socio-demographic variables. Each gender was stratified by median age, 45 years for men and 50 years for women, to examine the obesity-related QOL by age groups. ANCOVA was performed to compare the obesity-related QOL between normal-weight and overweight subjects of each age group for both genders after adjusting for age, socio-demographic, and lifestyle factors. All
e18
H.R. Song et al.
analyses were performed using SPSS version 12.0. A two-tailed p-value < 0.05 was considered significant.
cise was significantly higher in men than those in women. However, the mean obesity-related QOL score for women (28.33 ± 6.44) was significantly higher (poorer QOL) than those for men (24.42 ± 5.31) (p < 0.001).
Results Characteristics of the study subjects The characteristics of the study subjects are presented in Table 2. The mean BMI was 25.40 ± 3.17 kg/m2 for men and 24.17 ± 3.27 kg/m2 for women. The BMI and WC were significantly higher in men than those in women. The percentage of marriage, white collar, higher education, higher income, smoking, alcohol drinking, and exer-
Table 2
Comparisons of the obesity-related QOL between normal-weight and overweight in men and women Tables 3 and 4 show the KOQOL scores according to overweight for each gender. The total KOQOL scores for overweight subjects were not different from those with normal-weight subjects for men. Furthermore, the overweight men had lower scores (better QOL) in the domain of psy-
Baseline characteristics of study subjects. Mean ± SEM or number (%) of participants
Age (y) BMI (kg/m2 ) WC (cm) Total KOQOL score
Men (n = 272)
Women (n = 176)
Mean ± SEM
Mean ± SEM
p-Valuea
46.31 ± 0.62 25.40 ± 0.18 88.51 ± 0.48 24.42 ± 0.32
49.21 ± 0.95 24.17 ± 0.25 81.02 ± 0.66 28.33 ± 0.48
0.011
ORIGINAL ARTICLE
Gender and age differences in the impact of overweight on obesity-related quality of life among Korean adults H.R. Song a, H.S. Park b,∗, K.E. Yun b, S.H. Cho c, E.Y. Choi d, S.Y. Lee e, J.H. Kim f, H.N. Sung f, J.H. Kim g, S.I. Choi h, Y.S. Yoon a, E.S. Lee a, J.H. Han i, C.I. Shin j, H.M. Chang k, S.C. Bae l a
Department of Family Medicine, Eulji University Hospital, South Korea University of Ulsan College of Medicine, South Korea c College of Medicine, Chung-ang University, South Korea d Dankook University School of Medicine, South Korea e Pusan National University School of Medicine and Medical Research Institute, South Korea f College of Medicine, Korea University, South Korea g Hana General Hospital, South Korea h Yonsei University College of Medicine, South Korea i College of Medicine, Eulji University, South Korea j College of Medicine, Kyunhee University, South Korea k Hallym University, South Korea l Department of Internal Medicine, Hanyang University College of Medicine, South Korea b
Received 8 August 2008 ; received in revised form 17 July 2009; accepted 21 July 2009
KEYWORDS Obesity-related QOL; Overweight; Gender; Age
Summary Objective: To investigate gender and age difference in impact of overweight on health-related quality of life (HRQOL) among Korean adults. Methods: Cross-sectional obesity-related quality of life (QOL) scores were measured by a Korean obesity-related QOL scale (KOQOL) from 448 Korean adults aged 20—80 years. A body mass index (BMI) was categorized with normal-weight as BMI < 23 kg/m2 , overweight as BMI ≥ 23 kg/m2 based on the alternative cutoff points for Asians. Each gender was respectively stratified by median age, 45 years for men and 50 years for women, to examine the obesity-related QOL by age groups. Results: Women had a poorer obesity-related QOL compared to men (p < 0.001). In the younger age group, overweight women had a poorer obesity-related QOL compared with normal-weight women (p < 0.001), however normal-weight and overweight men showed no difference in obesity-related QOL. In the older age group,
∗ Corresponding author at: Department of Family Medicine, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea. Tel.: +82 2 3010 3813; fax: +82 2 3010 3815. E-mail address: [email protected] (H.S. Park).
1871-403X/$ — see front matter © 2009 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.orcp.2009.07.003
e16
H.R. Song et al. overweight men showed better QOL on the domains of work-related and psychosocial health than those for normal-weight men, but overweight women still suffered from work-related and routine life QOL. Conclusions: This study showed the impact of overweight on obesity-related QOL was different for gender and age group. We should consider the results to manage weight in overweight persons. © 2009 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Introduction Overweight and obesity is a major public health concern not only in western countries but also in Asian countries because of the increasing prevalence and the associated morbidity and mortality [1—3]. The prevalence of obesity (body mass index (BMI) ≥ 30 kg/m2 ) in the US was 32.2% in 2004 [4]. While the prevalence of obesity in Asian populations is lower than that of Caucasians, the health risks associated with obesity occur at a lower body mass index (BMI). Accordingly, the criteria of overweight and obesity in the Asian-Pacific region of WHO have been proposed as BMI ≥ 23 kg/m2 and BMI ≥ 25 kg/m2 , respectively [5]. The prevalence of obesity using a BMI ≥ 25 kg/m2 among Koreans was 34.9% in 2005 [6] which represented a rapid increase compared to 1998 [7]. The effect of being obesity or overweight and how it decreases health-related quality of life (HRQOL) has been well documented [8—13]. Increased BMI was most prominently associated with body pain [8]. Weight loss in overweight is desirable and likely to be beneficial for physical function, vitality, and body pain [9]. Obesity and overweight in adulthood is associated with large decreases in life expectancy [10]. Obese can expect 7.2 years less of quality-adjusted life expectancy over their remaining lifetime [11]. For a given body weight, some individuals are uncomfortable or less motivated to lose weight: others are sensitive to obesity-related health problems and eager to lose weight although not severely obese. How overweight individuals score on the HRQOL may differ according to individual characteristics. Some studies have shown ethnicity to influence how overweight individuals score on HRQOL [14]. A recent study suggested that lowered threshold for defining overweight is needed to identify patients who are more likely to have clinically significant reductions in HRQOL and functional impairment [12]. There were also significant gender differences, with women showing greater impact of weight on self-esteem and sexual life compared
with men. The impact of age was a bit surprising, with some areas showing positive changes and others showing no change [13]. Because Asian people are susceptible to health problems at lower BMI levels compared to western people, we tried to compare obesity-related QOL between overweight (BMI ≥ 23 kg/m2 ) and normal-weight (BMI < 23 kg/m2 ) individuals and to investigate how gender and age differences affect overweight Korean adults in obesity-related QOL.
Methods Study subjects A cross-sectional, hospital-based study was performed on 448 Korean adults, aged 20—80 years, who had visited for regular health examinations or the management of chronic diseases at the Department of Family Medicine or Health Promotion Centers of 12 hospitals located in Seoul and Gyeonggi Province, Korea during the period of March—July 2007. Subjects were excluded if they had secondary obesity, advanced malignancy, severe debilitating diseases, psychiatric diseases, pregnant, or lactating. Subjects with a history of intentional weight loss in the preceding 6 months of the current study or treatment with any antiobesity agents were also excluded. The study was approved by the Institutional Review Board of Asan Medical Center and all participants signed informed consent forms.
Anthropometric measurements and basic questionnaires Body weight and height were measured while the subjects were wearing light clothing without shoes by trained research personnel. Body mass index (BMI) was calculated as the weight in kg divided by height in m2 . Waist circumference (WC) measurements were taken from the midlevel between the lower extent of the rib cage and the iliac
Gender and age differences in the impact of overweight on obesity-related quality of life
e17
Table 1 Questionnaires of Korean obesity-related Quality of Life (KOQOL) scale. These questions ask about how √ you have been feeling in the last month. Answer every question with a tick ( ) to indicate your response. Never (1)
Sometimes (2)
Often (3)
Always (4)
Psychological health 1. I feel myself inferior to others. 2. I do not like to meet with other people. 3. I feel I do not look good. 4. I feel depressed.
Physical health 5. I am afraid of possible complications. 6. I have pain on my knee or ankle. 7. I have shortness of breath when I work out.
Work-related 8. I get lazy and fatigued. 9. I am less effective on my work performance. 10. It is hard to work when I crouch.
Routine life 11. I have difficulty when I take stairway. 12. It is hard to find big enough well-fitting clothes.
Sexual life 13. I think I am not sexually attractive. 14. I am afraid of having sexual relationship.
Diet-distress 15. I feel concern about weight-gain whenever I eat.
Score
NA
Total score NA, not available.
crest. BMI was categorized with normal-weight as BMI < 23 kg/m2 , overweight as BMI ≥ 23 kg/m2 based on the cutoff points for Asians [5,15,16]. The data on socio-demographic and lifestyle factors were collected using self-administered questionnaires. They included variables on age, marital status, occupation, education, income, smoking status, alcohol intake, and exercise.
Obesity-related QOL measurements We used Korean obesity-related QOL scale (KOQOL) as a measurement tool for obesity-related QOL among study participants. The KOQOL was developed to measure obesity-related QOL for Koreans with established verification of the reliability and validity [17]. The KOQOL was a self-administered instrument composed of 15 items and classified 6 domains which include: psychosocial health (4 items), physical health (3 items), work-related (3 items), routine life (2 items), sexual life (2 items), and diet-distress (1 item). These subscales are scored separately on a range from 1 (highest level of QOL) to 4 (lowest level of QOL), with higher scores
representing worse obesity-related QOL. The scores of each domain were calculated by the sum of the composites (Table 1).
Statistical analysis All descriptive statistical results are presented as mean ± SEM for continuous variables or numbers (%) for categorical variables. Comparisons of socio-demographics, lifestyle factors, and obesityrelated variables between genders were performed by unpaired t-test for continuous variables and by 2 -test for categorical variables. Comparisons of the obesity-related QOL between normal-weight and overweight subjects for each gender were calculated by ANCOVA to adjust for age, lifestyle factors and all socio-demographic variables. Each gender was stratified by median age, 45 years for men and 50 years for women, to examine the obesity-related QOL by age groups. ANCOVA was performed to compare the obesity-related QOL between normal-weight and overweight subjects of each age group for both genders after adjusting for age, socio-demographic, and lifestyle factors. All
e18
H.R. Song et al.
analyses were performed using SPSS version 12.0. A two-tailed p-value < 0.05 was considered significant.
cise was significantly higher in men than those in women. However, the mean obesity-related QOL score for women (28.33 ± 6.44) was significantly higher (poorer QOL) than those for men (24.42 ± 5.31) (p < 0.001).
Results Characteristics of the study subjects The characteristics of the study subjects are presented in Table 2. The mean BMI was 25.40 ± 3.17 kg/m2 for men and 24.17 ± 3.27 kg/m2 for women. The BMI and WC were significantly higher in men than those in women. The percentage of marriage, white collar, higher education, higher income, smoking, alcohol drinking, and exer-
Table 2
Comparisons of the obesity-related QOL between normal-weight and overweight in men and women Tables 3 and 4 show the KOQOL scores according to overweight for each gender. The total KOQOL scores for overweight subjects were not different from those with normal-weight subjects for men. Furthermore, the overweight men had lower scores (better QOL) in the domain of psy-
Baseline characteristics of study subjects. Mean ± SEM or number (%) of participants
Age (y) BMI (kg/m2 ) WC (cm) Total KOQOL score
Men (n = 272)
Women (n = 176)
Mean ± SEM
Mean ± SEM
p-Valuea
46.31 ± 0.62 25.40 ± 0.18 88.51 ± 0.48 24.42 ± 0.32
49.21 ± 0.95 24.17 ± 0.25 81.02 ± 0.66 28.33 ± 0.48
0.011
