Background: The occurrence of diabetes has greatly increased in low- and middle-income countries, particularly in Asia, as has the prevalence of overweight and obesity; in European-derived populations, overweight and obesity are established causes of diabetes. The shape of the association of overweight and obesity with diabetes risk and its overall impact have not been adequately studied in Asia.
Methods and Findings: A pooled cross-sectional analysis was conducted to evaluate the association between baseline body mass index (BMI, measured as weight in kg divided by the square of height in m) and self-reported diabetes status in over 900,000 individuals recruited in 18 cohorts from Bangladesh, China, India, Japan, Korea, Singapore and Taiwan. Logistic regression models were fitted to calculate cohort-specific odds ratios (OR) of diabetes for categories of increasing BMI, after adjustment for potential confounding factors. OR were pooled across cohorts using a random-effects meta-analysis. The sex- and age-adjusted prevalence of diabetes was 4.3% in the overall population, ranging from 0.5% to 8.2% across participating cohorts. Using the category 22.5–24.9 Kg/m2 as reference, the OR for diabetes spanned from 0.58 (95% confidence interval [CI] 0.31, 0.76) for BMI lower than 15.0 kg/m2 to 2.23 (95% CI 1.86, 2.67) for BMI higher than 34.9 kg/m2. The positive association between BMI and diabetes prevalence was present in all cohorts and in all subgroups of the study population, although the association was stronger in individuals below age 50 at baseline (p-value of interaction<0.001), in cohorts from India and Bangladesh (p<0.001), in individuals with low education (p-value 0.02), and in smokers (p-value 0.03); no differences were observed by gender, urban residence, or alcohol drinking.
Conclusions: This study estimated the shape and the strength of the association between BMI and prevalence of diabetes in Asian populations and identified patterns of the association by age, country, and other risk factors for diabetes.
Funding Information
3-Prefecture Aichi
3-Prefecture Miyagi, Grant in-aid for Cancer Research
3-Prefecture Miyagi, Grant for the Third Term Comprehensive Control Research for Cancer
3-Prefecture Miyagi, Grant for Health Services
3-Prefecture Miyagi, Grant for Medical Services for Aged and Health Promotion
Ministry of Health, Labour and Welfare, Japan, Grant for Comprehensive Research on Cardiovascular and Life-Style Related Diseases
Ministry of Education, Culture, Sports, Science and Technology, Japan, Grant for the Scientific Research
American Heart Association, China National Hypertension Survey Epidemiology Follow-up Study, 9750612N
National Heart, Lung and Blood Institute, U01 HL072507
National Institutes for Health, Chinese Academy of Medical Sciences Shanghai Cohort Study, R01CA0403092
National Institutes for Health, Chinese Academy of Medical Sciences Shanghai Cohort Study, R01CA144034
National Institutes for Health, Shanghai Men's Health Study, RO1 CA 82729
National Institutes for Health, Shanghai Women's Health Study, R37CA70867
National Science Council and Department of Health, Taiwan, The Community-Based Cancer Screening Project
Department of Health, Taiwan, Disease risk FACtor Two-township Study, DOH80-27
Department of Health, Taiwan, Disease risk FACtor Two-township Study, DOH81-021
Department of Health, Taiwan, Disease risk FACtor Two-township Study, DOH8202-1027
Department of Health, Taiwan, Disease risk FACtor Two-township Study, DOH83-TD-015
Department of Health, Taiwan, Disease risk FACtor Two-township Study, DOH84-TD-006
Ministry of Education, Science and Technology, Korea, The Korea Multi-center Cancer Cohort, 2009-0087452
National Research Foundation of Korea, 2009-0087452
National Institutes of Health, The Singapore Chinese Health Study, R01CA55069
National Institutes of Health, The Singapore Chinese Health Study, R35CA53890
National Institutes of Health, The Singapore Chinese Health Study, R01CA80205
National Institutes of Health, The Singapore Chinese Health Study, R01CA144034
National Institutes of Health, Health Effects of Arsenic Longitudinal Study, P42ES010349
National Institutes of Health, Health Effects of Arsenic Longitudinal Study, R01CA102484
National Institutes of Health, Health Effects of Arsenic Longitudinal Study, R01CA107431
International Agency for Research on Cancer, Lyon, France, The Mumbai Cohort Study
Clinical Trials Service Unit, Oxford, U.K
World Health Organisation