Yao He1, Tai Hing Lam2, Bin Jiang3, Lan Sun Li4, Dong Ling Sun5, Lei Wu6, Miao Liu6, Shan Shan Yang6, Yi Yan Wang6, Deirdre K Tobias7, Qi Sun7, Frank B Hu8. 1. Institute of Geriatrics, Chinese PLA General Hospital, Beijing, China State Key Laboratory of Kidney Disease, Chinese PLA General Hospital, Beijing, China Beijing Key Laboratory of Aging and Geriatrics, Chinese PLA General Hospital, Beijing, China yhe301@x263.net frank.hu@channing.harvard.edu. 2. School of Public Health and Department of Community Medicine, The University of Hong Kong, Hong Kong, China. 3. Department of Chinese Traditional Medicine and Acupuncture, Chinese PLA General Hospital, Beijing, China. 4. Department of Cardiology, Fourth Military Medical University, Xi'an, China. 5. Institute of Geriatrics, Chinese PLA General Hospital, Beijing, China. 6. Institute of Geriatrics, Chinese PLA General Hospital, Beijing, China Beijing Key Laboratory of Aging and Geriatrics, Chinese PLA General Hospital, Beijing, China. 7. Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA. 8. Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA yhe301@x263.net frank.hu@channing.harvard.edu.
Abstract
OBJECTIVE: It is unclear whether changes in BMI during rapid economic development influence subsequent mortality. RESEARCH DESIGN AND METHODS: We analyzed whether BMI in 1976 and 1994 and changes in BMI during 1976-1994 predict cardiovascular disease (CVD) and all-cause mortality in a 35-year follow-up cohort of 1,696 Chinese (1,124 men and 572 women, aged 35-65 years) in Xi'an, China. Participants were categorized as underweight (<18.5 kg/m(2)), normal weight (18.5-24.9 kg/m(2)), and overweight (≥25.0 kg/m(2)). RESULTS: During 51,611 person-years of follow-up, we identified 655 deaths from all causes and 234 from CVD. From 1976 to 1994, the prevalence of overweight rose from 9.2 to 27.8%. With each unit increment in 1976 BMI, multivariate hazard ratios (HRs) (95% CI) were 0.78 (0.72-0.84) for CVD and 0.91 (0.87-0.95) for all-cause mortality. In contrast, corresponding HRs were 1.14 (1.08-1.19) and 1.05 (1.01-1.08) in 1994 BMI. The HRs for each unit increment in BMI change from 1976 to 1994 were 1.35 (1.25-1.41) for CVD and 1.09 (1.05-1.13) for all-cause mortality. Compared with participants with stable normal weight in 1976 and 1994, HRs of all-cause mortality for those who had normal weight in 1976 but became overweight in 1994 and for those who were persistently overweight during 1976-1994 were 1.42 (1.12-1.80) and 1.80 (1.04-3.14), respectively. CONCLUSIONS: Gaining weight with increased BMI at middle age in Chinese during economic development was associated with elevated risks of all-cause and CVD mortality. Higher BMI measured before economic development was associated with lower mortality risk, whereas BMI measured afterward was associated with increased mortality.
OBJECTIVE: It is unclear whether changes in BMI during rapid economic development influence subsequent mortality. RESEARCH DESIGN AND METHODS: We analyzed whether BMI in 1976 and 1994 and changes in BMI during 1976-1994 predict cardiovascular disease (CVD) and all-cause mortality in a 35-year follow-up cohort of 1,696 Chinese (1,124 men and 572 women, aged 35-65 years) in Xi'an, China. Participants were categorized as underweight (<18.5 kg/m(2)), normal weight (18.5-24.9 kg/m(2)), and overweight (≥25.0 kg/m(2)). RESULTS: During 51,611 person-years of follow-up, we identified 655 deaths from all causes and 234 from CVD. From 1976 to 1994, the prevalence of overweight rose from 9.2 to 27.8%. With each unit increment in 1976 BMI, multivariate hazard ratios (HRs) (95% CI) were 0.78 (0.72-0.84) for CVD and 0.91 (0.87-0.95) for all-cause mortality. In contrast, corresponding HRs were 1.14 (1.08-1.19) and 1.05 (1.01-1.08) in 1994 BMI. The HRs for each unit increment in BMI change from 1976 to 1994 were 1.35 (1.25-1.41) for CVD and 1.09 (1.05-1.13) for all-cause mortality. Compared with participants with stable normal weight in 1976 and 1994, HRs of all-cause mortality for those who had normal weight in 1976 but became overweight in 1994 and for those who were persistently overweight during 1976-1994 were 1.42 (1.12-1.80) and 1.80 (1.04-3.14), respectively. CONCLUSIONS: Gaining weight with increased BMI at middle age in Chinese during economic development was associated with elevated risks of all-cause and CVD mortality. Higher BMI measured before economic development was associated with lower mortality risk, whereas BMI measured afterward was associated with increased mortality.