Current status of body mass index and related influencing factors in the elderly aged 65 years and older in 8 longevity areas in China

Objective: To understand the current status of BMI of the elderly and related factors in longevity areas in China, and provide scientific evidence for the control of BMI level in elderly population. Methods: Data used in this study were obtained from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey. A total of 2 825 elderly in 8 longevity areas in China were surveyed and measured in 2017. The BMI levels of 2 217 elderly aged 65 years and older were calculated and in follow up. The ordered classification logistic regression model was used to analyze the influencd factors for the BMI in the elderly. Results: The BMI of the elderly in 8 longevity areas in China was (22.36+/-3.87) kg/m(2), and it was (22.76+/-3.58) kg/m(2) for males and (21.75+/-3.98) kg/m(2) for females. The BMI levels were normal in 1 165 elderly persons. The prevalence of underweight, overweight and obesity were 15.8%, 24.0% and 7.7%, respectively. Multivariate analysis showed that the main factors affecting the BMI of people under 100- years old were age (65-: OR=2.78, 95%CI: 1.87-4.15; 80-: OR=1.47, 95%CI: 1.00-2.17), smoking status (OR=0.46, 95%CI: 0.32-0.66), annual household income ( /=100 years was gender (OR=3.68, 95%CI: 1.32-10.36). Conclusions: The prevalence of underweight, overweight and obesity were high in the elderly from longevity areas in China. It is necessary to pay attention to the trend of overweight and obesity due to smoking, higher annual household income and regular tea drinking in the elderly men.