[Association between a body shape index and all-cause mortality in the elderly in communities of Beijing]

Objective: To describe and analyze the distribution characteristics of a body shape index (ABSI) and its association with all-cause mortality in the elderly in communities of Beijing. Methods: The baseline and follow-up data of 10 423 subjects in Beijing Healthy Aging Cohort Study were used. The endpoint outcome was all-cause mortality in follow-up. The associations of ABSI, BMI and waist circumference with all-cause mortality were analyzed with a Cox proportional hazard regression model. Results: The mean follow-up time in this cohort was 6.36 years and the all-cause mortality was 15.27%. The restricted cubic spline results showed that ABSI showed a "U" association with all-cause mortality in the total population. After adjustment for confounding factors, compared with the normal ABSI group, the risk for all-cause mortality was higher in the low ABSI group (HR=1.69, 95%CI: 1.32-2.17) and high ABSI group (HR=1.75, 95%CI: 1.40-2.18). Compared with the normal BMI group, low BMI was associated with an increased risk for all-cause mortality (HR=1.70, 95%CI: 1.40-2.08). Compared with the normal waist circumference group, central obesity was associated with a decreased risk for all-cause mortality (HR=0.89, 95%CI: 0.80-0.99). The results of gender specific analysis on ABSI association with all-cause mortality were similar to that in total population, but the strength of association varied among different age groups. Cross-grouping results showed that older people with normal BMI and waist circumference and abnormal ABSI had an increased risk of all-cause mortality (HR=1.91, 95%CI: 1.22-2.99). Conclusions: In Beijing, ABSI is correlated with the risk for all-cause mortality in the elderly population, which is more sensitive and specific than the traditional indicators (BMI and waist circumference). They can be used as one of the physical measurement indicators for all-cause mortality risk prediction in the health risk assessment and management in the elderly.