[Associations of waist-to-hip ratio with mortality in older adults in 10 areas of China].

Objective: To evaluate the associations of waist-to-hip ratio (WHR) and BMI-adjusted WHR (WHRadjBMI) with all-cause, cardiovascular disease (CVD)-attributed, and non-CVD-attributed mortality in elderly population in China. Methods: This study used data from the China Kadoorie Biobank, which included 109 796 individuals aged ≥60 years. WHRadjBMI was derived by using linear regression residual method by fitting WHR against age, sex, and BMI and extracting standardized residuals. Cox proportional hazards regression models were used to estimate HRs and 95%CIs for the associations of WHR and WHRadjBMI with mortality, potential non-linear association and effect modifications by key demographic and lifestyle factors were also evaluated. Results: During a median follow-up of 15.17 years, 44 191 deaths were recorded. After multivariate adjustment, WHR showed a U-shaped association with all-cause mortality, whereas WHRadjBMI showed monotonic increased association with all the mortality. When participants were divided by the median of WHRadjBMI, those in high WHRadjBMI group had significantly increased risks for all-cause mortality (HR=1.16, 95%CI: 1.14-1.18), CVD-attributed mortality (HR=1.19, 95%CI: 1.15-1.22), and non-CVD-attributed mortality (HR=1.14, 95%CI: 1.11-1.17), compared with those in low WHRadjBMI group. Subgroup analyses indicated stronger associations in individuals aged <70 years, rural residents, and those with lower income or education levels (P<0.05). Conclusions: WHRadjBMI is independently and positively associated with all-cause and cause-specific mortality risks in elderly population in China, which can be used as a robust indicator of abdominal obesity and a predictor of mortality in the health management of elderly population.