Larger body mass index and waist circumference are associated with lower mortality in Chinese long-term care facility residents

Abstract

Objectives: To investigate the association between body mass index (BMI) and waist circumference (WC) and all-cause mortality of Chinese residents in long-term care facilities in Taiwan.

Design: Prospective cohort study.

Setting: Eight long-term care facilities in Taiwan.

Participants: Three hundred fifty-four residents aged 60 and older (median 78.4, range 60-101; 156 men, 198 women) were recruited during the study period.

Measurements: Anthropometrics and metabolic parameters were measured at baseline. Mean BMI was 21.7 ± 4.2 kg/m(2) (range 11.6-35.3 kg/m(2) , and mean WC was 82.4 ± 10.9 cm (range 55.0-124.0 cm). Mortality data were from the Department of Health in Taiwan.

Results: There were 219 deaths during the 5 years of follow-up. After adjusting for age, sex, albumin, Karnofsky performance status scale, hypertension, and diabetes mellitus, subjects in the highest quartile of BMI (27.3 ± 2.8 kg/m(2) ) and WC (96.7 ± 7.4 cm) had a significantly lower mortality rate than did subjects in the lowest quartile (BMI, 16.7 ± 1.7 kg/m(2) ; WC, 69.6 ± 4.2 cm). After further stratification according to central obesity status, the subjects in the two highest BMI quartiles had a lower mortality rate than those in the lowest BMI quartile but only in the central obesity group (≥ 90 cm in men or ≥ 80 cm in women). The adjusted relative risk for all-cause mortality in the highest versus lowest BMI quartile was 0.17 (95% confidence interval = 0.05-0.57).

Conclusion: BMI and WC were negative predictors for all-cause mortality in older Chinese adults living in long-term care facilities. Participants with higher WC and BMI had lower all-cause mortality.