Weight, shape, and mortality risk in older persons: elevated waist-hip ratio, not high body mass index, is associated with a greater risk of death.

Abstract

Background: Guidelines for optimal weight in older persons are limited by uncertainty about the ideal body mass index (BMI) or the usefulness of alternative anthropometric measures.

Objective: We investigated the association of BMI (in kg/m(2)), waist circumference, and waist-hip ratio (WHR) with mortality and cause-specific mortality.

Design: Subjects aged >/=75 y (n = 14 833) from 53 family practices in the United Kingdom underwent a health assessment that included measurement of BMI and waist and hip circumferences; they also were followed up for mortality.

Results: During a median follow-up of 5.9 y, 6649 subjects died (46% of circulatory causes). In nonsmoking men and women (90% of the cohort), compared with the lowest quintile of BMI (<23 in men and <22.3 in women), adjusted hazard ratios (HRs) for mortality were <1 for all other quintiles of BMI (P for trend = 0.0003 and 0.0001 in men and women, respectively). Increasing WHR was associated with increasing HRs in men and women (P for trend = 0.008 and 0.0002, respectively). BMI was not associated with circulatory mortality in men (P for trend = 0.667) and was negatively associated in women (P for trend = 0.004). WHR was positively related to circulatory mortality in both men and women (P for trend = 0.001 and 0.005, respectively). Waist circumference was not associated with all-cause or circulatory mortality.

Conclusions: Current guidelines for BMI-based risk categories overestimate risks due to excess weight in persons aged >/=75 y. Increased mortality risk is more clearly indicated for relative abdominal obesity as measured by high WHR.