Survival benefit of abdominal adiposity: a 6-year follow-up study with Dual X-ray absorptiometry in 3,978 older adults.

In contrast to that in the middle-aged, higher body mass index (BMI) in older people is associated with higher survival rates. Yet, BMI makes no distinction between fat elsewhere and abdominal fat, the latter being metabolically more harmful. We hypothesized that overall adiposity might be protective in old age, but that central fat might offset that benefit and remained harmful as in the middle-aged. Three thousand nine hundred seventy-eight Chinese elderly ≥65 years had demographics, medical conditions, physical activity, and body composition by DXA recorded at baseline. Overall adiposity was measured as whole body fat%, and abdominal adiposity as waist circumference, waist-hip ratio, and relative abdominal fat (RAF) (relative abdominal fat = abdominal fat according to anatomical landmarks/whole body fat). Deaths within 1 year from baseline were excluded from analysis. All-cause and cardiovascular mortality were analyzed using Cox regression, adjusted for covariates. The lowest quintile of adiposity measurements was used for comparison. After a mean follow-up of 72.3 months, 13.7% men and 4.5% women had died. In men, the highest two quintiles of whole body fat % and the upper four quintiles of RAF were associated with significantly lower all-cause mortality, and adjusted hazard ratio (95% CI) in ascending quintiles of RAF compared with the lowest quintile was 0.62 (0.43-0.89), 0.58 (0.4-0.85), 0.52 (0.36-0.77), and 0.67 (0.47-0.96). No relationship was found between abdominal adiposity and cardiovascular mortality in both genders. Higher whole body fat % as well as higher proportion of abdominal fat was associated with lower all-cause mortality in men. No such relation was found in women.