Association between body mass index and mortality in an 80-year-old population

To evaluate the association between body mass index (BMI) and all-cause mortality and cardiovascular disease (CVD) in an 80-year-old population.

Cohort study.

Community-based.

Six hundred ninety-seven of 1,282 (54.4%) 80-year-old candidate individuals.

The dates and causes of all deaths were followed up for 4 years.

The relative hazard ratios (HRs) for all-cause mortality were lower in overweight subjects (BMI > or= 25.0) than in underweight (BMI<18.5) or normal-weight (BMI 18.5-24.9) subjects. Similarly, the HRs for mortality due to CVD in overweight subjects were 78% less (HR=0.22, 95% confidence interval (CI)=0.06-0.77) than those in underweight subjects, and those in normal weight subjects were 78% less (HR=0.22, 95% CI=0.08-0.60) than those in underweight subjects. Mortality due to CVD was 4.6 times (HR 4.64, 95% CI=1.68-12.80) as high in underweight subjects as in normal-weight subjects, and mortality due to cancers was 88% lower (HR=0.12, 95% CI=0.02-0.78) in the overweight group than in the underweight group. There were no differences in mortality due to pneumonia.

Overweight status was associated with longevity and underweight with short life, due to lower and higher mortality, respectively, from CVD and cancer.