Association Between Body Mass Index and Mortality in an 80‐Year‐Old Population

OBJECTIVES: To evaluate the association between body mass index (BMI) and all‐cause mortality and cardiovascular disease (CVD) in an 80‐year‐old population. DESIGN: Cohort study. SETTING: Community‐based. PARTICIPANTS: Six hundred ninety‐seven of 1,282 (54.4%) 80‐year‐old candidate individuals. MEASUREMENTS: The dates and causes of all deaths were followed up for 4 years. RESULTS: The relative hazard ratios (HRs) for all‐cause mortality were lower in overweight subjects (BMI≥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. CONCLUSION: Overweight status was associated with longevity and underweight with short life, due to lower and higher mortality, respectively, from CVD and cancer.