Body mass index and long-term mortality in an elderly Mediterranean population.

OBJECTIVES: To describe the relationship of body mass index and mortality in older adults, examining the influence of sex and cardiovascular morbidity. METHODS: Sixteen-year cohort of a population sample of 1,008 people aged 65 and over. BMI mortality hazard ratios are estimated controlling for age, sex, education, physical activity, smoking, chronic conditions, and ADL (activities of daily living) disability. RESULTS: At baseline the median BMI is 26.8 (Interquartile range: 24.2-29.7 Kg/m(2)). Findings show that during 16 years there were 672 deaths. The U-shaped curve of the mortality hazard by BMI is wide. The minimum mortality occur at BMI = 30.5 Kg/m(2). Findings show that men had lower mortality risk with increasing BMI and that cardiovascular disease was associated with high mortality in the low-BMI category. DISCUSSION: Underweight is a risk factor for mortality among elderly people, whereas overweight and mild obesity are associated with the lowest mortality particularly among men and those with cardiovascular morbidity.