Relationship between BMI and physical performance among older adults.

Our objective was to examine the relationship between body mass index (BMI) and physical performance in community-dwelling older adults. This was a descriptive and association study, based on secondary data derived from a population-based epidemiological research involving 316 older adults. The BMI was thus classified: <22.0 kg/m(2), underweight; 22.0 ≤ BMI ≤ 27.0 kg/m(2), adequate; >27.0 kg/m(2), overweight. Physical performance was assessed based on "chair stand", "pick up a pen" and walking tests. Associations between BMI and performance at each test were tested by Cox regression for survival analysis with multiple modeling adjusted by gender and age, adopting a significance level of 5% (α = 0.05). Individuals with underweight (βadjusted = 0.64; p = 0.004), performed poorly in the "chair stand" test when compared to individuals with adequate weight. The BMI was a predictor of good physical function, with underweight being more of a limiting factor than overweight.