Body mass index and mortality among older people living in the community

OBJECTIVES: To determine if body mass index (BMI weight/height(2)), predictive of mortality in seriously ill hospitalized and institutionalized patients, is also predictive of mortality in a longitudinal epidemiologic study. DESIGN: A prospective cohort study. SETTING: Rovereto, a town in northern Italy. PARTICIPANTS: A consecutive sample of 214 patients aged 81.2 +/- 7.3 years receiving community care services. MAIN OUTCOME MEASURES: Malnutrition and mortality. RESULTS: According to logistic regression analysis, malnutrition status, expressed by a BMI < 22 Kg/m(2), was correlated with dependency in Activity of Daily Living (odds ratio 1.21; 95% confidence interval (CI) 1.01-1.45). Only a low BMI was associated with 1-year survival in Cox regression analysis, after adjusting for potential confounders (relative risk 0.85; 95% CI, 0.74-0.97). A high BMI (>27 Kg/m(2)) was not significantly related to risk of mortality. CONCLUSIONS: Nutrition variables are a cardinal component of comprehensive geriatric assessment. Our results suggest that BMI, a simple anthropometric measure of nutritional status, is an important predictor of mortality among older people living in the community. Even when controlling for clinical and functional variables, a low BMI remained a significant and independent predictor of shortened survival.