Factors associated with being underweight among elderly community-dwellers from seven Brazilian cities: The FIBRA study

Abstract

The aim of this study was to assess the prevalence of being underweight among the elderly according to demographic and socioeconomic characteristics, health-related behaviors, diseases and health status. This was a cross-sectional multi-center study with 3,478 community-dwelling elders (≥ 65 years). The dependent variable was the prevalence of being underweight, classified by Body Mass Index < 22kg/m2. Adjusted prevalence rate ratios were estimated using multivariable Poisson regression. The mean age was 72.9 years and 12.0% of the elderly were underweight (CI95%:10.9-13.1). Aged elderly ≥ 80 years, former and current smokers, those who reported appetite loss and those classified as pre-frail or frail (PR=1.41; CI95%:1.09-1.82) presented a higher prevalence of being underweight. Individuals who received medical diagnosis of hypertension, diabetes and rheumatism had the lowest underweight prevalence observed. The results highlight the importance of nutritional status assessment and monitoring among the elderly, with emphasis on the most vulnerable subgroups, particularly the frail elderly, taking into account the health consequences of low weight.