Association between body mass index and falls in community-dwelling men and women: a prospective, multinational study in the Survey of Health, Ageing and Retirement in Europe (SHARE)

Purpose: To investigate the longitudinal associations between body mass index (BMI) categories and falls risk in men and women.

Methods: Prospective cohort study using data from 50,041 community-dwelling adults aged ≥ 50 years assessed in Wave 6 and 7 in the cross-national Survey of Health, Ageing and Retirement in Europe (SHARE). Socio-demographic and clinical factors were assessed at baseline (Wave 6). Functional impairment was defined by any limitations in activities of daily living (ADL) or instrumental ADL (IADL). Participants were classified as underweight, normal weight, overweight or obese at baseline. At 2-year follow-up (Wave 7), falls in the previous six months were recorded. The longitudinal associations between BMI categories and falls were analysed by binary logistic regression models; odds ratios (OR) and 95% confidence intervals (CI) were calculated. All analyses were adjusted for socio-demographic and clinical factors. Furthermore, analyses were stratified by sex, age and functional impairment.

Results: Mean age was 67.0 years (range 50-102); 28,132 participants were women; 4057 (8.1%) participants reported falls at follow-up. Participants had an increased falls risk [OR (95% CI)] if they were underweight [1.41 (1.06-1.88), p = 0.017] or obese [1.20 (1.09-1.32), p < 0.001] compared to those with normal weight. The association of underweight and obesity with increased falls risk was consistent in participants aged ≥ 65 years. In participants with functional impairment, underweight was associated with higher falls risk [1.61 (1.09-2.40), p = 0.018], while obesity was not.

Conclusion: A U-shaped relationship between BMI and falls risk was found in community-dwelling adults.