Visceral fat measured by DXA is associated with increased risk of non-spine fractures in nonobese elderly women: a population-based prospective cohort analysis from the São Paulo Ageing & Health (SPAH) Study.

Abstract

The protective effect of obesity on bone health has been questioned because visceral fat has been demonstrated to have a deleterious effect on bone. The aim of this study was to investigate the association of visceral fat measured by DXA with the incidence of non-spine fractures in community-dwelling elderly women. This longitudinal prospective population-based cohort study evaluated 433 community-dwelling women aged 65years or older. A specific clinical questionnaire, including personal history of a fragility fracture in non-spine osteoporotic sites, was administered at baseline and after an average of 4.3years. All incidences of fragility fractures during the study period were confirmed by affected-site radiography. Visceral adipose tissue (VAT) was measured in the android region of a whole-body DXA scan. The mean age was 72.8 ± 4.7years, and 28 incident non-spine osteoporotic fractures were identified after a mean follow-up time of 4.3 ± 0.8years. According to the Lipschitz classification for nutritional status in the elderly, 38.6% of women were nonobese (BMI ≤ 27kg/m2) and 61.4% were obese/overweight. Logistic regression models were used to estimate the relationship between VAT and non-spine fractures in elderly women. After adjusting for age, race, previous fractures, and BMD, VAT (mass, area, volume) had a significant association with the incidence of non-spine fractures only in nonobese elderly women (VAT mass: OR, 1.42 [95% CI, 1.09-1.85; p = 0.010]; VAT area: OR, 1.19 [95% CI, 1.05-1.36; p = 0.008]; VAT volume: OR, 1.40 [95% CI, 1.09-1.80; p = 0.009]). This study suggests a potential negative effect of visceral adiposity on bone health in nonobese women.