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

Introduction: 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.

Methods: This longitudinal prospective population-based cohort study evaluated 433 community-dwelling women aged 65 years 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 4.3 years. 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.

Results: The mean age was 72.8 ± 4.7 years, and 28 incident non-spine osteoporotic fractures were identified after a mean follow-up time of 4.3 ± 0.8 years. According to the Lipschitz classification for nutritional status in the elderly, 38.6 % of women were nonobese (BMI ≤ 27 kg/m) 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]).

Conclusion: This study suggests a potential negative effect of visceral adiposity on bone health in nonobese women.