Association between abdominal obesity and fracture risk: a prospective study

Higher body weight is associated with greater bone mineral density (BMD) and lower fracture risk. However, the relationship between abdominal fat mass (aFM) and fracture risk is unclear because of limited prospective data. The present study sought to examine the association between aFM, BMD, and fracture risk.

The study was designed as a prospective investigation, in which a sample of 1126 participants (360 men and 766 women) aged 50 years or older had been continuously followed up for an average of 5 years. The mean age of participants was 71 years (range, 57-94 years). At baseline, BMD at the femoral neck and lumbar spine and aFM were measured by dual-energy X-ray absorptiometry. The incidence of low-trauma and nonpathological fractures was ascertained prospectively from X-ray reports.

During the follow-up period, 19 men and 107 women had sustained a fracture. In women, each 1-kg lower aFM was associated with a 50% higher risk of fracture (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.10-2.05) after adjustment for age, femoral neck BMD, falls, stature, physical activity, and prior fracture. Subgroup analysis by fracture type found that the association was mainly observed in clinical vertebral fracture (HR, 1.96; 95% CI, 1.22-3.13). In men, although there was no statistically significant association between aFM and fracture risk (HR, 1.15; 95% CI, 0.58-2.25), the strength of this finding is affected negatively by the low number of fractures.

Lower abdominal fat was significantly associated with an higher fracture risk in women.