Fragility fracture and its main risk factor, low bone mineral density (BMD), are influenced by common and modifiable lifestyle factors. This study was aimed at evaluating the contribution of lifestyle factors to fracture by using a lifestyle profile approach.

The study involved 1683 women and 1010 men aged 50 years and above who had been followed up for up to 20 years, and during the period, the incidence of new fractures was ascertained by X-ray. Bone mineral density (BMD) at the femoral neck was measured prior to the fracture event. We constructed a lifestyle profile for each individual by summing the 'effects' of dietary calcium intake, physical activity, cigarette smoking, and alcohol intake, weighted by the logarithm of the odds ratio for fracture of each factor. Thus, each individual had a unique 'lifestyle risk score' (LRS), with higher scores being associated with a less healthy lifestyle.

Overall, individuals with a fracture had a significantly higher age-adjusted LRS than those without a fracture, and this difference was observed in either men and women. In the multiple linear regression model, higher LRS was associated with lower femoral neck BMD by 0.048 g/cm² in men and 0.066 g/cm² in women. The proportion of variance in BMD attributed to LRS ranged between 2 and 5%. More importantly, after adjusting for age and BMD, each unit increase in LRS was associated with an increased odds of fracture by 1.97-fold (95% CI, 1.25-3.10) in men. The proportion of fractures attributable to LRS in men was 17%. However, the increased risk of fracture associated with LRS in women was not statistically significant (OR 1.00; 95% CI, 0.54-1.83). Thus, apart from advancing age and lower BMD, less healthy lifestyle factors contribute substantially to increased fracture risk in men.