Soft tissues and bone health in sedentary women: A cross-sectional study

Lean mass is a strong determinant of bone mass, however, there is controversial surrounding the role of fat mass. The aim of this study was to examine the association between lean mass and fat mass with bone mass in middle-aged sedentary women, including relevant covariates. A cross-sectional study was performed on a total of 55 healthy and sedentary women. Dual energy x-ray absorptiometry was used to measure bone mineral content and areal bone mineral density at the whole body, lumbar spine and hip. The relationships between lean and fat mass with bone outcomes were analysed using three regression models: model 0 using unadjusted data, model 1 was adjusted by age and stature and model 2 added lean mass or fat mass (depending on the predictor). Lean mass was positively associated with most bone mineral content and areal bone mineral density outcomes in models 0 and 1, and the majority of these associations remained significant in model 2 (after adjusted by fat mass). Fat mass was positively associated with some of the bone mineral content and areal bone mineral density outcomes in models 0 and 1, and interestingly all associations disappeared in model 2 (after adjusted by lean mass). The main finding of this study was that lean mass was positively related to bone outcomes, independent of age, stature and fat mass in middle-aged sedentary women. In addition, the association between fat mass and bone outcomes seems to be explained by lean mass.