chapter  22
44 Pages

Obesity, Adipose Tissue, and Bone

It is well established that a higher body weight or obesity has a positive correlation with bone, and a low body weight or loss of weight is associated with bone loss and fracture risk. The greater bone mass in obesity may result from the greater mechanical load on bone due to excess weight, an altered dietary intake, or hormones/adipokines produced by the excess adipose tissue. Furthermore, the regional distribution of fat may also in—uence bone mass independently of obesity (Tarquini et  al., 1997; Warming et  al., 2003; Kuwahata et  al., 2008). Whereas obesity may affect speci„c bones differently, speci„c bone sites may also be affected differently due to weight bearing or the cortical:trabecular content of a particular bone. This weight-bone relationship is not gender speci„c, and it is also found in children, although severe obesity at greater levels of adiposity observed typically only in Western countries may attenuate the positive effect on bone and/or bone quality in children. Obesity is associated with higher areal bone mineral density (aBMD), yet the impact of excess adiposity on bone quality, especially modi„cation of the trabecular and cortical compartments, presents a more complicated picture that may actually lead to an increase in fracture risk.