The bone-adipose axis in obesity and weight loss.

Body fat and lean mass are correlated with bone mineral density, with obesity apparently exerting protection against osteoporosis. The pathophysiological relevance of adipose tissue in bone integrity resides in the participation of adipokines in bone remodeling through effects on deposition and resorption. On the other hand, the skeleton has recently emerged as an endocrine organ with effects on body weight control and glucose homeostasis through the actions of bone-derived factors such as osteocalcin and osteopontin. The cross-talk between adipose tissue and the skeleton constitutes a homeostatic feedback system with adipokines and molecules secreted by osteoblasts and osteoclasts representing the links of an active bone-adipose axis. Given the impact of bariatric surgery on absorption and the adipokine secretory pattern, to focus on the changes taking place following surgical-induced weight loss on this dynamic system merits detailed consideration.