Obesity is an important risk factor for osteoporosis and fractures. With the growing
prevalence of obesity in the U.S., understanding the pathophysiology of bone loss in this
population is of importance to public health. Growth hormone (GH) is a critical mediator of
bone homeostasis and is markedly reduced in obesity. Our preliminary data suggest an
important role for the GH/insulin-like growth factor 1 (IGF-1) system in the pathogenesis of
bone loss in obesity. The development of novel imaging techniques provides an opportunity to
investigate the effects of GH on skeletal structure and strength, which will provide insights
into the pathogenesis of obesity related bone loss. Understanding the pathophysiology of bone
loss in obesity may help identify new treatment targets for this important complication. The
investigator hypothesizes that low-dose GH administration for 18 months will improve skeletal
health.