For example, growth hormone receptor knockout (GHRKO) mice have decreased femoral length, as well as decreased BMD, resulting from reduced cortical bone area.(5) Conversely, in human acromegaly, excessive GH secretion has been linked to increased BMD(6) and is associated with a decrease risk of fracture.(7) The proper regulation of GH action has implications not only for growth but also for aging and fracture risk. Here, GHR is linked to acromegaly.