Diagnosis, Treatment and Safety of Growth Hormone Therapy in Adults

Adult growth hormone (GH) deficiency is a syndrome characterized by abnormal body composition of decreased muscle mass and exercise capacity, increased visceral fat, impaired quality of life, unfavorable alterations in glucose and lipid profiles and markers of cardiovascular risk, decrease in bone mineral density, and increased mortality. Unlike in children where height velocity is a clinical marker, given the lack of specific clinical markers in adults, biochemical confirmation of the diagnosis using appropriate GH stimulation test/s is essential. When dosed appropriately using serum insulin-like growth factor-I (IGF-I) as a serum biomarker, GH replacement therapy is usually well tolerated, with a low incidence of side effects, and improves many of the alterations observed in adult GH deficiency, although beneficial effects on mortality and cardiovascular events, however, remain to be conclusively demonstrated. The potential of GH to act as a mitogen has raised some concerns over the possibility of increased de novo tumors or hypothalamic/pituitary tumor recurrence in adult treated with long-term GH. Though studies of adults who received GH replacement therapy in childhood have produced conflicting reports in this area, there have been several long-term surveillance studies of adults on GH replacement therapy that have provided reassuring data by demonstrating no increase in cancer risk or mortality.