Effect on Muscles of Long-Term Treatment with Growth Hormone (GH) in Adults with GH Deficiency: KIMS Data and Review of the Literature

Abstract

Growth hormone (GH) deficiency in adulthood, irrespective of aetiology, is associated with decreases in lean body mass (LBM) and muscle strength. Early studies indicated that GH replacement in adults with GH deficiency (GHD) normalized LBM and muscle strength, but these findings were complicated because the GH dose used in these early studies was calculated based on weight (as in children) and was subsequently found to be too high for adults, resulting in insulin-like growth factor I levels as high as those seen in individuals with acromegaly. More recent studies have, however, confirmed that GH replacement has a long-term beneficial effect on muscle mass and function in patients with GHD of all ages, although there appears to be a greater effect in normalizing muscle mass and function in young males and in adults with adult-onset GHD compared with those with childhood-onset GHD. Results also suggest that concomitant exercise training might further improve the outcome of GH replacement therapy.