Effects of growth hormone on heart structure and function in adolescence

Until recently, growth hormone (GH) and insulin-like growth factor 1 (IGF-1) were considered to control only linear growth. Apart from growth effect, GH has additional important physiological functions in the human body influencing several metabolic processes, body composition, muscle strength, and bone mineral density. In adolescence, where the majority of these physiological functions reach a zenith, GH plays a crucial role. The ability of GH to trigger cardiac muscle growth by direct and indirect effects plays a pivotal role in the physiology of the heart. Patients with childhood or adulthood onset of GH deficiency are exposed to increased risk for cardiovascular morbidity. GH treatment may have beneficial effect on the cardiovascular system in GH deficient adolescents. On the other hand discontinuation of GH treatment in these patients may result in the accumulation of relevant cardiovascular risk factors such as increase in body and abdominal fat and LDL and total cholesterol concentrations. No potential adverse cardiac effects of GH therapy have been so far demonstrated in short stature patients with normal GH secretion. Nevertheless, no evidence of heart hypertrophy or cardiomypathy has been documented in adolescents with GH excess has been reported in adults. Nonetheless, normalization of GH and IGF-1 levels in such patients is essential in order to arrest cardiovascular disease later in life.