Growth hormone (GH) and atherosclerosis: changes in morphology and function of major arteries during GH treatment

Patients with hypopituitarism have increased carotid artery intima-media th ickness and reduced arterial distensibility. The effect of 2 years of growt h hormone (GH) replacement therapy on these parameters was studied in 11 GH -deficient men (age range, 24-49 years) with hypopituitarism and compared w ith 12 healthy, age-matched men with no evidence of pituitary or vascular d isease. Before treatment the intima-media of the common carotid arteries an d the carotid bifurcations were significantly thicker in patients (P < 0.00 1) than in the control group. Treatment with GH normalized the intima-media thickness of the common carotid artery within 6 months and of the carotid bifurcation within 3 months. The changes in intima-media thickness of the c arotid artery were negatively correlated with changes in serum levels of in sulin-like growth factor I during treatment. There was a significant improv ement in flow-mediated, endothelium-dependent dilation of the brachial arte ry at 3 months, which was sustained at 6, 18 and 24 months of GH treatment (P < 0.05). Thus, GH replacement therapy in GH-deficient men reverses early morphological and functional atherosclerotic changes in major arteries, an d may reduce rates of vascular morbidity and mortality.