Cardiovascular effects of growth hormone therapy in adults with childhood-onset growth hormone deficiency

Cardiac structure and function were evaluated by two-dimensional, M-mode and Doppler echocardiograms in eight adults with childhood-onset growth hormone deficiency (GHD) before and after 6 months .of growth hormone (GH) therapy, 0.5 ID/kg/week. An exercise test was also performed using a modified Bruce protocol, with a bicycle ergometer. Before therapy, values (mean ±SEM) for intraventricular septa) thickness (7.1 ±0.3 mm), left ventricular (LV) posterior wall thickness (LVPT; 5.2 ±0.1 mm), LV mass (LVM; 46.6 ±5.6 g), LVM index (LVM/body surface area; LVMI; 33.9 ±2.6 g/m2), LV end-diastolic diameter (41.5 ±0.6 mm) and LV ejection time (LVET; 251.2 ±10.6 milliseconds) in patients with GHD were lower (P<0.001) than those in controls, while LV pre-ejection period (PEP)/LVET (0.36 ±0.02) values were higher (P <0.01). LV end-systolic diameter, PEP, ejection fraction and parameters of LV diastolic function (peak protodiastolic velocity (E), peak telediastolic velocity (A) and E/A) in patients were similar to those in the controls. GH therapy increased (P <0.0001) LVPT (6.8 ±0.2 mm), LVM (57.4 ±5.3 g) and LVMI (41.7 ±2.2 g/m2) and reduced PEP (76.7 ±1.7 milliseconds; P<0.0001), LVET (236 ±8.0 milliseconds; P <0.05) and PEP/LVET (0.32 ±0.01; P<0.01) values; no significant changes were observed for the other parameters. The exercise test showed a significant improvement in cardiac performance, as demonstrated by a reduction in the product of blood pressure x heart rate at the same workload (basal, 33067 ±842; after GH, 25638 ±444; P<0.0001). These findings support a role for GH in the maintenance of normal cardiac performance in adults and suggest that GH treatment might ameliorate the cardiac structure and function of patients with GHD. To date, the long-term effects of this therapy on the future prognosis of adults with GHD remain to be clarified.