GH deficiency (GHD) negatively influences cardiovascular function directly by impairing cardiac filling, performance, and contractility and indirectly by inducing atherosclerotic changes, hypercoagulability, abdominal obesity, insulin resistance, dislipidemia, endothelial dysfunction, etc. This accounts for the reduced life expectancy and increased risk of death for vascular disease in these patients.
CFR represents the capacity of the coronary circulation to dilate following an increase in myocardial metabolic demands and is considered an endothelial function index.
We investigated the cardiac and endothelial function and evaluated coronary microvascular circulation in a group of adult onset GHD patients during the first year of GH replacement therapy.
We studied 13 (7 males, 6 females aged 56.43±4.49 years) patients (all nonsmokers, non diabetics, without hypertension or vascular disease) with adult-onset hypopituitarism and GHD before and after 1 year of GH therapy. In these patients CFR, echocardiographic analysis (cardiac mass, systolic and diastolic function), IGF-I plasma levels, lipid profile, HbA1c, blood pressure and anthropometric data were recorded before GH therapy and after 12 months of continuous therapy (mean starting dose 1.2±0.19 mg/week adjusted every 810 weeks on the basis of IGF-I response).
After GH administration a significant improvement of cardiac mass (P<0.02) and CFR (from 2.35±0.24 to 2.88±0.25; P<0.02) has been observed; systolic blood pressure decreased significantly (from 135.38±3.51 mmHg to 125.77±4.04 mmHg; P<0.02) as well as LDL Cholesterol (from 143.25±7.16 mg/dl to 124.51±5.99 mg/dl; P<0.05). Improvement in diastolic filling was also observed.
In conclusion these data show that GH therapy improves endothelial and cardiac performance and, therefore, can prevent the progression of the atherosclerotic processes in GHD by reducing these cardiovascular risk factors.