Preventive Effect of Long-Term GH Therapy on Cardiovascular Risk Factors in Patients with GH Deficiency

Abstract

GH has some influence on cardiovascular risk factors. The effects of long-term GH replacement therapy on hemostatic and lipid parameters were examined in pediatric patients with GH deficiency. Hemostatic markers (fibrinogen, D-dimer, TAT, tPA-PAI, and PIC) and lipid parameters (total cholesterol, HDL-cholesterol, LDL-cholesterol, and Lp (a)) were evaluated in 30 pediatric patients before and during GH therapy. They were treated with recombinant GH (0.5 I.U. /kg/week) for 2.4±0.5 years. Eight patients had complete GH deficiency (aged 10.6±3.3 years; 5 males and 3 females), including 4 with craniopharyngioma (13.7±5.4 years; 2 males and 2 females), and 22 had partial GH deficiency (10.6±3.3 years; 11 males and 11 females). Statistical analysis was done with the Mann-Whitney nonparametric rank sum test. Plasma D-dimer (p<0.01) and fibrinogen (p<0.01) decreased after 2.4±0.5 years of GH treatment. There were no significant changes in total cholesterol, triglycerides, or HDL-and LDL-cholesterol, but there was an increase in lipoprotein (a) (p<0.02) and insulin (p<0.02). The free T₃ (p<0.0003) and TSH (p<0.003) levels decreased, but there was no effect on free T₄or the body mass index. Decreased hemostatic activity is a beneficial effect of GH on cardiovascular risk factors. Ceasing GH therapy by 20 years of age on completion of growth might lead to the onset of cardiovascular disease in adult life, so continuing GH therapy beyond this age may be necessary.