Differential effects of short-term growth hormone therapy on the cardiovascular risk profile in patients with chronic kidney disease: a pilot study.

Chronic kidney disease (CKD) is highly associated with an increased cardiovascular morbidity and mortality and is also a state of growth hormone (GH) resistance. We examined the impact of a short-term treatment with rhGH on circulating markers of cardiovascular risk in nonmalnourished CKD patients in a single-center, nonrandomized pilot study. Patients with stable CKD Stage 3 - 5 and age- and sex-matched healthy controls (n = 15 each) received a 7-day treatment with rhGH (1.33 mg/m2 body surface area per day, approximately 30 microg/kg). Prior to onset of rhGH therapy, at the end of the treatment period and at the end of a 7-day wash-out period blood was drawn to assess changes in circulating markers of cardiovascular risk. At time of enrollment CKD patients showed elevated serum concentrations of phosphate, calcium x phosphate product, PTH, fibroblast growth factor-23 (FGF-23), triglycerides, leptin and homocysteine compared to controls. In patients and controls rhGH treatment induced an increase in circulating insulin-like growth factor I (IGF-I), and the molar ratio of IGF-I/IGF binding protein 3 as well as an elevation of glucose, insulin, and triglycerides, whereas serum urea was decreased. In CKD patients, rhGH treatment raised concentrations of leptin, whereas LDL-cholesterol, homocysteine, phosphate, and 25-hydroxyvitamin D were significantly reduced. In controls, but not in CKD patients, rhGH raised 1,25-dihydroxy-vitamin D3 serum levels, which were even more elevated at the end of the wash-out period. In conclusion, short-term treatment with rhGH in CKD patients affects not only insulin and glucose metabolism but also affects serum lipid profile, i.e., LDL-cholesterol, leptin and homocysteine. Long-term trials are required to evaluate the impact of rhGH on cardiovascular morbidity and mortality.