Influence of long-term growth hormone replacement on leptin and ghrelin in GH deficiency before and after glucose load

Abstract

Introduction This cross-sectional study was performed to evaluate the effect of long-term GH substitution on leptin and ghrelin in GH deficiency (GHD). Methods Leptin and ghrelin were measured after glucose load for 3 h in 52 pat and 10 age- and BMI-matched healthy controls. 22 GHD pat were on GH substitution (GH-Sub) for a median of 10 yr (range 2–27 yr). 30 age- and BMI-matched GHD pat were not substituted for at least 2 yr (non-Sub). Results Basal leptin (8 µg/l (1–130) vs. 16 µg/l (3–89), p < 0.05) and AUC of leptin ( p < 0.05) was significantly lower in GH-Sub compared to non-Sub. In the control group, leptin was higher compared to GH-Sub and similar to non-Sub (19 µg/l (4–57)). Ghrelin (baseline: non-Sub 113 ng/l (61–270), GH-Sub 145 ng/l (83–280), controls 131 ng/l (83–274)) were slightly but not significantly lower for non-Sub. After glucose load, a significant decrease in leptin appeared in both GHD groups, but not in the control group. Ghrelin decreased significantly in all groups. Conclusion Lipolytic GH causes lower leptin in GH-Sub. The reason for similar ghrelin might be the compensating effect of acute GH suppression and stimulating low fat mass on ghrelin. Leptin regulation after glucose load is impaired in GHD, whereas ghrelin regulation seems to be not effected.