Rationale: GH replacement in GH-deficient adults results in an improvement in metabolic status. GH might also decrease visceral adiposity in obese adults that are not GH deficient.
Objective: Our objective was to determine the effects of supraphysiological GH therapy on the metabolic syndrome and visceral adiposity in men with low blood levels of IGF-I and the durability of these effects after stopping GH therapy.
Design: The study was a double-blind, placebo-controlled 6-month intervention trial followed by a blinded follow-up period of 6 months.
Subjects: Thirty nondiabetic middle-aged men with central adiposity (body mass index > 27 kg/m(2); waist circumference > 102 cm) participated.
Results: After 6 months of GH therapy, we observed an increase in weight and lean body mass (2.5 +/- 0.6 kg, P < 0.05 compared with baseline and placebo) and 8.8% reduction in visceral adiposity. GH increased resting energy expenditure by 172.5 +/- 41.6 kcal/24 h after 6 months of therapy. Fasting insulin, glucose, and the quantitative insulin sensitivity check index for insulin resistance increased during GH therapy. The effects of GH on fatness and visceral adiposity disappeared shortly after GH withdrawal, but weight remained increased over baseline and when compared with the placebo group (P < 0.05).
Conclusion: These data suggest that GH therapy is associated with small but statistically significant decreases in visceral adiposity and an increase in lean mass and body weight. In viscerally obese subjects, supraphysiological GH administration is not an effective treatment; however, additional studies are needed to evaluate the effects of low-dose, physiological GH treatment.