Growth Hormone Decreases Visceral Fat and Improves Cardiovascular Risk Markers in Women with Hypopituitarism: A Randomized, Placebo-Controlled Study

Abstract

Abstract Context: Data regarding gender-specific efficacy of GH on critical endpoints are lacking. There are no randomized, placebo-controlled studies of physiological GH therapy solely in women. Objective: Our objective was to determine the effects of physiological GH replacement on cardiovascular risk markers and body composition in women with GH deficiency (GHD). Design: This was a 6-month, randomized, placebo-controlled, double-blind study. Setting: The study was conducted at the General Clinical Research Center. Study Participants: 43 women with GHD due to hypopituitarism were included in the study. Intervention: Study participants were randomized to receive GH (goal mid-normal serum IGF-1) or placebo. Main Outcome Measures: Cardiovascular risk markers, including high-sensitivity C-reactive protein, tissue plasminogen activator, and body composition, including visceral adipose tissue by cross-sectional computed tomography, were measured. Results: Mean daily GH dose was 0.67 mg. The mean IGF-1 sd score increased from −2.5 ± 0.3 to −1.4 ± 0.9 (GH) (P < 0.0001 vs. placebo). High-sensitivity C-reactive protein decreased by 38.2 ± 9.6% (GH) vs.18.2 ± 6.0% (placebo) (P = 0.03). Tissue plasminogen activator and total cholesterol decreased, and high-density lipoprotein increased. Homeostasis model assessment-insulin resistance and other markers were unchanged. Body fat decreased [−5.1 ± 2.0 (GH) vs. 1.9 ± 1.0% (placebo); P = 0.002] as did visceral adipose tissue [−9.0 ± 5.9 (GH) vs. 4.3 ± 2.7% (placebo); P = 0.03]. Change in IGF-1 level was inversely associated with percent change in visceral adipose tissue (r = −0.61; P = 0.002), total body fat (r = −0.69; P < 0.0001), and high-sensitivity C-reactive protein (r = −0.51; P = 0.003). Conclusions: Low-dose GH replacement in women with GHD decreased total and visceral adipose tissue and improved cardiovascular markers, with a relatively modest increase in IGF-1 levels and without worsening insulin resistance.