Mekala KC and Tritos NA (2008) Effects of recombinant human growth hormone therapy in obesity in adults—a meta-analysis. J Clin Endocrinol Metab [doi:10.1210/jc.2008-1357]

Growth-hormone (GH) secretion is reduced in obesity, but studies of GH therapy in obese individuals have produced conflicting results. A meta-analysis of studies on the effects of recombinant human GH (rhGH) in obese patients suggests that rhGH treatment converts adipose tissue to lean body mass, but without inducing overall weight loss.

Mekala and Tritos examined 24 placebo-controlled studies, which included 539 individuals; median treatment duration was 11.5 weeks. Compared with placebo, treatment with rhGH was associated with significantly decreased mean waist:hip ratio (−0.01), fat mass (−0.9 kg), percent body fat (−1%), visceral adipose area (−22.8 cm2), and total and LDL cholesterol levels (−7 mg/dl and −9 mg/dl, respectively), and increased lean body mass (+1.8 kg). Overall body weight was not affected by rhGH treatment, although BMI decreased in participants who were below the median age (38 years). Treatment was associated with arthralgias, peripheral edema and paresthesias, and also with increased fasting levels of glucose and hyperinsulinemia, although these latter effects disappeared in the studies of long duration.

The authors note that the risks of supraphysiologic concentrations of GH are uncertain—the median dose in the studies analyzed was 31.1 U per week, and the observed benefits were quite small. Further studies of the effects of rhGH on glucose homeostasis and cardiovascular risk in obese individuals are required. The authors suggest that stimulation of endogenous GH with GH-releasing-hormone therapy might avoid some of the possible risks of rhGH treatment.