Background: Human growth hormone (GH) is widely used as an antiaging therapy, although its use for this purpose has not been approved by the U.S. Food and Drug Administration and its distribution as an antiaging agent is illegal in the United States.
Purpose: To evaluate the safety and efficacy of GH therapy in the healthy elderly.
Data sources: The authors searched MEDLINE and EMBASE databases for English-language studies published through 21 November 2005 by using such terms as growth hormone and aging.
Study selection: The authors included randomized, controlled trials that compared GH therapy with no GH therapy or GH and lifestyle interventions (exercise with or without diet) with lifestyle interventions alone. Included trials provided GH for 2 weeks or more to community-dwelling participants with a mean age of 50 years or more and a body mass index of 35 kg/m2 or less. The authors excluded studies that evaluated GH as treatment for a specific illness.
Data extraction: Two authors independently reviewed articles and abstracted data.
Data synthesis: 31 articles describing 18 unique study populations met the inclusion criteria. A total of 220 participants who received GH (107 person-years) completed their respective studies. Study participants were elderly (mean age, 69 years [SD, 6]) and overweight (mean body mass index, 28 kg/m2 [SD, 2]). Initial daily GH dose (mean, 14 microg per kg of body weight [SD, 7]) and treatment duration (mean, 27 weeks [SD, 16]) varied. In participants treated with GH compared with those not treated with GH, overall fat mass decreased (change in fat mass, -2.1 kg [95% CI, -2.8 to -1.35] and overall lean body mass increased (change in lean body mass, 2.1 kg [CI, 1.3 to 2.9]) (P < 0.001), and their weight did not change significantly (change in weight, 0.1 kg [CI, -0.7 to 0.8]; P = 0.87). Total cholesterol levels decreased (change in cholesterol, -0.29 mmol/L [-11.21 mg/dL]; P = 0.006), although not significantly after adjustment for body composition changes. Other outcomes, including bone density and other serum lipid levels, did not change. Persons treated with GH were significantly more likely to experience soft tissue edema, arthralgias, carpal tunnel syndrome, and gynecomastia and were somewhat more likely to experience the onset of diabetes mellitus and impaired fasting glucose.
Limitations: Some important outcomes were infrequently or heterogeneously measured and could not be synthesized. Most included studies had small sample sizes.
Conclusions: The literature published on randomized, controlled trials evaluating GH therapy in the healthy elderly is limited but suggests that it is associated with small changes in body composition and increased rates of adverse events. On the basis of this evidence, GH cannot be recommended as an antiaging therapy.