Growth hormone as an anti-aging therapy-do the benefits outweigh the risks?
- Barkan, Ariel L
SYNOPSIS
BACKGROUND
Growth hormone (GH) is frequently used off-label to treat the signs and symptoms of aging; however, the benefits and risks of this therapy have not been adequately assessed.
OBJECTIVE
To evaluate the efficacy and safety of GH as an anti-aging therapy.
DESIGN AND INTERVENTION
This was a systematic review of previously published studies of GH therapy in healthy, elderly individuals. A literature search of MEDLINE and EMBASE was performed to identify randomized, controlled trials that compared GH therapy with no GH therapy or that compared GH plus lifestyle intervention (diet and/or exercise) with lifestyle intervention alone. Eligible studies enrolled ≥10 participants who received the study intervention for ≥2 weeks. Studies that assessed GH as a treatment for a specific illness (e.g. GH deficiency) or those that enrolled patients with diabetes, thyroid disease, cardiac disease, osteoporosis, or renal failure were excluded.
OUTCOME MEASURES
The main outcome measures were study quality (e.g. design and statistical analyses), study cohort characteristics (e.g. age and sex), study interventions (e.g. dose and duration of therapy), and clinical outcomes, which included body composition, bone dynamics, insulin resistance, cardiovascular risk factors, quality of life, and adverse events.
RESULTS
A total of 31 articles-which described the results of 18 studies-were included in the analysis. GH therapy was compared with no GH therapy in 12 of the 18 studies. The mean age was 69 years, and participants were predominantly male (67%) and overweight (mean BMI 28 kg/m2). Individual study populations were small (mean number of participants 28) and had high drop-out rates. The mean duration of treatment was 26.6 weeks and 220 participants who received GH therapy completed their respective studies (equivalent to 107 person-years). Serum insulin-like growth factor 1 (IGF-I) levels increased by 88% in the GH-treated patients, compared with only 2% in patients not receiving GH. Treatment with GH was associated with decreased fat mass (2.08 kg, P<0.001) and increased lean body mass (2.13 kg, P<0.001); however, the amount of weight loss associated with GH treatment was not statistically significant (0.1 kg). Women had less improvement in body composition than men treated with GH; however, the net effects of GH on body composition were unaffected by treatment duration. Although GH therapy resulted in a modest decrease in total cholesterol levels (0.29 mmol/l), all other outcomes were unaffected. GH therapy was associated with a high incidence of soft tissue edema (50%), arthralgia (21%), carpal tunnel syndrome (19%) and gynecomastia (5%). Edema was more common in women than men in the GH-treated population (61% versus 47%). Patients receiving GH also had an increased likelihood of impaired glucose regulation (22%) or new-onset diabetes (5%).
CONCLUSION
GH offers few benefits and is associated with a high rate of adverse events when used as an anti-aging therapy in healthy, elderly individuals.