>Illicit use of human growth hormone and insulin-like growth factor I is common among male weightlifters, and use in this population is often associated with polysubstance abuse involving both performance-enhancing and classical drugs, researchers found.
To augment conflicting data on GH abuse, researchers compared three groups of men: those reporting lifetime use of GH or IGF-I; those reporting anabolic-androgenic steroid use but no GH or IGF-I; and those reporting no use.
Of the 231 men polled for the study, 43% reported lifetime steroid use, with 26 men reporting lifetime GH use and one reporting IGF-I use but no GH use. These 27 men had tried GH or IGF-I after steroids, the researchers said. Eighty-one percent also reported current or past dependence on steroids.
Long-term steroid use was more common among those who used GH or IGF-I. The median total lifetime duration was 173 weeks compared with 24 weeks among steroid users who had not tried either substance.
At 56%, the proportion of GH or IGF-I users who described past dependence on at least one drug other than alcohol or cannabis was highest of those in all three groups, according to the researchers. Many reported abusing opiates, methylenedioxymethamphetamine, cocaine and stimulants.
“Although [GH] does not produce a ‘reward’ of acute intoxication in the manner of classical dependence-inducing drugs such as alcohol or opioids, the possibility remains that its metabolic effects, or perhaps even subtle hedonic effects, might themselves be sufficiently reinforcing to induce a dependence syndrome in some individuals,” the researchers wrote.
According to other results, men using GH or IGF-I were considerably more muscular and had longer histories of weightlifting compared with nonusers. In addition, only 19% had college degrees and most were generally less educated, although they were usually older than men in the other two groups.
Declining prices and greater availability of GH, IGF-I and other performance-enhancing drugs in future years may result in an even greater number of users than suggested in this study, who use these drugs in higher doses and for longer periods.
“The long-term risks of high-dose [GH] use are little studied, but available evidence suggests that long-term high-dose [GH] may have serious medical consequences, including cardiac, endocrine and respiratory effects, as well as increased risk for certain cancers,” Brian P. Brennan, MD, MSc, of McLean Hospital in Belmont, Mass., and Harvard Medical School in Boston, said in a press release. “Our findings suggest that mounting illicit [GH] abuse may represent a dangerous new form of drug abuse with potentially severe public health consequences.”