Natural Health

Questions on Safety of Human Growth Hormone

By: Drucilla Dyess
Published: Tuesday, 25 March 2008
model of human growth hormone

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A Stanford University study published in the Annals of Internal Medicine on Monday, March 17th, concluded that muscles created by human growth hormone (HGH) don't perform as well as they appear to. In fact, the treatment may cause impairment. In addition, the artificially added muscle can actually tire athletes and increase their risks for injury.

The Stanford research team performed and analyzed 27 studies of HGH with a total of 303 participants between the ages of 13 to 45. The studies tested the physiological effects of growth hormone compared with an inactive placebo. After taking HGH under medical supervision, the healthy volunteers gained about 5 pounds in weight and though they seemed to have more lean body mass, which could be associated with more muscle, no one showed any increase in muscle strength of their biceps and quadriceps. They were also more likely to suffer from joint pain and carpal tunnel syndrome.

The Stanford researchers also noted hormone-related problems in study participants who were exercising. Some studies showed that those who took HGH generated more lactate, causing muscle fatigue. The fatigue was so great in one study that two cyclists quit a workout. "In growth hormone-treated groups, people think they'll get an energy boost, but we found higher rates of fatigue," said lead investigator Hau Liu, formerly of Stanford and now at San Jose's Valley Medical Center.

Since professional athletes may take HGH dosages up to five times higher than the doses studied by scientists as well as take the dosages in combination with other drugs such as steroids or insulin, the research team advised caution in interpreting the data. The study also did not address whether HGH accelerates athletes' recovery from injury, although this is often a reason for its use.

According to Liu, study techniques could not distinguish between lean solid tissue and fluid mass indicating that much of the muscle increase was due only to fluid retention and not actual tissue growth. This could explain why increases in body mass did not improve strength.

"This study summarizes what we know to date," Liu said. "If we really want to answer the question 'How do you hit a baseball further?' we need to understand how athletes take this and other agents."

Regarding the young and healthy volunteers who took the HGH, Liu stated, "We felt that the risks outweigh the benefits." However, for sick people with proven growth hormone deficiencies, and the elderly, he stated that for them, the benefits of treatment outweigh the risks. Liu went on to say that further work would be needed to truly measure the impact in athletes.

HGH is produced naturally by the body’s pituitary gland to regulate height, muscle and organ growth. A synthetic version of HGH has been approved by the Food and Drug Administration for use by children who suffer from growth disorders or AIDS patients who have lost weight.

The International Olympic Committee, Major League Baseball and the National Football League have banned the use of HGH and United States law prohibits its use for sports enhancement. However, it is very popular among athletes because it is undetectable in tests and can be easily obtained from distributors who sell it illegally over the Internet, as well as through mail order.

A wide range of athletes has been implicated in the illegal use of HGH. The "Mitchell Report" released in December of 2007 identified 89 Major League baseball players who may be using performance-enhancing drugs and many of them have admitted to their use. Even several musicians, such as Timbaland, Wyclef Jean and 50Cent have also been suspected of using HGH to maintain extraordinary physiques.

Medical experts are hopeful that the Stanford study may cause athletes to think twice about risking their careers. Roberto Salvatori, Endocrinologist at the Johns Hopkins School of Medicine, stated, "I think there will be resonance among athletes or athletic teenagers [or] anybody who was thinking about using it, because there really is a lot of underground mythology about it. This may give the ammunition to convince athletes or young kids that it is not really worth using, that it may not have the effectiveness that they think it will have."