Growth Hormone: The Secret of Youth or a Cautionary Tale?

By Bonnie Desimone

SIXTEEN years ago, a small-scale study of human growth hormone therapy among older men opened a large debate in the medical community over whether it could stave off physical decline.

Since then, the arguments on both sides have become only more passionate. Demands for prescriptions have increased, as has online demand for both legitimate and fraudulent forms of the product, known as HGH -- eventually growing into an estimated $1 billion global market.

Because evidence shows potentially harmful side-effects, most mainstream doctors caution against using HGH, except in strictly delineated cases. Other doctors say it is an effective anti-aging weapon.

''This is an experiment going on with unsuspecting people who are living on the hope that this will somehow help them retain their youth and vigor,'' said Dr. Robert N. Butler, a professor of geriatrics at Mount Sinai School of Medicine in New York.

Like many experts, Dr. Butler contends that proper nutrition and regular exercise, especially strength training, will yield equal or better results in building muscle mass and increasing well-being among older patients without the pitfalls of HGH, which can cost up to $20,000 a year and is rarely covered by insurance.

Yet doctors like Dr. Eric Braverman, director of PATH Medical, a center for integrative medicine in New York, defend the use of HGH at low, carefully supervised levels. One of his patients, an 82-year-old retired executive from Long Island, who requested anonymity for privacy reasons, said that daily HGH injections over the last 13 months had repaired some of the damage he incurred from congestive heart failure and overmedication for high-blood pressure.

''I can't walk fast, but I can walk 40 blocks now with no trouble,'' he said. ''I've had virtually no side-effects.''

Dr. Braverman predicts that HGH will become more widely prescribed. ''I am convinced that it is a core dimension in dealing with the effects of aging,'' he said. ''I have hundreds of patients with experience, and it's rare that they have side-effects. The real danger is that these things are being sold over the Internet.''

On that issue, both sides agree.

Human growth hormone is produced and released by the pituitary gland at the base of the brain. The hormone stimulates the liver to produce insulin-like growth factor, or IGF-1. That substance, in turn, spurs normal growth in bones and tissues.

HGH has long been prescribed for children whose growth is affected by kidney disease or other conditions. The hormone has also been used to treat muscle-wasting diseases caused by AIDS.

Growth hormone was harvested from cadavers until the mid-1980's, when researchers began to synthesize it using recombinant DNA technology. Although the process was expensive, it opened up more commercial and black-market opportunities.

The catalyst for the HGH debate was a study published in The New England Journal of Medicine in 1990. A dozen healthy men, ages 61 to 81, were given HGH injections for six months. Among the results: lean body mass increased and body fat decreased; and blood sugar and blood pressure increased. An accompanying editorial called the study ''an important beginning,'' but raised ethical questions and said more research was needed.

In 2003, The New England Journal of Medicine published an editors' note deploring the use of that 1990 study in ''potentially misleading e-mail advertisements.''

Recent studies have confirmed that the hormone can benefit people with HGH deficiencies, but doctors disagree on how to define and test that condition. The hormone is only effective by injection, doctors agree. It can increase lean body mass and bone density, and improve mood.

HGH doesn't necessarily increase strength, however, and can raise the risk of diabetes and cause swelling, carpal tunnel syndrome and muscle pain. Some researchers fear that HGH could promote tumor growth but no direct causal link to cancer has been established, said Dr. Evan Hadley, director of the Geriatrics and Clinical Gerontology Program at the National Institute on Aging.

Dr. Hadley said that research is being conducted as to whether HGH could help stabilize or reverse declining cognitive function.

In cyberspace, HGH is promoted as a way to shed weight, build muscle, smooth wrinkles, promote healing, relieve chronic pain and restore youthful energy.

These promises can be seductive for maturing baby boomers. ''Their expectations of physical activity are much, much higher,'' said Dr. Paul Y. Takahashi, a geriatrician and assistant professor of medicine at the Mayo Clinic in Rochester, Minn.

Many supplements advertised online do not contain any growth hormone, falsely claim to stimulate its production or come with unsubstantiated statements about its benefits.

Heather Hippsley, a lawyer and assistant director of the division of advertising practices at the Federal Trade Commission, said the agency was trying to combat fraudulent marketers by sending warning letters to Web sites and getting misleading infomercials off the air.

Last year, the agency obtained a federal court order compelling two Florida companies to pay up to $20 million to consumers who had bought HGH ''enhancers'' online.

The debate over HGH therapy escalated last fall as several prominent researchers published a commentary in The Journal of the American Medical Association charging that most prescriptions for HGH in the United States may be illegal. They wrote that the federal Food, Drug and Cosmetic Act prohibits prescribing HGH to treat anti-aging in the broad sense, as opposed to specific hormone deficiencies resulting from pituitary disease.

The American Academy of Anti-Aging Medicine, an advocacy group that says it has more than 17,000 doctor members, wrote a response on its Web site: ''At no time has Congress evinced any intent to restrict ethical physicians from prescribing HGH to mature or elderly adults for medical reasons within their sound judgment.''

Amid the crossfire, most mainstream doctors advise caution. Dr. Takahashi wrote an article for the Mayo Clinic's Web site outlining the risks and approved uses of HGH, concluding that ''more study is needed.''

Conservative approaches to HGH therapy are being influenced by an evolution of thought on estrogen replacement therapy, Dr. Takahashi said. Once viewed as a remedy for postmenopausal changes, estrogen is now linked to increased cancer risk.

''We learned a lot from that experience,'' he said. ''It's possible that human growth hormone could allow people to be a little bit better for a little bit longer. The question is, at what price? I think it could be a pretty high price.''

Source: The New York Times