Human Growth Hormone Has Its Benefits, But Deadly In High Doses
Caution urged, despite study that says it can add muscle massMar 31, 2005 | Charlotte Observer
Until 1990, the main reason someone took human growth hormone was to grow taller.
But a study published that year found raising HGH levels in healthy men ages 61 to 81 led to increased muscle mass and decreased fat tissue.
Since then, some doctors have touted HGH as a fountain of youth for an aging population. And some athletes have used it to enhance sports performance.
But those uses remain controversial.
At extremely high doses those thought to be used by athletes HGH can cause major health problems and shorten life.
"Large doses of growth hormone are clearly toxic," said Dr. Mitchell Harman, director of Kronos Longevity Research Institute in Phoenix and a growth hormone researcher.
High doses of HGH can cause acromegaly, a disease characterized by enlarged hands, feet and foreheads, abnormal bone growth, arthritis and enlargement of the heart. People who have it die young and usually of heart disease, Harman said.
"They get hypertension. They get diabetes. They get in trouble."
History of HGH
Human growth hormone is produced by the pituitary gland in the base of the brain. It regulates growth and influences metabolism. Levels peak in late adolescence, then decline.Until the mid-1980s, growth hormone was used almost exclusively to treat dwarfism in children. Harvested from cadavers, it was scarce and expensive.
In 1985, the Food and Drug Administration approved a synthetic growth hormone, eliminating the scarcity problem. And then came the 1990 study.
Dr. Robert Butler, president of the International Longevity Center in New York, said the study was well done but involved only 12 men over six months.
"Long-term use is another matter about which we don't know very much," he said.
Butler and others warn that doctors don't know enough about the possible dangerous side effects, such as diabetes and cancer.
Human growth hormone is not approved for anti-aging or athletic performance enhancement, but once a drug is approved for one use, doctors are allowed to prescribe it for any reason if they feel patients will benefit.
"It's not illegal. It's called off-label use," Butler said. "It might be subject to some ethical discussion. There may not be any true indications for it other than the aspiration to be a winner."
High levels hard to detect
For athletes to get the desired benefits, they would have to take enormous doses, Harman said.
But abnormal levels are not easy to detect. "You can only measure excessive HGH if they've taken it in the last 12 hours or so," he said. "It dissipates."
HGH is on the NFL's list of banned substances, but the director of the league's testing program has said it can't test for it yet.
Instead of measuring HGH, many doctors measure insulin-like growth factor that is produced by the liver in response to HGH. But that isn't totally reliable, either, because normal levels vary from person to person.
Dr. John Lacouture, a Charlotte internist who specializes in anti-aging medicine, said he has changed his mind about what he once thought were anti-aging benefits of HGH.
"It increases strength and energy and muscles. But maintaining the level of growth factors throughout life at high-normal, I'm not sure that's a good strategy for successful aging.
"You just have to be careful. These are very, very powerful agents, for good and for bad."