Troubling Side Effects Found With Growth Hormones

The growing use of growth and sex hormones to stay youthful in old age carries troubling side effects that could outweigh potential benefits, according to a study in today’s Journal of the American Medical Assn.

The report, which tracked 131 elderly men and women taking growth hormones, said such complications as carpal tunnel syndrome, joint pain, swollen limbs, diabetes and other disturbances in blood sugar regulation.

The study also showed that the hormones had beneficial effects, such as increasing muscle mass and reducing body fat, offering hope that the hormones could improve health in old age.

But for now, the authors said, the side effects are troubling and insufficiently understood. They said the use of the hormones by a growing number of anti-aging clinics may be putting elderly patients at risk.

“We don’t have any proven benefits and we don’t know exactly what the risks are, and have reason to believe they may be substantial -- so how can you prescribe this stuff to people?” said study co-author Dr. Mitchell Harman. He is director of the Kronos Longevity Research Institute, a private research center in Phoenix, and former chief of endocrinology at the National Institute on Aging.

In a rebuttal, the Chicago-based American Academy of Anti-Aging Medicine said in a draft response that the side effects of properly administered therapy are negligible and transient.

Thousands of older people are taking the growth hormone without ill effects, said the society’s founder, Dr. Ronald Klatz, a Chicago-based osteopath and author of such books as “Ten Weeks to a Younger You.” The science behind the anti-aging benefits of the growth hormone is “unassailable,” he said.

As people grow older, their bodies change, losing muscle and bone mass, and accumulating abdominal fat. This is partly because of declines in production of the human growth hormone.

Adding back the hormone seems to help counteract these changes, as reported in a landmark 1989 study on elderly men that helped trigger the growth of anti-aging clinics.

This trend has worried many endocrinologists, in part because people who overproduce the growth hormone (a condition called acromegaly) have increased rates of diabetes, arthritis, high blood pressure, heart disease and possibly certain cancers. There is a concern that elderly people taking the growth hormone might expose themselves to such risks too.

In the JAMA study, researchers led by Dr. Marc Blackman of the National Institutes of Health administered the growth hormone or a placebo to 57 women and 74 men age 65 to 88 for 26 weeks. For some women, the sex hormones estrogen and progestin were added to the mix. Some men received testosterone.

All groups receiving the growth hormone responded with increased lean muscle mass and decreased abdominal fat.

The scientists found that strength and endurance improved only for men taking testosterone and the growth hormone together. This group experienced a “marginally significant” 6.8% increase in muscle strength and an 8.3% increase in cardiovascular endurance. There was no improvement for women in those areas.

It is not clear whether these small muscle and endurance increases translate into real health benefits -- such as a reduced risk of falling, said Dr. Lawrence Frohman, an endocrinologist and professor of medicine at the University of Illinois at Chicago.

Side effects to the growth hormone were common, whether the hormone was taken with a sex hormone or alone. Joint pain occurred in 41% of men taking the growth hormone, and none who were not. Limb-swelling occurred in 39% of women taking the hormone. Carpal tunnel syndrome occurred in 32% of men taking the growth hormone with testosterone.

Abnormal blood sugar levels were also observed in 18 of the 36 men taking the growth hormone, versus only seven who were not. In five of the men, blood sugar levels were in the diabetic range.

Side effects went away when treatment was halted, but the study lasted only 26 weeks. It is uncertain if the use of the growth hormone over a long period would increase the risk of sustained side effects.

The authors recommended that for now, growth hormone use in elderly men and women be restricted to clinical studies.

Dr. Ronald Swerdloff, professor of medicine at Harbor-UCLA Medical Center, said he has noticed impressive changes in the bodies and moods of growth-hormone-deficient patients after they received the growth hormone. He believes there could also be benefits to giving elderly people the hormone, but far more needs to be known before the treatment can be deemed safe for general use, he said.