Early Show Medical Correspondent Dr. Emily Senay explains that the growth hormone is produced naturally by the pituitary gland, and levels decline as we age. The question has been whether or not restoring and maintaining youthful levels of growth hormone can stave off some of the negative effects of aging, such as decreased muscle mass and strength, increased body fat, thinning of the bones and a decline in cardiovascular endurance.
A study more than a decade ago suggested this was the case. Since then, a whole industry has cropped up around the use of human growth hormone as an anti-aging supplement.
A new study this week in the journal of the American Medical Association showed that the benefits of growth hormone therapy come with a high price. Dr. Senay says researchers conducted a study in older men and women to study the effects of growth hormone therapy alone and in combination with the sex hormone testosterone in men and estrogen and progesterone in women.
Dr. Senay says the good news is that older men and women taking human growth hormone and sex hormones increased muscle mass, decreased fat and improved aerobic capacity.
But while muscle mass increased, strength did not, which researchers say suggests a cosmetic effect that changes the shape of the body without improving function.
Also, growth hormone causes 40 percent of men and women to experience swelling, arthritis-like joint pain, carpal tunnel syndrome and an increase in glucose intolerance and diabetes.
The side effects went away a few weeks after the hormone treatment was halted, but, Dr. Senay says, these results are very worrying. The study lasted only a little over six months, so it's uncertain if the use of the growth hormone over a long period would increase the risk of sustained side effects.
If you take or are thinking of taking growth hormone, Dr. Senay recommends you consult your doctor. Human growth hormone does have clinical uses other than as an anti-aging treatment. For some the benefits may outweigh the risk. However, the author of the study recommend growth hormone only be used for anti-aging research in elderly men and women as part of a clinical trial.
Dr. Senay says evidence of the anti-aging benefits of human growth hormone is tantalizing, but the latest study is another example of the importance of thorough scientific evaluation before we jump to any conclusions about the benefits or risks.
The promise of hormone therapy or any treatment needs to be proven over time.