Your Health by Dr. Rallie McAllister

For most men, growing older means growing better, especially in terms of knowledge, wisdom and patience. On the downside, advancing age is usually accompanied by a slew of not so wonderful physical changes, including weight gain and loss of strength and stamina.

While these changes are often considered a natural part of aging, dwindling levels of the male hormone testosterone are primarily responsible.

In most healthy men, testosterone production reaches an all-time high in the late teens, and levels remain relatively stable for up to two decades. Between the ages of 30 and 40, testosterone levels begin to drop at a rate of about 1 to 2 percent per year.

By the age of 65, testosterone levels may be hovering at the low end of the normal range. The dilemma facing aging men and their physicians is whether to accept the decline in testosterone as a normal phenomenon or to treat it as an illness that requires medical intervention.

For decades, testosterone replacement therapy has been used to treat young men with abnormally low testosterone levels, a condition known as hypogonadism. In recent years, a growing number of middle-aged and older men began taking the hormone to boost waning testosterone levels and to ward off the effects of aging.

Some physicians find this trend worrisome, since no long-term studies have fully evaluated the risks of hormone replacement therapy in older men. Despite a lack of definitive scientific evidence regarding safety, testosterone therapy is growing in popularity: Prescriptions for the hormone doubled between 2000 and 2004.

There's no denying that the results of preliminary research are promising: Supplemental testosterone has been shown to increase lean muscle mass and strength, while it reduces body fat. In a number of clinical trials, men treated with hormone replacement therapy reported enhanced libido, higher energy levels and a greater sense of well-being.

Testosterone replacement therapy can slow the loss of bone mass, reducing the risk of osteoporosis and debilitating bone fractures in elderly men. Although osteoporosis is commonly considered a woman's disease, data from the National Osteoporosis Foundation suggest that nearly 2 million American men suffer from the condition, and another 12 million are at risk of developing it.

In a study published in a 2006 issue of Archives of Neurology, researchers concluded that testosterone replacement therapy appeared to significantly improve the quality of life for elderly men with mild cases of Alzheimer's disease.

Other clinical trials have shown that supplemental testosterone can boost mood, memory and concentration in older men.

Men who experience noticeable declines in energy levels, libido and muscular strength with advancing age may wonder whether their testosterone levels are adequate. Physicians can diagnose testosterone deficiency based on the findings of a complete physical examination and the results of specific blood tests.

For men with abnormally low testosterone levels, treatment has never been easier; thanks to an expanding selection of hormone replacement drugs and delivery systems approved by the U.S. Food and Drug Administration. In the past, men receiving testosterone replacement therapy had to submit to regular injections or have pellets implanted under their skin.

Intramuscular testosterone injections are still used, but more men are opting for daily treatment with testosterone-impregnated patches, worn on the torso, arm or thigh. Testosterone gel, applied daily to the upper arm or shoulder, is another popular method of delivery.

In 2003, the FDA approved a sustained-release testosterone tablet, designed to adhere to the gum just above the front teeth. Used twice daily, the tablets deliver testosterone to the bloodstream by way of the mucous membranes of the mouth.

As with any drug therapy, testosterone replacement is not completely without risk to the patient, and in many cases, the risks can far outweigh any potential benefits. In some men, supplemental testosterone can adversely affect cholesterol levels, which may translate to a higher risk of heart disease.

While testosterone treatment hasn't been shown to cause prostate cancer, it can fuel the growth of an existing malignancy. For men suffering from non-cancerous enlargement of the prostate gland, testosterone replacement therapy can aggravate the condition.

Extra testosterone can trigger excessive red blood cell production in men, increasing the risk of stroke. Other potential adverse effects include acne, mood swings and the development or worsening of male pattern baldness.

Hormone replacement therapy isn't exactly the fountain of youth, but for a small percentage of older men, a little extra testosterone can go a long way toward improving health and happiness.

Rallie McAllister, M.D., M.P.H., is a family physician in Kingsport, Tenn., and author of "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her Web site is http://www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

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