Sunday, October 17, 2004

The Dangers of High Testosterone

Moose Life can be stranger than fiction.

Much has been written - and considerable media attention given - to the benefits and risks of estrogen replacement therapy, but considerably less attention has been directed at testosterone replacement. Yet androgen replacement therapy is becoming increasingly common, as improved delivery systems have been developed.

Low testosterone is common in aging men, although there is not a uniform sharp decline as seen in women at menopause. The symptoms are variable, but include fatigue, decreased libido, difficulty with erections, weight gain and loss of muscle mass.

Testosterone replacement has been available for many years, but was limited by less-than-ideal delivery systems. Oral replacement is easy and convenient, but most of the testosterone is metabolized by the liver on its way out of the intestine, resulting in low blood levels and higher risk of liver function abnormalities. Injectable testosterone bypasses the liver and achieves good blood levels, but requires frequent injections, typically every 1-3 weeks. Skin patches were developed in the early nineties, but have been plagued by a high incidence of skin irritation and the need (with some systems) to apply the patch to the scrotal area - not a crowd-pleaser, to be sure. The recent development of topical gels - Androgel and Testim - have revolutionized androgen replacement, providing excellent blood levels with very low risk of skin irritation or other side effects.

Testosterone replacement in men with low serum levels provides many benefits, including improved energy, strength, and libido. Preservation of bone mass and muscle mass are also seen. The downside risks appear to be modest, and include weight gain, sleep apnea, and an increased red blood cell count. There is also much concern about long-term effects on the prostate, including an acceleration of benign enlargement or an increased risk of prostate cancer. To date, however, studies indicate that prostate-related risks do not appear to be of great concern, although long-term monitoring will continue.

One other risk is of great concern to researchers, however: the risk that high testosterone levels may cause recipients to become high-strung. Consider the following report from Alaska:

In one of those only-in-Alaska stories that will shock even the sourest of sourdoughs, a trophy-sized bull moose was accidentally strung up in a power line under construction to the Teck Pogo gold mine southeast of Fairbanks. The moose apparently got its antlers tangled in electrical wire before workers farther down the line pulled the line tight about two weeks ago.

The moose was suspended 50 feet in the air when workers, recognizing something was wrong, backtracked and found it...

The prevailing theory is that the moose came across the sagging and swaying wires and, in a testosterone-filled moment, decided to challenge the power line to a fight, as bull moose are known to do during the rut, or mating season.

"My guess is he was in full rut and probably seen that line moving out there," and decided to fight, said Marvin Pickens, line construction manager for City Electric in Anchorage.

I am now counseling my patients to avoid high tension electrical wires at the initiatiation of testosterone replacement therapy. I know I will be sleeping better since informing patients of this risk.