Take Some Testosterone and Call Me in the Morning

by Eugene R. Shippen, MD

With all the media interest in estrogen and women's mid-life health, it is easy to forget that men experience hormonal ups and downs as well. Epidemiological studies suggest that a yearly decline in testosterone levels of 1% to 1.5% loss is normal. From a population perspective, 1% to 1.5% annually doesn't seem like much. But tell one of your patients that he experiences a 10% to 15% loss in testosterone over a 10-year period and it's entirely different story!

Among healthy men, there are three causes of age-related declines in testosterone levels: primary testicular failure, which is relatively rare; environmental and metabolic factors, which are fairly common and correctable; and male hypogonadism, which can be genetic. Since there is no cessation of menses to mark the onset of significant hormonal decline in men, it is the job of the astute clinician to suspect, test for and treat this deficiency.

Male hypo-gonadism, sometimes called "male menopause," has been recognized only recently as a valid medical entity, despite published accounts and clinical descriptions starting in the 1940s, shortly after its identification and synthesis.

The Vicious Cycle
Testosterone may in fact be the single factor that links all age-related degenerative diseases. It is certainly intimately tied to the male cycle of aging. As testosterone gradually declines, lean body mass declines, which reduces the body's ability to burn calories. It is interesting to note that lean body mass is one of the best predictors of longevity. With the wanning ability to burn calories comes an increasing fat mass and a reversal of the muscle: fat ratio.

Fat cells are full of the enzyme aromatase, which converts testosterone into estrogen. Estrogen, in turn has a suppresive effect on the hypothalamic pituitary unit, which leads to less production of testosterone-and the cycle is complete.

CVD Risk ... and More
Testosterone is probably the single most important variable, and for years the most overlooked, for cardiovascular disease. The heart is very dependent on testosterone; in fact, there are more testosterone receptors in the cardiac muscle than in any other muscle.

After an acute myocardial infarction (MI), testosterone production increases. After a healing period, testosterone level may rise again - but it may not if the MI in fact occurred due to a declining level of testosterone . For example, every aspect of the cardiovascular risk factors called Syndrome X-hyperlipidemia, hypertension increased insulin resistance and obesity-is testosterone sensitive. Fibrinogen level, which is far more predictive of cardiovascular disease than lipid levels, is also related to testosterone. In addition, some studies have correlated plaque formation with low testosterone levels.

The connection to testosterone is not limited to cardiovascular disease. Many age-related chronic and even acute diseases are associated with a decrease in production of testosterone, either as result of disease process itself or as a factor in the incidence of disease. Increasing testosterone will improve stamina and muscle mass. Achieving an optimal testosterone level calms the autoimmune system, the inflammatory processes and has powerful neurgenerative effects as well.

Some Treatment Guidelines:

Testosterone is metabolized both in liver and peripherally, and it has a very short half-life. Not only do many enzymes affect it and the tissues; it also is produced in pulse waves that are very difficult to duplicate in treatment modalities.
In treating testosterone deficiency, it is important to keep several strategies in mind:
Because of the body's complex regulatory circuitry, one must boost their production of testosterone before using replacement therapy.
Remember that most primary hormones are prohormones as well as primary hormones.
Try to duplicate the body's natural biorhythms. For men with testicular failure, injections will not accomplish this.
Everyone has a different window. Differentiate between patients who need more or less.
Remember that excess replacement of testosterone results in estrogen conversion.

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