Testosterone and You

In the male body, testosterone is the primary male sex hormone or androgen present in the blood. At puberty, testosterone is the hormone that is primarily responsible for producing and maintaining the typical male attributes including growth of facial and pubic hair, deepening of the voice and increase in muscle mass and height. Apart from the vital role that testosterone and other androgens play during puberty in stimulating the development of male secondary sexual characteristics and their maintenance thereafter, they have multiple other physiological and biological effects. These include the promotion of red blood cell production; the stimulation of bone growth; and the suppression of adipose (fat) tissue formation. Testosterone also has positive effects on mood, cognitive ability and behavioral effects such as mediating sexual behavior.

Low testosterone, also called Low T or Hypogonadism, is a treatable clinical condition defined by abnormally low testosterone levels. Hypogonadism affects approximately four to five million American men. However, it is estimated that only five percent of affected men currently receive testosterone replacement therapy.

Testosterone deficiency can be diagnosed by a simple blood test performed by your physician. The normal range for total testosterone in men is generally between 300 nanograms per deciliter (ng/dL) and 1,000 ng/dL.

Hypogonadism is the medical term frequently used for decreased functional activity of the gonads. The gonads (testis or ovaries) produce hormones (testosterone and estradiol). A deficiency in the production of these hormones can be classified into primary and/or secondary hypogonadism. Primary hypogonadism is essentially testicular failure. It is characterized by low serum testosterone and high LH (Luteinizing hormone) and FSH (Follicle stimulating hormone) concentrations. It can result from testicular injury, tumor, or infection; genetic defects affecting testicular development (e.g. Klinefelter syndrome), as well as chemotherapy, radiation or alcohol abuse. In secondary hypogonadism, defects in the pituitary gland, located in the brain, can result in low testosterone levels. It's also associated with low or low-normal FSH and LH levels. Patients with secondary hypogonadism can have their fertility restored, whereas those with primary hypogonadism resulting from testicular failure cannot.

The best management of testosterone includes confirmation of the diagnosis and prognosis, therapeutic intervention, and consideration of future fertility prospects. Several published studies have shown the beneficial effects on quality of life by normalizing testosterone levels with testosterone replacement therapy. Most importantly, normalizing testosterone levels may reduce the risks of developing serious medical conditions. There is mounting evidence linking low testosterone levels to long-term medical conditions such as metabolic syndrome, type II diabetes, coronary heart disease, osteoporosis and depression.

One of the fears of testosterone replacement is the supposed link between testosterone and the development of prostate cancer. Recent epidemiological and clinical studies suggest that there is no association between testosterone levels and risk of prostate cancer. There is no evidence to date to suggest that low testosterone levels are protective against prostate cancer and that normal levels increase the risk of prostate cancer. Interestingly enough, testosterone levels decline with age, while prostate cancer incidence increases with age.