Wednesday, January 20, 2010

Andropause, Low Testosterone and Alzheimer’s Disease

Andropause is a man's version of menopause; however, it does not happen quite as dramatically as what a woman experiences. Hormone changes in men occur gradually over a period of years. In comparison, women experience the cessation of ovulation, which leads to the plummeting of hormone levels, and entry into menopause within a relatively brief period of time. A woman's springboard into menopause is more drastic than what a man experiences; however, that does not diminish the impact that andropause can have.

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What It Is
Andropause refers to age-related hormonal changes in men. Other terms for andropause include late-onset hypogonadism, androgen deficiency of the aging male and testosterone deficiency.

The Decline
A decline in testosterone (and androgen) is not unexpected. By the time a man reaches the age of 90, his testosterone level will have decreased by half. In fact, levels start to decline by 1 percent a year, starting when a man is 30.

Testosterone is Critical
Harvey S. Bartnof, M.D., director of the California Longevity and Vitality Medical Institute, notes that the male sex hormone is important and not just for sexual reasons. He points out that low testosterone levels can result in increased body fat or a beer belly. Fat around the mid-section is linked with heart disease. Decreased circulation, which is called atherosclerosis, is also the result of andropause. Diabetes may occur at this time in a man's life as can osteoporosis, which is porous bone disease, which can lead to fractures.

Types of Testosterone
Testosterone is the principal male sex hormone, but testosterone is also present in females. However, men produce forty to sixty percent more testosterone than women.

In the body, there are two types of testosterone: free and bound. Bound testosterone is attached to sex hormone binding globulins, or SHBGs. However, when bound to sex hormone--binding globulin, the testosterone does not work as efficiently as it can. According to John Hopkins University's Health Alerts, "free testosterone is a form of the hormone that is not bound to a protein in the blood and is therefore available to body tissue." But testosterone in its free form is also related to Alzheimer's disease.

Testosterone and Alzheimer's Disease
Wayne State University Professor Scott Moffat and his university colleagues have confirmed a link between low testosterone and Alzheimer’s disease (AD) in older men.

In this study, investigators evaluated the testosterone levels of 574 men, ages thirty-two to eighty-seven, who participated in the Baltimore Longitudinal Study of Aging (BLSA). They examined “total” and “free” testosterone levels—measured over an average of nineteen years—in relationship to subsequent diagnosis of AD. Launched in 1958, the BLSA is USA's longest running scientific examination of human aging. Researchers there have measured testosterone levels in male participants since 1963.

The research team found that for every fifty percent increase in the free testosterone in the bloodstream, there was about a 26 percent decrease in the risk of developing AD. Although overall free testosterone levels dropped over time, these levels fell more dramatically in those men who later developed AD. In fact, at the end of the study, men who were diagnosed with AD, on average, had about 1/2 the levels of circulating free testosterone as men who didn’t develop the disease. In some cases, the drop-offs in free testosterone levels associated with AD were detected up to a 10 years before diagnosis.

Just as in any other medical condition, a diagnosis is made based upon a patient’s history (symptoms), physical examination, laboratory tests and possibly other additional tests. 

A blood test is the only of the most decisive ways to verify low androgen levels. The symptoms of andropause include insomnia, which is caused by low testosterone levels; shrinkage of your testes; reduced sexual desire; fewer spontaneous night-time erections; lost bone density; reduced strength and muscle bulk; more body fat; tender and swollen breasts (gynecomastia); hair loss, loss of energy and hot flashes, you may, in fact, be in the midst of andropause. Ask your physician to do a blood test to confirm it.

Usually, testosterone is prescribed as a periodic injection (every 7 or 10 days) or as a topical cream or gel, either once or twice daily.  A less commonly-used formulation is pellets implanted under the skin every few months.  Other formulations include skin patches, a small patch used in the mouth on the gums and a sublingual (under the tongue) tablet.  There are advantages and disadvantages and benefits/ risks for each of the formulations. Oral testosterone as a sole medication is not available in the US. 

Side Effects
As with any treatment, there are potential side effects. They are often manageable. However, if a side effect cannot be managed or begins to outweigh potential benefits, then a decision may be made to stop treatment. 

Side effects include: more natural oil on the skin (particularly the head) that when excessive may lead to oily skin or hair and even acne; increased red cell counts (treatable or avoidable); excessive libido; and possible prostate growth. 

The prostate issue in testosterone therapy is a controversial one. It appears that the hormones that testosterone converts into (DHT and probably estradiol) are the ones involved in prostate growth.  Therefore these other hormones also generally require monitoring and natural supplements or prescriptive medications may be used to keep those hormones in a normal range.  Regular monitoring of the PSA (prostate specific antigen) blood test, red cell counts and examination of the prostate is necessary. A man who has had a history of prostate cancer or breast cancer (yes, men do sometimes get breast cancer) has a relative contraindication to (should not take) testosterone replacement therapy. 

However, if a man with either of those cancers has been cured and enough time has passed, he may be a candidate for testosterone replacement. DHT (made from testosterone) may induce scalp hair loss in susceptible men, unless the DHT is blocked or inhibited with specific treatments. A few men are susceptible to subtle, female-type breast appearance, but this is preventable and treatable with specific therapies.  Some men may notice a slight decrease in the size of their testicles, but this can be avoided with specific treatments, if necessary. The decrease occurs because of a feedback loop that shuts off the normal brain signal to the testicles. This same mechanism may decrease sperm counts and decrease fertility—if a man still desires to father a child, there are treatments to allow for normal sperm counts.  

Sometimes, testosterone can worsen “sleep apnea,” a condition whereby breathing temporarily stops during sleep—this is more likely to occur in men who are overweight or obese.  In some men, testosterone may decrease the HDL (“good”) cholesterol. This decrease is counterbalanced by increased clearance (decrease in blood level of) of total cholesterol. Low HDL can be treated with lifestyle intervention and/or prescriptive and non-prescriptive medication. When testosterone levels are within normal limits, “rhoid rage” (excessive anger) does not occur—but may occur when levels are too high or “supraphysiologic,” as when it is abused by some “body-builders.” Oral testosterone is not available in the US as a sole drug, and certain types can cause liver problems. 

Sources and Additional Information:
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