Impact of Testosterone Levels in Aging Men - Life Extension

Optimizing Testosterone Levels in Aging Men - Life Extension

Testosterone Supplements — An Undeserved Shady Past

The medical community has been slow to recognize the consequences of low testosterone levels in aging males and, in fact, wrongly believes that restoring youthful levels of testosterone is dangerous and unwarranted. Back in the mid-1900s, some drug companies sold a synthetic and chemically altered testosterone called methyltestosterone.

They pawned this chemical off as real testosterone, even though it does not naturally exist in the human body. After several years on the market, some men taking this particular chemical developed liver cancer.4,5 “Testosterone therapy” was then declared to be dangerous, and research on testosterone fell by the wayside.

While testosterone is a member of the group of compounds known as “anabolic steroids,” it is different and less potent than the illegal synthetic compounds that have been taken in excessive doses and abused. Beginning in the late 1980s, overambitious and unscrupulous professional athletes began taking illegal anabolic steroids to gain an unfair competitive edge. Unfortunately, this abuse has wrongly clouded the important health benefits of prescribing testosterone therapy to correct its decline associated with aging and other diseases. In response to the sports abuse issue, federal law has made testosterone a controlled substance just like narcotics and amphetamines. Illegal-use penalties can be severe for any doctor who improperly prescribes anabolic steroids.

Although this has made some doctors reluctant to prescribe testosterone, medical prescribing of the hormone jumped by 50% in four years from 2001 to a total of 2.3 million prescriptions in 2005.6 Some physicians do therefore appear to be increasingly recognizing the consequences of low testosterone levels in aging males.

Evolving Opinions on Testosterone Replacement

In November 2003, the Institute of Medicine declared that “existing scientific evidence does not justify claims that testosterone treatments can relieve or prevent certain age-related problems in men.” Most age-management physicians today strongly disagree with that statement. There are hundreds of studies in the medical literature showing the health benefits and safety of testosterone therapy. n 2007, Drs. Miner and Seftel.  I published a review of the medical literature on testosterone since the 2003 Institute of Medicine Report.7 The summary of their article states:

“Recent studies have demonstrated that hypogonadism [low testosterone] in men may be more prevalent than previously thought, is strongly associated with metabolic syndrome, and may be a risk factor for type 2 diabetes and cardio-vascular disease. Clinical studies have shown that testosterone replacement therapy in hypogonadal men improves metabolic syndrome indicators and cardiovascular risk factors. Maintaining testosterone concentrations in the normal range has been shown to contribute to bone health, lean muscle mass, and physical and sexual function, suggesting that testosterone replacement therapy may help to prevent frailty in older men. Based on current knowledge, testosterone replacement therapy is unlikely to pose major health risks in patients without prostate cancer and may offer substantial health benefits.”

Testosterone and Cardiovascular Health

Let’s take a closer look at what the medical literature says about the specific benefits of testosterone restoration. Many studies have shown an association between low testosterone levels and a higher prevalence of coronary artery disease8-10 and aortic atherosclerosis.10 Lower testosterone levels are also associated with reduced pumping ability of the heart.9
 
Recent studies suggest that testosterone-replacement may improve the symptoms of coronary artery disease. A placebo-controlled crossover study in men with ischemic heart disease and low testosterone levels reported that exercise time and the time to development of ischemic changes on a treadmill test were both increased with testosterone-replacement therapy.11

Another placebo-controlled study found that 12 weeks of oral testosterone-replacement therapy improved the ability of the brachial artery to dilate in men with coronary artery disease,12 suggesting an improvement in endothelial function. These and other medical studies provide mounting evidence of the clinical benefits of testosterone-replacement therapy in men with coronary artery disease.

Testosterone and Insulin Resistance/ Diabetes

Type 2 diabetes is reaching epidemic proportions in America today. Likewise, metabolic syndrome—a condition marked by insulin resistance that dramatically increases the risk of heart disease and diabetes—is becoming increasingly more prevalent.

Growing research suggests that low testosterone levels may be intimately linked with insulin resistance and its related conditions of metabolic syndrome and diabetes.13,14 Recent research suggests that between 20% and 64% of men with diabetes have low testosterone levels; older men appear to be particularly susceptible.15 Likewise, low serum testosterone is common among men with metabolic syndrome, and some scientists have proposed that low testosterone might serve as a prognostic tool for early detection of the condition.14

Restoring testosterone to youthful ranges may confer a wide array of benefits to men affected by type 2 diabetes. The reported benefits of testosterone administration in these men include improved glucose homeostasis (balanced sugar levels), reduction in abdominal fat, and improved erectile function.16 Likewise, scientists believe that testosterone replenishment may help reverse some of the key biochemical abnormalities that underlie metabolic syndrome, such as insulin resistance and central obesity.14,15

What You Need to Know: Optimizing Testosterone Levels in Aging Men

Testosterone, the chief male hormone, is essential for libido and erectile function, and plays a crucial role in mood, energy, bone health, and body composition. Testosterone levels decline with age, usually beginning in a man’s mid-30s. Diminishing testosterone levels have been linked with disorders such as depression, fatigue, obesity, and cognitive decline. Low testosterone levels increase the risk of coronary heart disease as well as all-cause and cardiac mortality. Restoring testosterone to youthful levels offers men a wealth of health benefits, including benefits for heart health, body composition, mood, and memory. Bioidentical testosterone has not been found to have adverse effects on the healthy prostate gland—in fact, it may help improve prostate symptoms in men with low-normal testosterone levels. Testosterone therapy is contraindicated in men with prostate cancer. Regular blood testing can help you and your physician decide if testosterone therapy is right for you. Optimizing testosterone levels requires a multi-pronged approach that includes optimal diet, proper nutrition, nutritional supplements, exercise, and bioidentical testosterone, if necessary.

Testosterone and Body Composition

With the obesity epidemic raging and its tremendous impact on the overall health of our nation’s population, integrative physicians are particularly interested in the role testosterone plays in body composition. Testosterone appears to affect fat cell metabolism and fat loss in several ways through:

• Inhibiting fat storage by blocking a key enzyme called lipoprotein lipase that is necessary for the uptake of fat into the body’s fat cells. When fat cells are exposed to testosterone in a test tube, the activity of lipoprotein lipase is dramatically reduced.
  
• Stimulating fat burning by increasing the number of certain receptors on the fat-cell membrane that release stored fat.17
  
• Increasing insulin sensitivity and improving lipid and insulin metabolism, while enhancing growth of muscle fibers and decreasing fat deposits.

All of these effects benefit body composition by promoting lean body mass and reducing fat mass.18,19
 
In a landmark study out of Sweden in 1991, researchers gave a group of overweight men supplemental testosterone for six weeks.20 After this time, they found the activity of the fat-storage enzyme lipoprotein lipase to be dramatically reduced in abdominal fat tissue. Waist and hip circumference also decreased in 9 of the 11 men.

Furthermore, a recent review highlights numerous placebo-controlled trials that have demonstrated both significant increases in lean body mass and decreases in fat mass after varying courses of testosterone supplementation in older men.21 In these studies, the greatest favorable changes in body composition were seen in participants with low baseline testosterone levels who received testosterone therapy for a period in excess of 12 months.

Testosterone and the Prostate

A common misconception among physicians is that testosterone administration adversely affects the normal prostate. This idea is not supported by the medical literature. A 2002 study indicates that testosterone is actually beneficial for the prostate gland in the vast majority of cases. In this study, researchers looked at multiple parameters, including prostate volume, prostate-specific antigen (PSA) levels, and lower urinary tract symptoms in a group of men with low or low-normal testosterone levels.22 Of the 207 men studied, 187 responded favorably to testosterone treatment. These positive responders all showed improvement in almost every parameter measured: their prostate glands all decreased in size, PSA was lower, and urinary symptoms such as frequency, urgency, dribbling, and getting up at night to urinate all improved.

In a separate recent study that looked at a similar group of men, the authors observed that “No treatment-related change was observed in prostate histology, tissue biomarkers, gene expression, or cancer incidence or severity. Treatment-related changes in prostate volume, serum PSA, voiding symptoms, and urinary flow were minor.”23

On the question of whether testosterone therapy causes prostate cancer, the answer clearly appears to be no. In a landmark review article published in 2004 in the New England Journal of Medicine, the authors report “there appears to be no compelling evidence at present to suggest that men with higher testosterone levels are at greater risk of prostate cancer or that treating men who have hypogonadism [low testosterone] with exogenous androgens increases this risk.”24 However, since testosterone stimulates cell growth, it is possible that it can accelerate the growth of an existing prostate cancer. Cancer-screening tests such as a PSA test are necessary before replacement therapy. Testosterone-replacement therapy is contraindicated in men with known prostate cancer.

The Importance of Blood Testing

The most efficient way for me (or other doctors) to prescribe the proper dose of low-cost individually compounded testosterone cream is for patients to bring their recent blood test results to my office during the initial visit. Life Extension’s comprehensive Male Blood Test Panel provides the biochemical data I need to help safely restore testosterone to youthful ranges, while suppressing excess estradiol if necessary. The Male Blood Test Panel can be ordered by calling 1-800-208-3444. I encourage men over age 35 to have this comprehensive blood test and evaluation performed annually. Life Extension members who reside in the Southern Utah area are welcome to call my office at 435-688-8582 to schedule an appointment for a medical consultation.

Testosterone and Depression

Depression is a leading cause of disability worldwide. In a recent study of 3,987 older men in Australia, researchers found that those with depression had significantly lower testosterone concentrations than men without depression.25 The authors suggested that older men with depression may benefit from systematic screening of testosterone levels and testosterone supplementation where appropriate. In my own practice, I have seen both younger and older men with low testosterone levels and depression improve remarkably after testosterone supplementation. Other studies have shown an improvement in depression scores with testosterone therapy in patients with depression who are unresponsive to conventional treatments.26,27 Further research in this area is ongoing.

Testosterone Improves Cognitive Abilities

Testosterone supplementation clearly seems to be beneficial for proper male mental and verbal function. Several studies have shown that decreased serum testosterone levels appear to adversely affect verbal memory in healthy young men. Short-term testosterone administration exerts a beneficial effect on spatial and verbal memory and enhances cognitive function in healthy men.28-31

Management of Low Testosterone Levels

Optimizing testosterone levels in men requires a multi-faceted approach that includes proper lifestyle, nutrition, nutritional supplements (such as lignan and plant extracts),32,33 dietary modifications, and exercise, as well as testosterone supplementation and other prescriptive approaches when indicated.
Initially, a medical history and physical examination should be performed, along with a blood-testing panel that includes not only testosterone levels, but also other important parameters such as fasting glucose, PSA, estradiol, and complete blood counts (CBC). It is important to work closely with a knowledgeable physician who is readily accessible and who can adjust treatment as needed. Careful, thoughtful optimization of testosterone levels with a comprehensive evaluation and treatment plan can result in dramatic improvements in one’s overall health and well-being.

For men who no longer produce enough testosterone, an experienced doctor can prescribe a topically applied cream to restore testosterone to youthful ranges. These testosterone creams usually come in delivery systems that enable the precise amount of this hormone to be applied to the skin each day for absorption into the bloodstream.

The reason testosterone cream is used as opposed to tablets is that the oral ingestion of testosterone can result in rapid degradation in the liver and wildly inconsistent blood levels. A testosterone cream, on the other hand, gradually releases into the bloodstream, which is more analogous to the way testosterone is naturally secreted each day by the testicles of younger men.

Compared with brand name testosterone topical drugs, consumers can save more than 85% by using natural testosterone cream made by a compounding pharmacy. For example, the name brand Androgel® cream costs around $225 for a month’s supply. The identical amount of natural testosterone can be obtained from a compounding pharmacy for less than $25 a month. For those patients in whom a cream is not the best choice, testosterone injections can be prescribed.

Follow-up blood testing 30-60 days later is important to ensure that PSA, estradiol, and other blood markers stay in normal ranges. Some men will aromatize (or convert) testosterone into estrogen, which necessitates the use of a drug like Arimidex® or nutrient-lifestyle changes to inhibit excess aromatase activity.

If you have any questions on the scientific content of this article, please call a Life Extension Health Advisor at 1-800-226-2370.