Testosterone replacement and the aging male

I recently read the following about testosterone and testosterone replacement  “Last summer I took Bruno, my ten-year-old cairn terrier, to the vet for his annual check-up.  “Wow, he has some energy level for an older dog,” commented my vet as he watched Bruno dart around the exam room. My vet started to examine Bruno. “Aha”, he exclaimed. “He’s intact. That’s why he’s still so quick moving and trim. It’s all that testosterone.”

The Vet’s findings are similar to what we find in men. Adequate testosterone levels benefit the aging male. Over the last ten years, prescriptions for testosterone for men over forty have tripled. Testosterone is essential for maintaining muscle and lean body mass, strength and energy levels, fertility, libido and sexual performance. It is needed to maintain normal bone density and prevent osteoporosis. It also positively impacts cognitive function and mood. Unfortunately for men, testosterone progressively declines as they age. Sometimes to levels low enough to impair the numerous functions listed above, leading to adverse health conditions and significant changes in quality of life. So it is easy to see why healthcare providers and their aging male patients would consider testosterone replacement therapy to reverse symptoms related to low testosterone and restore better quality of life.

Several recent studies, however, indicate that testosterone replacement therapy may not be as beneficial to the aging male as originally thought. We need to consider the balance between the risks and benefits.  Their findings link testosterone replacement therapy to an increase in cardiovascular problems. The New York Times and several other national news outlets ran features last month highlighting the findings of a recent study that showed a correlation between testosterone replacement therapy and increased cardiac risk, setting off a bit of a frenzy over the need to better scrutinize how and to whom this medication should be dispensed. There is also discussion over the need for pharmaceutical companies to put a warning label on testosterone replacement therapies and their relevant advertising material, and for doctors to have patients sign a consent indicating an awareness of the potential side effects of testosterone prior to being prescribed this drug.

So how concerned should you be if you are currently on testosterone replacement therapy, or you are experiencing symptoms of low testosterone and are considering discussing testosterone replacement therapy with your health care provider? Will testosterone replacement therapy increase your risk of having an adverse cardiac event?

The study receiving so much recent media attention was funded by the National Institute of Health (NIH) and was published in the journal PLoS ONE. It found that men over the age of 65 had double the rate of heart attacks within the first 90 days of starting testosterone. Men younger than 65 with a history of heart disease had triple the rate of heart attacks within the first 90 days of starting testosterone. Men younger than 65 with no history of heart disease showed no increased risk of heart attack.  Other studies have also produced similar findings. None of these studies have been able to demonstrate specifically how testosterone is causing adverse cardiovascular incidents. Some are suggesting increased physical activity elicited by the physical improvements gained from testosterone replacement therapy is placing too much stress on the cardiovascular systems of men already at risk. However, if you are over 65 or have a history of cardiovascular disease, testosterone replacement therapy may not be for you.

Another source of concern is the growing number of health clinics that cater to the needs of men interested in extending the vigor and virility of youth into old age with the help of testosterone replacement therapy.  Many of these “male rejuvenation” clinics are billing testosterone as a panacea for all that ails the aging male. These clinics are prescribing testosterone without properly screening for this condition and without properly following up with those patients given prescriptions and refills.  Testosterone replacement therapy benefits many aging men, but it is not for all.  Like all medications, testosterone can pose health risks if prescribed to men who do not need it or have pre-existing conditions that contradict it.

Because of the steep increase in the number of prescriptions being written for testosterone, as well as the number of clinics actively marketing testosterone replacement to aging men, the Endocrine Society updated its clinical practice guideline in 2010 to provide a better protocol for evaluating and treating patients with low testosterone.

If you are currently on testosterone replacement therapy (TRT) or considering seeing a healthcare professional about starting it, your initial and follow-up evaluations should adhere to the Endocrine Society’s guidelines.  A healthcare professional should never, ever prescribe testosterone based solely on a patient having symptoms of low testosterone. Your initial examination should include a serum (blood) sample evaluated by a reference lab using a standardized method for testosterone measurement. Initial blood tests often include a total and free testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), prostate specific antigen (PSA), prolactin, and hematocrit (measurement of red blood cells). The sample should be drawn between 7:00am and 11:00am particularly for men under 50, as testosterone levels are highest in the morning.

Due to the lack of standardization in testosterone measurement there is not a level below which testosterone is considered ‘low’.  However, a total testosterone level below 300 ng/dl is usually considered the lower limit of normal.  If your total testosterone level is low, evaluating hormones secreted by the pituitary, LH and FSH will help your healthcare provider determine if the cause is impaired production in the testes (primary hypogonadism) or a problem with the hypothalamus and/or pituitary (secondary hypogonadism). If secondary hypogonadism is suspected, additional testing should be done to determine the cause. If your total testosterone level is low or borderline-low, bone mineral density should be evaluated with a DEXA scan to determine if you have decreased bone density (eg osteopenia or osteoporosis).

A clinical diagnosis of low testosterone based on symptoms and blood work demonstrating low serum testosterone makes you a good candidate for TRT. However your healthcare provider might not suggest TRT if:

  1. You are 65 years of age and older.
  2. You have a history of cardiovascular disease.
  3. You have prostate cancer or a PSA level above 4 ng/ml. (TRT can stimulate the growth of prostate cancer in men with prostate cancer.)
  4. You have severe lower urinary tract symptoms.
  5. You have who have a history of breast cancer.
  6. You have hematocrit above 50%. (TRT stimulates the production of red blood cells. Excessive levels can cause formation of blood clots.)
  7. You have severe sleep apnea. (Severe sleep apnea might be a sign of cardiovascular disease.)
  8. You are concerned about your fertility. (TRT impairs sperm production in testes.)

Once you have started testosterone replacement therapy, your healthcare provider should monitor your progress. You should be evaluated every three to six months to determine if your symptoms are improving. Your serum testosterone level and several other hormones should be measured, and the goal should be to maintain a testosterone level in mid-normal range (ie, 400 to 600 ng/dl). You should be assessed for any adverse effects (cardiovascular disease, PSA/prostate cancer, hematocrit/erythrocytosis). You bone density should be re-evaluated by DEXA scan every one to two years.  Your healthcare provider should not be refilling your prescription without doing this type of periodic assessment.

Before I end this blog, I want to mention that life style interventions have been shown to improve testosterone levels. Studies show there is a link between obesity and low testosterone. Men who are overweight tend to have lower testosterone levels than men who are normal weight. Weight loss, improved diet, and exercise have been shown to boost testosterone levels.

Testosterone replacement therapy, when prescribed and monitored properly, has been proven to be safe and effective for men over forty with low testosterone. It has been shown to improve energy level, libido, muscle and bone loss, and mood. Studies have shown it can lower blood pressure and blood sugar and can improve cholesterol levels.  Studies also demonstrate that men with normal testosterone levels have a 40% lower death rate compared with men who have low testosterone levels.  If you think you suffer from low testosterone, testosterone replacement therapy could be of great benefit. Just make sure you are evaluated and monitored by a physician who is experienced with hormone replacement therapy in men.

References:

 Bhasin S, Cunningham GR, et al. Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2010 Jun; 95(6): 2536-2559.

Finkel W, Greenland S, et al. Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men. PLOS ONE. 2014 Jan; DOI: 10.1371.

Brawer MK. Testosterone replacement in men with andropause: an overview. Rev Urol. 2004; 6(Suppl 6): S9-S15.

O’Connor A. New concern about testosterone and heart risks. NYT, Jan 29, 2014.

La Puma J. Don’t ask your doctor about low T. NYT, Feb 3, 2014.

Male menopause: testosterone therapy marketing frenzy draws skepticism. From voxxi.com, Sep 9, 2012.