The term “low T” has become synonymous with middle-aged men in primetime commercials. But do you know what it really means?

 

“Low T” refers to a hormone called testosterone that is produced by the testicles, and is responsible for the development of male sexual characteristics. However, as a man ages, the amount of testosterone in his body gradually declines. This natural decline starts after age 30 and continues throughout life.

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The Baltimore Longitudinal Study of Aging, one of the longest studies available to evaluate changes over time in testosterone levels, followed 890 healthy, middle-aged males and found that:

• By age 60, 20 percent had low testosterone

• By age 70, 30 percent had low testosterone

• By age 80, 50 percent had low testosterone

 

Role of testosterone

Testosterone is not just important for sexual function, it also is important for maintaining muscle mass, adequate levels of red blood cells, bone growth and an overall sense of well-being. Inadequate production of testosterone, also known in the medical community as “hypogonadism,” can be a cause of erectile dysfunction, and testosterone replacement therapy may improve the problem.

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Additional causes of hypogonadism

• Obesity

• Chronic illness, chronic kidney disease and chronic liver disease

• Alcoholism

• Stress

• Dysfunction of the pituitary gland, which is the “master gland” that sits between the lobes of the brain

• Injury, infection, or loss of testicles

• Certain cancer treatments

• Genetic abnormalities

• Too much iron in the blood (hemochromatosis)

• Hemochromatosis (too much iron in the body)

 

Possible symptoms

There is no one specific symptom, but may include any or all of the following:

• Sexual – decreased frequency of morning erections, decreased frequency of sexual thoughts, erectile dysfunction

• Physical – inability to engage in vigorous activity, difficulty walking >1km, inability to bend or stoop

• Psychological – loss of energy, sadness, fatigue

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Screening for “Low T”

Your doctor may ask a number of questions to screen you first. One of the most common surveys used is the ADAM (Androgen Deficiency in the Aging Male) questionnaire, which contains the following questions:

1. Do you have a decrease in sex drive (libido)?

2. Do you have a lack of energy?

3. Do you have a decrease in strength or endurance?

4. Have you lost height?

5. Do you notice a decrease in enjoyment in activities you otherwise liked?

6. Are you sad and/or grumpy?

7. Are your erections less strong?

8. Have you noticed a decrease in ability to play sports?

9. Are falling asleep after dinner?

10. Has there been a recent deterioration in your work performance?

 

If you answer “yes” to number 1 or 7, or “yes” to more than 3 questions, you may have low testosterone.

 

The most accurate way to detect the condition is to have your doctor measure the amount of testosterone in your blood. Because testosterone levels fluctuate throughout the day, several measurements will need to be taken to detect a deficiency. Doctors prefer, if possible, to test levels early in the morning since this is when testosterone levels are at their highest and more than one test is required for knowing definitely.

The most common treatment for low testosterone is testosterone replacement, in addition to healthy lifestyle changes, which may be negatively affecting levels.

 

Testosterone replacement therapy

Your doctor should discuss the benefits and risks of testosterone replacement therapy.

Benefits of T therapy include:

• Libido, erections and sexual activity

• Energy, mood and vitality

• Bone mineral density

• Muscle strength and function

 

Risks may include:

• Breast enlargement (uncommon)

• Prostate biopsy (due to monitoring)

• Formula related adverse effect

• Obstructive sleep apnea (rare)

 

There are multiple different forms of testosterone replacement therapies–intramuscular injections, skin preparations (either patch or gel), pellets placed under the skin, or a form that is placed between your gum and the side of your mouth (buccal). Your doctor should discuss all the the advantages and disadvantages, but your insurance company may be the ultimate say in which form will be covered by your plan. If you are started on testosterone replacement, your doctor will follow routine labs to achieve the best levels, as well ask you questions on how you are feeling in general.

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References:

Bhasin S, Cunningham GR, Hayes FJ, Matsumoto AM, Snyder PJ, Swedloff RS, Montori VM. Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2010;95:2536-2559.

Bolona ER, Uraga MV, Haddad RM, Tracz MJ. Testosterone use in men with sexual dysfunction: A systematic review and meta-analysis of randomized-;placebo controlled trials. Mayo Clin Proc 2007;82:20-28.

Fernandez-Balsells MM, Murad MH, Lane M, Lampropulos JF. Clinical review; adverse effects of testosterone therapy in adult men: a systematic review and meta-analysis. J Clin endocrinol Metab. 2010; 95 (6):2560-75.

Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman MR. Longitudinal effects of aging on serum total and free testosterone levels in healthy men: Baltimore Longitudinal Study of Aging. J Clin Endocrinol Metab. 2001;86:724-731.

Jain P, Rademaker AW, McVary KT. Testosterone supplementation for erectile dysfunction: results of a meta-analysis. J Urol 2000;164:371-375.

Wu FW, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med 2010;363:123-135.