Calling all men, and those that care about them. Have you thought how testosterone affects the skeleton? At what age are bones their strongest? Why do some older men break a hip and not others?
Testosterone is an important hormone for both bone growth and development, in men. However the amount of men’s testosterone starts to slowly decline after about age 30. It is estimated that 10% of men over the age of 50 experience symptoms of low testosterone and 19% of men over 60 have low testosterone levels.
Do not rush out to get testosterone therapy! Proper clinical evaluation and evidenced-based knowledge of the risks, benefits and side effects of testosterone therapy is important. Commitment to the necessary follow-up treatment with the desired adjustments to your lifestyle are also key to the safe return to normal range testosterone levels. Read further…
What is testosterone?
Androgens are the male hormones secreted by the gonads or testicles and, to a small degree, the adrenal glands located on top of both kidneys. Testosterone, the main androgen, is the male hormone responsible for sperm cell development and secondary sexual features, such as muscle mass and strength, deep voice, and sex drive or libido. Testosterone affects many of the body’s organs and systems such as brain, heart, and skeleton.
Testosterone and age
The testosterone level in men peaks at about age 20 then levels off. Few men are aware of their peak testosterone level as it is seldom measured at that age. Around age 30 testosterone starts to slowly decline at a rate of about 1% per year. The decline in testosterone with age remains gradual, unlike the rapid decline of estrogen experienced by women at menopause. Moreover, a significant decline in testosterone levels is neither universal nor is it experienced by all aging males.
Testosterone levels vary throughout the day and are affected by age, body mass index, nutrition, alcohol consumption, certain medications and diseases. However, it is not until a testosterone level is below 300ng/dL that it is considered hypogonadal or low.
Hypogonadism (low testosterone) in men
Hypogonadism is a condition in which the body does not produce enough sex hormones. In men, too little or low testosterone may be an age-related condition, some times know as ADAM (androgen deficiency in the aging male) or the result of damage of the pituitary, certain prostate cancer therapies, removal of testicles, or several other causes.
Age-related hypogonadism in men can reach a point where the level of testosterone is so low it may cause medical symptoms that require attention, such as depression or weak bones.
The symptoms can be vague and vary significantly from one man to another making it difficult to diagnose. Some will describe the feeling, saying “I used to be a jock, now I’m a couch potato.” According the to American Urology Association 2018 guidelines “… there are a large percentage of men in need of testosterone therapy who fail to receive it due to clinician’s concerns, mainly surrounding prostate cancer development and cardiovascular events, although current evidence fails to definitely support these concerns.” People should be informed of the absence of evidence linking testosterone therapy to the development of prostate cancer or whether testosterone therapy increases or decreases the risk of cardiovascular events. (i) (ii)
Clinical Symptoms
The symptoms of low or too little testosterone may be a decrease in bone density, muscle mass and strength, libido, blood cell formation, cognitive function, and general well being. You may also experience an increase in obesity, erectile dysfunction, and depressed mood. Even more devastating, the consequence of not managing low testosterone could impact bone remodeling over several years which may result in a spine or hip fracture.
Your healthcare professional (HCP) may suspect these symptoms are caused by something other than low testosterone, such as depression, saying “You are getting older, what do you expect?” or “At your age, you will have more aches and pains” or “You can’t expect to do what you did at age 30.”
The ADAM (androgen deficiency in the aging male) questionnaire, developed by Dr J Morley is non-invasive clinical screening tool that provides questions to help identify hypogonadal males over age 40. It is designed so you can ask yourself, if over time do you have a decrease in your desire for sex and are you experiencing erections less strong, then speak with your HCP. As well, ask do you have a decrease in energy, strength and/or endurance, height, enjoyment in life, ability to play a sport, performance at work, or are you falling asleep after dinner? Understandably, we all have days we “feel old”, and some of these feelings and changes may be chalked up to aging. However, if you answer yes to any three questions including those of sexual desire and erections, keep a record of dates, times, signs and symptoms. If they persist discuss them with your HCP.
The diagnosis of too little testosterone or androgen deficiency in an aging male can only be made if there are persistent clinical symptoms and consistently low circulating testosterone levels.
Laboratory tests
As a man ages, sex hormone binding globulin (SHBG), a protein in the blood that binds to circulating testosterone, increases. This results in less testosterone available to reach tissues such as brain, heart, and bones. The testosterone that remains available to reach the tissues is called bioavailable testosterone.
Usually the initial laboratory blood test is a total testosterone level, although the more expensive bioavailable testosterone test may more accurately show if there is a testosterone deficiency.
Confirmation of testosterone deficiency should be made on two or more days of morning blood samples. Laboratory work done should be done at the same laboratory, as assays may vary. Read the laboratory instructions carefully as they often want fasting blood work, taken before 10:00 AM that morning.
Testosterone Therapy (TT)
The principal goal of TT in men with low testosterone is to restore testosterone concentrations to the mid-normal range. When considered on an individual bases, all other causes ruled out, and the clinical evaluation and laboratory work show hypogonadism, TT may be appropriate. TT should not be confused with treatments used for erectile dysfunction (ED) – for example taking Viagra, Cialis or Levitra, or used interchangeably.
Follow-up
TT must be closely monitored with blood tests, digital rectal exam and possible PSA test for response to therapy and side effects. If over dosed your risk may include low sperm count, prostate enlargement, acne, headaches, heart or liver problems, insomnia, high blood pressure, aggressive behavior or mood swings.
If testosterone is not adequately restored your risks include low bone density, among others. Not identifying bone loss for several years could result in a devastating, life-altering, spine or hip fracture!
To maintain an optimal testosterone level requires a balanced lifestyle with regular exercise, a proper, balanced, nutritious diet and good sleep. Minimize alcohol consumption and stress, maximize laughter and happiness, and consult a pharmacist about medicines that may impact your testosterone levels.
Bone Health
Although not a treatment for osteoporosis, TT may be recommended for men with hypogonadism to prevent further bone loss and osteoporosis. Be sure to talk to your HCP about the appropriate calcium, vitamin D, and exercises necessary to maintaining strong bones after you have reached your peak bone density level which occurs usually by age 25.
Additional Resources
Testosterone is not enough by itself to restore bone health. To provide accurate and easy to follow information about secondary causes of bone loss, osteoporosis, fracture prevention through diet and exercise, disease management and medications, I co-wrote Bone Health Basics: Tips for Preventing and Managing Osteoporosis with leading Canadian rheumatologist Dr. John Wade. If you are a healthcare professional and would like more detail, we also have The Osteoporosis Book: Bone Health, 4th Edition, which I wrote with pharmacist Dr. Alan Low and John. You can find these books here.
(i) Mulhall JP, Trost LW, Brannigan RE et al: Evaluation and management of testosterone deficiency: AUA guideline. J Urol 2018; 200: 423
(ii) S Bhasin, JP Brito, GR Cunningham et al (2018). Testosterone Therapy in Men with Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab, May 2018, 103(5):1715–1744, https://doi.org/10.1210/jc.2018-00229;
(iii) A Yassin, K AlRumaihi, R Alzubaidi, et al (2019) Testosterone, testosterone therapy and prostate cancer, The Aging Male, 22:4, 219-227, DOI: 10.1080/13685538.2018.1524456