Low Testosterone In Men
For overall wellbeing, it is important to have your blood testosterone levels in the normal range and ideally at least in the middle of the normal range.
Testosterone helps to maintain:
- a strong skeleton
- healthy muscles
- healthy brain and nerve function
- healthy cardiovascular function
- a healthy sex drive
- a positive mental and emotional state
As we age, testosterone levels usually reduce, and there is a relatively constant decline in blood testosterone, at a rate of 1% to 2% per year.
In males, the sex hormone testosterone is produced mostly in the testicles.
Most of the testosterone circulating in the bloodstream is bound to a protein called sex hormone-binding globulin (SHBG) and a small amount of testosterone exists as free testosterone. With advancing years, serum-free testosterone decreases to a greater extent than total testosterone because SHGB concentrations are higher in older men than younger men.
Testosterone not only interacts with receptors in end organs such as the bones, brain, muscles, testicles and prostate gland, but through its conversion to estrogen (oestradiol), it can exert female hormone effects. If the liver is fatty or sluggish it will not break down the estrogen and breast enlargement (man boobs) can develop and fat can start to accumulate around the buttocks and thighs.
Signs of testosterone deficiency
- decreased muscle mass and strength (even though you work out at the gym)
- low bone density – osteopenia or osteoporosis
- abdominal obesity
- difficulty losing weight
- sexual problems (erectile dysfunction (ED), loss of morning erections and low libido)
- loss of confidence
- loss of drive to achieve things
- aches and pains (fibromyalgia)
Risk factors for testosterone deficiency
- type 2 diabetes
- prediabetes (insulin resistance)
- fatty liver
- being overweight
- long term users of opioid drugs
- very low cholesterol levels
- some prescription medications (eg. Tegretol, high dose statins, etc) – check with your doctor
- moderate to heavy alcohol intake
Testosterone and fat and lean muscle mass
Obesity is associated with reduced free testosterone and this low testosterone promotes the accumulation of more fat tissue. Low testosterone also causes reduced muscle formation. Testosterone is required for the maintenance of lean muscle mass and muscle strength.
Obese men with very low testosterone levels lose both fat and lean muscle mass during dieting.
If testosterone treatment is given to normalize testosterone levels in these obese men when they are trying to lose weight with diet, studies have shown the testosterone decreases total fat mass and adipose tissue while preserving total lean body mass (muscle). Indeed, testosterone treatment caused a shift to almost exclusive fat mass loss in these patients.
Risks of low testosterone
Low testosterone is now considered a risk factor for cardiovascular disease including heart attacks (myocardial infarction) atherosclerosis and coronary artery disease. Studies show that the risk of stroke is around two times greater for men with low testosterone.
Low testosterone is also associated with an unfavorable metabolic profile, including higher body mass index, greater waist circumference, the presence of diabetes mellitus and high blood pressure.
Low levels of testosterone and oestradiol are associated with increased bone loss and risk of bone fractures in older men. In men and women, some testosterone is converted in to oestrogen in the fat tissue. Testosterone has been shown to decrease bone loss and increase bone mineral density and may interact with vitamin D. This is important to help those with osteopenia and osteoporosis
Testosterone is a steroid hormone that has powerful effects on the brain. Testosterone levels affect mood, cognition, mental energy and wellbeing. Studies show that testosterone treatment improves symptoms of depression in men independent of their initial testosterone level and age.
The American Association for Clinical Endocrinologists, the American College of Endocrinology and the British Society for Sexual Medicine recommend testosterone measurement in all men with type 2 diabetes, a total body mass index >30 kg/m2 or a waist circumference >102 cm.
Testosterone can be administered in the form of patches, gels, creams, lozenges, capsules or injections.
Testosterone is a hormone with many beneficial actions in the body. Testosterone at normal physiologic levels, supports many body systems, and any deviation from these normal levels can manifest in a wide range of health issues.
Measuring your testosterone
Serum testosterone level peaks at about the age of 20 years and gradually declines thereafter.
- Men aged 21–35 years: the reference range for total testosterone measured using mass spectrometry is 10.4–30.1 nmol/L.
- In healthy men aged 70–89 years: the reference range using mass spectrometry is 6.4–25.7 nmol/L.
American consensus statements say a testosterone level above 11.1 nmol/L is normal, below 6.9 nmol/L indicates low testicle function, and 6.9–11.1 nmol/L is equivocal. In Europe those figures are respectively 12, 8 and 8–12 nmol/L.
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