Testosterone is a sex hormone that has a significant effect on the body. In both men and women, testosterone helps grow and maintain reproductive tissue and bone mass. In men, testosterone regulates libido, fat distribution, strength, and muscle mass. It also supports the production of red blood cells and sperm. When a man hits puberty, testosterone is the hormone that becomes the catalyst to body hair growth, pubic hair growth, the deepening of his voice, and the development of the penis and testes. Without testosterone, men have problems regulating mood and face a host of health problems.
As men age, a gradual drop in body testosterone levels occurs – at about 2% every year.
Less testosterone is produced by the testes and the pituitary gland sends fewer signals to the testes to make testosterone. Over 30% of men over age 45 experience below normal levels of testosterone, which manifests as physical symptoms and can be identified through a blood test.
As one of the main functions of testosterone is to regulate sexual health in men, signs of testosterone deficiency in adult men can appear as impairment in sexual function, including loss of sex drive, difficulty becoming and staying erect, reduced testicle size, reduced sperm count, and infertility. Men with low testosterone can also experience reduced facial and body hair, reduced muscle mass, increased breast size, difficulty regulating mood, and osteoporosis. Women can also be affected by symptoms of testosterone deficiency. Like men, they may experience difficulty concentrating, low libido, depression, and reduced bone strength.
Low testosterone levels can be caused by certain conditions and diseases, including damage to the testes, damage to the pituitary and hypothalamus glands, infections, autoimmune conditions, and genetic disease. Sustained low testosterone levels pose many risks – osteoporosis is one of the main concerns when a person is diagnosed with lowered testosterone levels. Testosterone deficiency is also linked to diabetes – men with diabetes are statistically more likely to have low testosterone, and men with low testosterone are more likely to eventually develop diabetes. Testosterone affects the body’s ability to respond to insulin and consume blood sugar, and men with low testosterone have higher chances of insulin resistance which affects the amount of insulin they need to maintain blood sugar levels.
Obesity and low testosterone are also linked. Similar to diabetes, men with reduced testosterone levels are likely to become obese, and obese men are likely to have reduced testosterone levels. Men with testosterone deficiency are also at risk of developing metabolic syndrome, a condition that increases the risk of heart attacks and strokes, and manifests in the form of abnormal cholesterol levels, waistline obesity, high blood sugar, and high blood pressure.
Testosterone deficiency is linked to insulin resistance, diabetes, and obesity – all of these increase cardiovascular risk. Men with low testosterone levels and diabetes are also at risk of arterial hardening, which can cause erectile dysfunction in older men. Lowered testosterone levels can also cause depression in men, even after adjusting risk variables like general health, age, and obesity. Identifying risks of testosterone deficiency can be difficult, as many conditions can cause or be caused by low testosterone levels, including side effects of medication, thyroid problems, and obstructive sleep apnea.
Increased exercise, a healthy diet and weight loss can positively affect testosterone levels as well as alleviate any symptoms. Testosterone replacement therapy can be administered through injection of gels and liquids, implanted testosterone pellets, or topical testosterone in the form of gels, creams, and liquids.