Male Testosterone Deficiency Is a Health Hazard
According to a number of modern studies, testosterone deficiency in men can be deadly. Testosterone deficiency is associated with a number of health problems and diseases. This includes insulin resistance, obesity, abnormal lipids, high blood pressure, osteoporosis, muscle weakness and frailty, cognitive impairment (poor memory and focus), fatigue, Type 2 diabetes, and sexual dysfunction (low libido and erectile dysfunction).
Research has shown that the risk of death is definitely higher in men with testosterone deficiency. A 2011 review and analysis of 12 studies found that low testosterone levels were associated with an increased risk of all-cause and cardiovascular mortality.And a study done on Californian men aged 51-91 found that men with low testosterone levels (defined by this study as less than 241 ng/dL) were 40% more likely to die than those with higher testosterone levels. Other variables were taken into account such as lipid levels, age, and other factors. The same study found low testosterone levels were associated with death from respiratory and cardiovascular disease.
Low testosterone has been shown in numerous studies to be a significant risk factor for cardiovascular risk factors and events. It has a direct effect because of its effect on blood clotting, blood vessel health which includes artery dilation and inflammation. Testosterone has an indirect effect on cardiovascular risk because when deficient it makes one more susceptible to central obesity (abdominal fat around the abdomen), elevated lipids, and insulin resistance.
Researchers analyzed data of almost 20,000 men who received testosterone therapy for 5 years (2009-2014). They found the “risk for a heart attack was 7-fold lower and the risk for stroke 9 times lower compared with samples from the general population. Further, there was no evidence of worsening of preexisting MI or stroke in patients treated with testosterone. 
The question of whether testosterone replacement in men causes prostate cancer? This is based on very old observations and has been refuted by many large, updated studies. Reported at the 2015 American Urological Association Annual meeting, researchers used a meta-analysis of a variety of studies including 5091 patients with prostate cancer and 11,930 control subjects as well as 24 randomized placebo controlled trials of testosterone therapy that reported data on PSA and prostate cancer patients. Their findings found that testosterone replacement does not cause prostate cancer or increase PSA levels in men. Interestingly, one study published in the journal Prostate found that more aggressive and advanced prostate cancers seemed to be associated with lower testosterone levels.
In summary, men over the age of 40 should have their testosterone levels checked yearly. The evidence suggests that a low testosterone level is a serious health risk to men and greatly hinder quality of life on many different levels. Many men seek my care at the Stengler Center for Integrative Medicine in regards to their testosterone replacement therapy.
 Araujo, A.B., Dixon, J.M., Suarez, E.A. et al. (2011) Endogenous testosterone and mortality in men: a systematic review and meta-analysis. Journal of Clinical Endocrinology and Metabolism, 96, 3007–3019.
 Laughlin GA, Barrett-Connor E, Bergstrom J. Low serum testosterone and mortality in older men. J Clin Endocrinol Metab. 2008;93:68-75
 American Association of Clinical Endocrinologists (AACE) 23rd Annual Scientific and Clinical Congress. Presented May 16, 2014.
 Schatzl G, Madersbacher S, Thurridl T, et al. High-grade prostate cancer is associated with low serum testosterone levels. Prostate. 2001;47:52-58