Testosterone deficiency in men: systematic review and standard operating procedures for diagnosis and treatment.

Introduction: Testosterone (T) deficiency (TD) may significantly affect sexual function and multiple organ systems.

Aim: To provide recommendations and Standard Operating Procedures (SOPs) based on best evidence for diagnosis and treatment of TD in men.

Methods: Medical literature was reviewed by the Endocrine subcommittee of the ISSM Standards Committee, followed by extensive internal discussion over two years, then public presentation and discussion with other experts.

Main Outcome Measure: Recommendations and SOPs based on grading of evidence-based medical literature and interactive discussion.

Results: TD is the association of a low serum T with consistent symptoms or signs. T level tends to decline with age. T modulates sexual motivation and erection. It also plays a broader role in men's health. Recent studies have established associations between low T, male sexual dysfunctions and metabolic risk factors. Though association does not mean causation, low T is associated with reduced longevity, risk of fatal cardiovascular events, obesity, sarcopenia, mobility limitations, osteoporosis, frailty, cognitive impairment, depression, Sleep Apnea Syndrome, and other chronic diseases. The paper proposes a standardized process for diagnosis and treatment of TD, and updates the knowledge on T therapy (Tth) and prostate and cardiovascular safety. There is no compelling evidence that Tth causes prostate cancer or its progression in men without severe TD. Polycythemia is presently the only cardiovascular-related adverse-event significantly associated with Tth. But follow-up of controlled T trials is limited to 3 years.

Conclusions: Men with sexual dysfunctions, and/or with visceral obesity and metabolic diseases should be screened for TD and treated. Young men with TD should also be treated. Benefits and risks of Tth should be carefully assessed in older men. Prospective, long-term, placebo-controlled, interventional studies are required before screening for TD in more conditions, including cardiovascular diseases, and considering correction of TD as preventive medicine.