Effects of testosterone replacement therapy in hypogonadal men with type 2 diabetes. Systematic review

Although the precise prevalence of adult onset hypogonadism is not known, current data suggests that around 13.8% of males have low testosterone (T) levels, while 5.6% of men have a symptomatic androgen deficiency. Impaired testicular function impair quality of life (QoL) and affects many systems. Symptoms vary between changes in sexual health and mood to alteration in body composition and feminisation (gynecomastia, infertility, a decrease in muscle mass and body hair, underdevelopment of sex organs). Manifestation differs greatly and depends on the cause, severity, development speed, age of the patient and other factors. It has been shown that that men with T2D diabetes have lower testosterone levels, while hypogonadal males are at higher risk of developing T2D. A correlation has been observed between androgen deficiency, sex hormone binding globulin (SHBG) levels and increased mortality in patients with T2D, independently to most known T2D risk factors. The causes for decreased T levels due to T2D have not been fully elucidated, however, it is known that androgens affect metabolic target tissues (adipose, musculoskeletal), play a significant role in glucose and lipid regulation, thus are crucial in the etiopathogenesis and progression of cardiovascular and metabolic diseases, including diabetes. No current studies have compared the differences between the effect of TRT on hypogonadal males and males with T2D. This is an significant element to consider when treating diabetic males, seeing as the developmental factors and phenotype of hypogonadism differs from those with “classical” hypogonadism