LOH (late-onset hypogonadism) syndrome.

Testosterone deficiency has recently drawn wide attention due to the high prevalence of hypo-gonadal symptoms in the aging male population. A number of studies have reported the beneficial effects of testosterone replacement therapy for men with late-onset hypogonadism (LOH) syndrome. Based on the study evaluating the age distribution of serum testosterone concentration, serum free testosterone less than 8.5 pg/mL is considered as a good indica- tion for testosterone replacement therapy among the Japanese population. However, at present, testosterone enanthate is the only drug that is covered by health insurance in Japan. Further studies are needed to establish more suitable treatment in men with LOH syndrome among Japanese population.