A study on spermatogenesis in elderly men : Changes in seminal volume, sperm density, motility, seminal transferrin, fructose and zinc

During the past decade a number of studies have dealt with endocrine testicular function and sexual behavior in aged males. However, information on seminal parameters in senescence has remained very scanty. This prompted us to initiate a study on seminal parameters in aged males as an indicator of spermatogenesis. A total of 458 subjects, aged 20 years or more who had children produced semen sample. Subsequently seminal volume, sperm density and motility were assessed. Seminal transferrin levels also were determined by radioimmunoassay as an indicator of Sertoli cell function. Seminal fructose and zinc were determined as indicators of accessory genital gland function. Seminal volume was significantly less in the aged male group (40 yrs. or more) than in normal younger males (20-29 yrs.). Sperm density was not changed with aging. Concerning total sperm counts, normal younger males had 214 million cells per ejaculate. Subjects aged 50 years or older had significantly lower total sperm counts (50 yrs.: 161 million cells, 60 yrs.: 94 million, 70 yrs.: 27 milliom) compared to those of normal younger males. These findings suggest that spermatogenic impairment occurs with aging. Seminal fructose content of the semen in normal younger males was also significantly elevated compared to aged males (60 yrs. or more). The mean zinc content in the semen in normal younger males was significantly elevated compared to aged males (60 yrs. or more). These findings showed that the functions of prostate and seminal vesicles were impaired in elderly males and subsequently resulted in a decrease of seminal volume. Seminal transferrin volume was decreased with aging and correlated significantly (r=0.609) with total sperm counts. This finding suggested that Sertoli cell function was reduced in elderly males. In conclusion, the decrease of seminal volume resulting from accessory genital gland dysfunction and Sertoli cell dysfunction seems to be one of the causes of spermatogenic failure in elderly males