Dynamics of estradiol and testosterone and seminal fluid indexes in smokers and nonsmokers.

The serum levels of estradiol (E2) and testosterone (T), the metabolic clearance rates of estradiol (MCRE2) and testosterone (MCRT), and the production rates of estradiol and testosterone (PRE2) and (PRT) were examined in 22 male smokers and 21 male nonsmokers. Seminal fluid indexes (sperm count, % motility, grade of motility, and % of sperm with abnormal morphology) were also assessed. The mean E2 level and the mean PRE2 were significantly greater in smokers than in nonsmokers (P less than 0.001 and P less than 0.01, respectively); however, the means of MCRE2, MCRT, PRT, and T did not differ significantly in smokers compared to nonsmokers. No significant product-moment correlations were found between the various hormonal measures and the seminal fluid indexes in the overall sample. However, the smokers with sperm counts below the median sperm count of the sample had significantly higher mean levels of E2 and PRE2 than did the smokers with sperm counts above that median. Mechanisms that might mediate the greater PRE2 of smokers and a negative relationship between estradiol and sperm count are discussed.