Relationship between serum zinc concentration and semen quality in newly-wed men.

OBJECTIVES To clarify factors associated with semen quality and confirm whether there is an association between semen quality and serum zinc concentration. METHODS A semen test was performed on 217 men just after or just before marriage. Variables assessed in the study were: age; symptomatic scores, including sexual function evaluated using several specific questionnaires; endocrinological profiles, especially follicle-stimulating hormone; and serum zinc concentrations. Based on World Health Organization criteria for assessing sperm quality, semen volume ≥1.5 mL, sperm concentration ≥15 million/mL, or sperm motility rate ≥40%, the men were grouped according to whether they had values below or above these criteria. The two groups were compared with regard to the study variables, and correlation between serum zinc concentration and semen quality was evaluated. Independent predictors for inclusion in the group with values below the criteria were investigated further. RESULTS Of the 217 men included in the study, 45 (20.7%) were categorized as having values below the World Health Organization criteria. The men in this group were significantly older and had significantly worse sexual function, significantly higher follicle-stimulating hormone levels, and significantly lower serum zinc concentrations, than those in the group with values above the criteria. There was no significant correlation between serum zinc concentration and semen quality. However, the independent predictors for having values below the criteria in binomial logistic regression analysis were follicle-stimulating hormone and serum zinc concentration. CONCLUSION We suggest that semen analysis may be considered in men with a low level of serum zinc and high level of follicle-stimulating hormone when developing a life plan for fertilization.