Factors contributing to gender differences in serum retinol and alpha-tocopherol in infertile couples.

Oxidative stress is detrimental to fertility potential. Retinol and alpha-tocopherol are natural antioxidants that inhibit lipid peroxidation and protect against cell damage induced by oxidative stress. This study evaluated whether gender-related differences in antioxidant status exist among couples with infertility and, if so, to evaluate relevant factors that may contribute to such differences. Retinol and alpha-tocopherol in the sera of 40 couples and in the semen of 40 men were measured using high performance liquid chromatography. Serum retinol and alpha-tocopherol in women were significantly higher than in men (both P < 0.001). There was an inverse relationship between body mass index and serum retinol and alpha-tocopherol in both men and women. Heavy smokers (>or=20 cigarettes/day), compared with nonsmokers, had lower serum concentrations of retinol and alpha-tocopherol. Serum concentrations of retinol and alpha-tocopherol in men with normal sperm parameters were significantly higher than in those with oligozoospermia and asthenozoospermia (both P < 0.001). Lower serum retinol and alpha-tocopherol in men compared with their female partners could be related to their older age, higher body mass index and smoking habits. Low concentrations of these natural antioxidants were associated with abnormal semen parameters in men and anovulation in women.

Significance of simultaneous determination of serum and seminal plasma alpha-tocopherol and retinol in infertile men by high-performance liquid chromatography.

High-performance liquid chromatography was used for the simultaneous determination of alpha-tocopherol and retinol in serum and semen of 40 subfertile men. The serum levels of the two vitamins were significantly higher in serum than in semen (3- to 10-fold) (P < 0.001). The mean alpha-tocopherol levels were higher in the serum and semen of men with normal sperm parameters (20 +/- 5 and 5 +/- 4 mumol L-1) than those with oligozoospermia (10 +/- 4 and 3 +/- 2 mumol L-1), azoospermia (8 +/- 3 and 3 +/- 1 mumol L-1) and asthenozoospermia (9 +/- 6 and 3 +/- 2 mumol L-1) (P < 0.002). Mean retinol levels in serum were similar in men with normal sperm parameters (2.4 +/- 2 mumol L-1) as in those with defective sperm parameters such as oligozoospermia (2.5 +/- 2 mumol L-) and asthenozoospermia (2.1 +/- 1.0 mumol L-) (P = 0.15), but significantly lower in men with azoospermia (1.3 +/- 0.3 mumol L-1) (P < 0.05). The alpha-tocopherol:retinol ratio was significantly higher in semen than in serum of men with normal sperm parameters (11.5) and those with asthenozoospermia (10.3) compared with ratios in those with oligozoospermia (8.3) and azoospermia (6.3). This may be related to reduced antioxidant activity in sperm dysfunction as a result of lipid peroxidation, from increased generation of reactive oxygen species.