Objective: To investigate the relationship between the level of the stress biomarker salivary alpha amylase (SAA) and semen quality in infertile young men.
Methods: Totally, 313 infertile and 96 normal healthy men, aged 20－40 years old, were enrolled in this study. The SAA levels and semen parameters of the subjects were measured and compared between the two groups.
Results: Compared with the normal healthy controls, the young infertility patients showed a significantly higher SAA level (［141.04 ± 44.13］ vs ［151.48 ± 38.42］ μmol/L, P < 0.05) and percentage of immotile sperm (IMS) (［39.98 ± 14.53］% vs ［64.48 ± 26.32］%, P < 0.05), but lower sperm concentration (［44.23 ± 21.63］ vs ［32.42 ± 23.07］ ×10⁶/ml, P < 0.05) and percentage of progressively motile sperm (PMS) (［52.13 ± 15.42］% vs ［27.91 ± 21.22］%, P < 0.05). Sperm concentration (［26.33 ± 31.83］ vs ［35.28 ± 27.70］ ×10⁶/ml, P < 0.05) and the percentage of PMS were remarkably lower in the infertile men with a high than in those with a low SAA level (［19.85 ± 21.55］% vs ［31.70 ± 20.02］%, P < 0.05), while the percentage of IMS was higher in the former than in the latter group (［74.19 ± 26.84］% vs ［59.92 ± 24.85］%, P < 0.05). The SAA level in the young infertility patients was correlated positively with the percentage of IMS (r = 0.170, P < 0.01), but negatively with sperm concentration (r = －0.227, P < 0.01) and the percentage of PMS (r = －0.468, P < 0.01).
Conclusions: The stress biomarker salivary alpha amylase level in infertile young men is negatively correlated with semen quality, and therefore semen parameters can be improved by reducing the stress level.
Keywords: semen quality; stress; male infertility.