ABSTRACT
Research question: To assess the levels of seminal biomarkers fructose, zinc and citrate and their correlations to semen parameters in infertile men. Design: 200 infertile male participants undergoing fertility assessment at Singapore General Hospital (SGH), Singapore were recruited prospectively, from June 2020 to August 2021. Their semen samples were assessed for seminal parameters, biomarker levels of fructose, citrate and zinc, leukocyte concentrations and aerobic cultures. They were also assessed for their smoking habits. Results: Sperm concentrations were negatively correlated to seminal fructose levels, r = -0.262, P < 0.001. Progressive motility were positively correlated to seminal citrate levels, r = 0.181, P = 0.014. Sperm morphology and total motile sperm count (TMSC) were positively correlated to seminal zinc and citrate levels, P < 0.05. Zinc and citrate levels were significantly reduced in teratozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia groups compared to normozoospermia, P < 0.05. The presence of infection was associated with elevated leukocyte concentrations, lower sperm concentration (12.5 vs 55.8 million/mL, P = 0.024) and fructose levels (35.5 vs 49.2 µmol/ejaculate). Heavy smokers compared to light smokers, had lower sperm concentrations (35.3 vs 49.4 million/mL), TMSC (30.9 vs 47.5 million) and zinc levels (4.9 vs 6.7 µmol/ejaculate) and significantly lower citrate levels (52.6 vs 79.2 µmol/ejaculate, P = 0.029). Conclusions: Higher zinc and citrate levels correlated with better progressive motility, sperm morphology and TMSC. Smoking negatively impacted zinc and citrate levels, thereby affecting sperm quality. In conclusion, the inclusion of biomarkers in basic male work-up assessment would assist in identifying common deficiencies and aid in adequate replacement therapy.
ABSTRACT
The objective of this retrospective study was to distinguish between fertile and subfertile men based on their semen parameters and hamster egg penetration test (HEPT) outcome. This study involved 110 subfertile men recruited from an infertility clinic and 48 fertile men attending an antenatal clinic in Singapore. The men were required to donate a semen specimen for semen analysis and HEPT assay. The results indicated that the subfertile group had significantly lower normal sperm morphology according to the Tygerberg strict criteria, and lower progressive motility (P < .05). Semen volume, density, HEPT decondensation rate, and sperm penetration index were not significantly different between the 2 groups. Receiver operating characteristic curve analysis indicated that sperm morphology had the highest predictive power of 65.7% with a threshold value of 7%, and progressive motility had a predictive power of 61.8% with a threshold value of 50%. Using the tenth percentile of the fertile population as the cutoff, lower adjusted thresholds of 3% for sperm morphology and 28% for progressive motility were obtained, giving higher positive predictive values of 81.8% and 84.4%, respectively. This study shows that these new cutoff values can be used to screen the general population to identify subfertile men. In contrast, the HEPT proved to be an insensitive and unreliable assay in identifying subfertile males. To our knowledge the comparison of HEPT and semen parameters between subfertile and fertile men has not been previously reported in an Asian population.
