Seminal Biomarkers and Oxidative Stress Parameters in Infertile Cigarette Smokers: A Study from Port Harcourt, Nigeria
Laurretta Lekpoa Nwisah *
Department of Clinical Chemistry, Faculty of Medical Laboratory Science, River State University, Port Harcourt, Nigeria.
Adline Erinma Ben-Chioma
Department of Clinical Chemistry, Faculty of Medical Laboratory Science, River State University, Port Harcourt, Nigeria.
Edna Ogechi Nwachuku
Department of Clinical Chemistry, Faculty of Medical Laboratory Science, River State University, Port Harcourt, Nigeria.
Donatus Onukwufor Onwuli
Department of Clinical Chemistry, Faculty of Medical Laboratory Science, River State University, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Cigarette smoking is a common lifestyle exposure among infertile men; however, its effects on seminal antioxidant status in Nigerian populations are not well documented.
Aim: To compare seminal biomarkers (zinc and fructose), inflammatory cytokines [interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)], antioxidant biomarkers [superoxide dismutase (SOD) and reduced glutathione (GSH)], and the oxidative DNA-damage marker 8-hydroxy-2′-deoxyguanosine (8-OHdG) between cigarette-smoking and non-smoking infertile men attending the Rivers State University Teaching Hospital (RSUTH), Port Harcourt.
Methods: This cross-sectional analysis included 84 men with abnormal semen parameters recruited from the fertility clinic of RSUTH. Participants were classified by current cigarette-smoking status as smokers (n = 27) or non-smokers (n = 57). Seminal plasma zinc, fructose, IL-6, TNF-α, SOD, GSH, and 8-OHdG were quantified by competitive enzyme-linked immunosorbent assay (ELISA). Data were analysed using an independent-samples t-test in the Statistical Package for the Social Sciences (SPSS), version 27, with statistical significance set at p ≤ 0.05.
Results: Twenty-seven of the 84 infertile men (32.1%) reported current cigarette smoking. Mean seminal zinc concentration was significantly lower in smokers than in non-smokers (3.52 ± 0.97 vs 4.15 ± 0.67 µmol/L; p = 0.049), representing an approximate 15.2% reduction. SOD activity (12.12 ± 2.45 vs 15.72 ± 2.90 U/mL; p = 0.047) and GSH concentration (1.14 ± 0.30 vs 1.44 ± 0.29 µmol/L; p = 0.023) were also significantly lower in smokers. Fructose, IL-6, TNF-α, and 8-OHdG did not differ significantly by smoking status (p > 0.05).
Conclusion: Among the infertile men studied, cigarette smoking was associated with lower seminal zinc, SOD, and GSH, whereas fructose, IL-6, TNF-α, and 8-OHdG did not differ significantly between smokers and non-smokers. These findings indicate an association between cigarette smoking and reduced seminal antioxidant status in this study population.
Keywords: Cigarette smoking, seminal biomarkers, inflammatory cytokines, oxidative stress, male infertility, antioxidant status