Association Between Urinary Parabens and Sperm Quality in Nigerian Men: A Case–Control Study

Friday Ebhodaghe Okonofua,1– 3 Lorretta Favour Chizomam Ntoimo,1,3,4 Emmanuel Unuabonah,5,6 Titus Alfred Makudali Msagati,7 Makuachukwu Chioma Ekwo,3 Oladiran Frederick Ayodeji,8 Michael Emefiele Aziken,2 Kenneth Toby Maduako,1,2 Vivian Ifunanya Onoh,1 Akhere Omonkhua,1,9 Victor Ohenhen,10 Celestina Oluwaseun Olafusi,11 Moses O Alfred5,6 1Centre of Excellence in Reproductive Health Innovation (CERHI), University of Benin, Benin, Edo State, Nigeria; 2Department of Obstetrics and Gynaecology, University of Benin Teaching Hospital, University of Benin, Benin, Edo State, Nigeria; 3Women’s Health and Action Research Centre (WHARC), Benin City, Edo State, Nigeria; 4Department of Demography and Social Statistics, Federal University Oye-Ekiti, Oye-Ekiti, Ekiti State, Nigeria; 5Department of Chemical Sciences, Redeemer University, Ede, Osun State, Nigeria; 6African Centre of Excellence for Water and Environmental Research (ACEWATER), Redeemer’s University, Ede, Osun State, Nigeria; 7Institute for Nanotechnology and Water Sustainability, College of Science, Engineering & Technology, University of South Africa, Pretoria, South Africa; 8Department of Obstetrics and Gynaecology, University of Medical Sciences, Ilaje, Ondo State, Nigeria; 9Department of Medical Biochemistry, School of Basic Medical Sciences, University of Benin, Benin, Edo State, Nigeria; 10Department of Obstetrics and Gynaecology, Central Hospital, Benin, Edo State, Nigeria; 11Department of Biochemistry, Faculty of Basic Medical Sciences, University of Medical Sciences, Ilaje, Ondo, NigeriaCorrespondence: Friday Ebhodaghe Okonofua, Women’s Health and Action Research Centre Km 11 Benin Lagos Expressway, Igue-Iheya, Benin City, Edo State, Nigeria, Email feokonofua@yahoo.co.uk; friday.okonofua@cerhi.uniben.eduBackground: Parabens, which are chemicals used as preservatives in cosmetic and pharmaceutical products, have been reported to be associated with low sperm quality in animal and human models. Despite the high exposure of men to paraben-containing products in Nigeria, there are no known studies that investigate the association of parabens with sperm quality in the country.Objective: To determine the association of urinary levels of metabolites of parabens with sperm count and quality.Design/Setting: A multicenter case–control study among fertile and infertile men in five hospitals in southern Nigeria. A total of 136 men diagnosed with male infertility (cases) were compared with 154 controls with normal fertility. Urinary levels of parabens (ethyl-paraben, methylparaben, propylparaben, and butylparaben) were measured using liquid chromatography mass spectrometry, while semen analysis and hormone assays were carried out using World Health Organization standards and radioimmunoassay, respectively. Data were analyzed with non-parametric statistics and non-parametric linear regression.Results: The results showed high levels of parabens in both cases and controls. However, there was no statistically significant difference in urinary levels of ethyl-paraben, methylparaben, propylparaben, and butylparaben between cases and controls. In contrast, propylparaben had a decreasing association with total motility in both groups, but the effect was only statistically significant in the case of male infertility. The results of the regression analysis showed that a unit increase in propylparaben significantly decreased total motility in the cases (infertile men). Similarly, a unit increase in propylparaben decreased morphology significantly in the unadjusted model for infertile men. Only serum testosterone showed an insignificant correlation with urinary parabens.Conclusion: We conclude that urinary parabens are associated with features of poor sperm quality – motility, morphology, and volume. Measures to reduce exposure of men to agents containing parabens in Nigeria may reduce the prevalence of male infertility in the country.Keywords: male infertility, Nigeria, parabens, LCMS, case–control study, spermatozoa