Association between per- and polyfluoroalkyl substances and sex hormone levels in males based on human studies

Background: Per- and poly-fluoroalkyl substances (PFAS) are ubiquitous chemicals in the environment and our daily lives. Several epidemiological studies have revealed that PFAS exposure is linked to male sex hormone levels; however, the conclusions are inconsistent across studies. Consequently, we performed a meta-analysis to systematically evaluate the association between PFAS exposure and male sex hormones. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards were followed during the meta-analysis. PubMed, Wed of Science, Embase, Cochrane Library, and Ovid databases were used to identify suitable articles before June 2023. The 95% CI and 0 values were calculated to assess the association between male sex hormone levels and PFAS exposure. Heterogeneity among the included studies was tested using inconsistency statistics (I2). Results: The literature search identified 12 published articles that met our search criteria, involving 7506 participants. Our results revealed that perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA) exposures were negatively correlated with testosterone (0 = -0.05; 95% CI: -0.09, -0.02, P = 0.003) and (0 = -0.04; 95% CI: -0.08, 0.00, P = 0.049), respectively. Conclusion: Exposure to PFNA and PFOA is negatively correlated with changes in male testosterone levels. This correlation suggests that we need to pay attention in the future to whether they are potential risk factors for male reproductive health.