Seminal Phthalate Metabolites, Semen Quality Parameters And Serum Reproductive Hormone Levels

Goal: To examine the associations between phthalate exposure encountered in the environment and semen quality and reproductive hormones among C hinese men, using phthalate metabolite levels in seminal plasma as biomarkers to estimate exposure status of target reproductive organs.Methods: Semen(n=687) and blood samples(n=342) were collected from men who presented to the Reproductive Center of Tongji Hospital to seek semen examination. Semen quality parameters and serum levels of reproductive hormone were assessed. Seminal plasma levels of 8 phthalate metabolites were determined using high-performance liquid chromatography and tandem mass spectrometry. Multivariate linear and logistic regression models were used to assess the associations between seminal plasma metabolites and semen quality parameters and serum reproductive hormone levels.Results: Increasing seminal plasma metabolites were associated with decreasing semen volume [mono-n-butyl phthalate(MBP), mono-(2-ethylhexyl) phthalate(MEHP), mono(2- ethyl-5-oxohexyl) phthalate(MEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate(MEHHP)], sperm curvilinear velocity [MEHP, monobenzyl phthalate(MBz P), the percentage of di-(2-ethylhexyl)-phthalate metabolites excreted as MEHP(%MEHP)] and straight- line velocity(MEHP, MBz P, %MEHP), and also associated with increasing percentages of abnormal sperm heads and tails(MBz P)(all Ptrend <0.05). No significant associations were observed between seminal plasma metabolites and serum reproductive hormone levels.Conclusion: Our results suggest that exposure to phthalates at environmental levelsmay impair human semen quality.