Phenols such as bisphenols, parabens, and triclosan are common environmental endocrine disruptors. Previous epidemiological studies have suggested that phenols may affect semen quality, but the results were inconsistent. In addition, most existing studies have been limited to the effects of a single chemical compound, ignoring the health effects of mixed exposure to multiple chemicals. Thus, we aimed to explore the associations between individual and mixed exposure to phenols and various semen quality parameters. In this study, a rapid and sensitive method was used to determine 18 phenolic compounds in urine samples of 799 volunteers who donated sperm samples to the Shanghai Human Sperm Bank. A spot urine sample was collected from each subject on the day of their clinic visit and stored at -20 ℃ until testing. Urine samples (200 μL) were extracted and added with 20 μL of an internal standard and 50 μL of β-glucuronidase solution. The mixtures were then incubated for 12 h at 37 ℃. After hydrolysis, the samples were extracted twice using ethyl acetate (500 μL). The concentrations of the 18 phenolic compounds were measured using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Semen quality parameters were analyzed using a computer-aided semen analyzer. Multiple linear regressions were used to detect the associations between individual phenol exposure and semen quality parameters. In addition, weighted quantile sum (WQS) models were used to explore the associations between mixed-phenol exposure and semen quality parameters. After adjusting for potential covariates, the results of multiple linear regressions showed that exposure to ethyl paraben (EtP) was significantly negatively associated with sperm concentration and total sperm count (P<0.05). In addition, exposure to mixed phenols was significantly associated with decreased sperm concentration; methyl paraben (MeP) and EtP were identified as the main contributors to this decrease. Thus, phenol exposure may be associated with decreased semen quality in young males, particularly with respect to sperm concentration and total sperm count.
酚类化合物是一类常见的环境内分泌干扰物,流行病学研究表明酚类化合物可能影响男性精液质量,但结果迥异。此外,现有的研究大多局限于单一酚类化合物的影响,忽视了现实情况中多种酚类物质混合暴露的健康影响,酚类化合物混合暴露与男性精液质量的关联仍需进一步探讨。本研究将所建立的高效液相色谱-串联质谱(HPLC-MS/MS)方法应用于大样本人群(799名向上海人类精子库捐赠精子样本的志愿者)尿样中18种酚类化合物的浓度测定,并探索了酚类暴露与精液质量之间的关联。通过测量精液指标(包含精子浓度、精子总数、精液体积和精子前向运动百分比),采用多元线性回归和加权分位数之和模型(WQS)分别探索单一酚类化合物暴露和多污染物混合暴露与精液质量参数间的关联。调整潜在的协变量后,多元线性回归模型发现尿液中对羟基苯甲酸乙酯(EtP)暴露与男性精子浓度和精子总数呈显著负相关(P<0.05);WQS混合暴露模型发现,酚类化合物混合暴露与精子浓度下降相关,其中对羟基苯甲酸甲酯与EtP是起主要影响作用的化合物。综上,酚类暴露可能与男性精液质量下降相关,主要表现在降低精子浓度和精子总数。
Keywords: high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS); male reproductive health; mixed exposure; phenols; semen quality.