Department of Human Ecology, The University of Tokyo, Tokyo, Japan.
International University of Health and Welfare, Otawara, Japan.
Biol Trace Elem Res. 2024 Jun;202(6):2488-2500. doi: 10.1007/s12011-023-03868-w. Epub 2023 Sep 27.
Elevated sperm mitochondrial DNA copy number (mtDNAcn) is associated with damage to sperm and poorer measures of semen quality. Exposure to cadmium (Cd) can increase oxidative stress and damage sperm mitochondria. The adverse effects of Cd can potentially be reduced by sufficient selenium (Se). The objective of this study was to examine the associations between sperm mtDNAcn and urinary concentrations of Cd and Se, as well as the Cd/Se molar ratio. Participants were recruited from patients who sought infertility treatment at two hospitals in Japan. Urine and semen specimens and self-administered questionnaires were collected on the day of recruitment. Sperm mtDNAcn was measured in extracted sperm DNA by multiplex real-time qPCR. Urinary Cd and Se concentrations were measured using inductively coupled plasma mass spectrometry, and their molar weights were calculated to obtain the Cd/Se molar ratio. Linear regression was used to estimate associations after adjusting for age, body mass index, smoking, drinking, exercise, varicocele, and hospital of recruitment. Sperm mtDNAcn showed statistically insignificant associations with creatinine-adjusted concentrations of urinary Cd (β = 0.13, 95% CI -0.18, 0.44) and Se (β = -0.09, 95% CI -0.54, 0.35), and Cd/Se molar ratio (β = 0.12, 95% CI -0.13, 0.37). The current study found no evidence of an association between mtDNAcn and urinary concentrations of Cd or Se, or the Cd/Se molar ratio.
精子线粒体 DNA 拷贝数升高（mtDNAcn）与精子损伤和精液质量下降有关。镉（Cd）暴露会增加氧化应激并损害精子线粒体。足够的硒（Se）可以降低 Cd 的不良影响。本研究的目的是研究精子 mtDNAcn 与尿中 Cd 和 Se 的浓度以及 Cd/Se 摩尔比之间的关系。参与者是从日本两家医院寻求不孕治疗的患者中招募的。在招募当天收集了尿液和精液标本以及自我管理的问卷。通过多重实时 qPCR 从提取的精子 DNA 中测量精子 mtDNAcn。使用电感耦合等离子体质谱法测量尿 Cd 和 Se 的浓度，并计算其摩尔质量以获得 Cd/Se 摩尔比。线性回归用于调整年龄、体重指数、吸烟、饮酒、运动、精索静脉曲张和招募医院后估计关联。精子 mtDNAcn 与肌酐校正的尿 Cd（β=0.13，95%CI -0.18，0.44）和 Se（β=-0.09，95%CI -0.54，0.35）浓度以及 Cd/Se 摩尔比（β=0.12，95%CI -0.13，0.37）呈统计学上无显著关联。本研究没有发现 mtDNAcn 与尿 Cd 或 Se 浓度或 Cd/Se 摩尔比之间存在关联的证据。
