Background

Essential elements such as iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), selenium (Se), rubidium (Rb), strontium (Sr), and molybdenum (Mo) are necessary for reproductive health. However, their associations with human semen quality remain inconclusive.

Objectives

To investigate the associations of urinary Fe, Co, Cu, Zn, Se, Rb, Sr, and Mo concentrations with semen quality in healthy men screened as potential sperm donors and identify critical windows of susceptibility.

Methods

1428 healthy men provided 3766 urine and 6527 semen samples, which were measured for urinary essential element concentrations and sperm quality parameters, respectively. Linear mixed models and cubic spline curves were used to evaluate associations between urinary essential elements and semen quality. Multiple informant models were used to identify potential critical windows of susceptibility.

Results

Linear mixed models and cubic spline curves showed positive dose–response relationships between urinary Zn and sperm concentration and total count and between urinary Mo and total sperm count [all False Discovery Rate (FDR) adjusted p-value for trend < 0.05]. In the multiple-element linear mixed models, the men in the highest versus lowest quartiles of urinary Zn and Mo had a higher sperm concentration of 17.5% (95% CI: 2.8%, 34.2%; p-value for trend = 0.006) and total sperm count of 18.3% (95% CI: 1.4%, 38.0%; p-value for trend = 0.027), respectively. Urinary Zn was also positively associated with total sperm count in a dose-dependent manner (p-value for trend = 0.036), though the percentile difference in total sperm count between men in the highest and lowest quartile was not statistically significant (16.4%, 95% CI: −1.7%, 37.9%). These associations appeared to be stronger when urinary Zn and Mo were measured at 0–9 days before the date of semen examination (i.e., corresponding to epididymal storage).

Conclusions

Higher urinary Zn and Mo, particularly during the period of epididymal storage, were associated with greater sperm production.

中文翻译：

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在筛选为潜在精子捐献者的 1428 名健康男性中确定对精液质量基本要素的易感性窗口

背景

铁 (Fe)、钴 (Co)、铜 (Cu)、锌 (Zn)、硒 (Se)、铷 (Rb)、锶 (Sr) 和钼 (Mo) 等基本元素是生殖健康所必需的。然而，它们与人类精液质量的关联仍然没有定论。

目标

调查作为潜在精子捐献者的健康男性的尿液 Fe、Co、Cu、Zn、Se、Rb、Sr 和 Mo 浓度与精液质量的关联，并确定易感性的关键窗口。

方法

1428 名健康男性提供了 3766 份尿液和 6527 份精液样本，分别测量了尿液必需元素浓度和精子质量参数。线性混合模型和三次样条曲线用于评估尿液基本元素和精液质量之间的关联。多个线人模型用于识别潜在的易感性关键窗口。

结果

线性混合模型和三次样条曲线显示尿锌与精子浓度和总计数之间以及尿钼与总精子计数之间的正剂量反应关系 [所有错误发现率 (FDR) 调整后的p值趋势 < 0.05]。在多元素线性混合模型中，尿锌和钼的最高四分位数与最低四分位数的男性精子浓度较高，为 17.5%（95% CI：2.8%、34.2%；趋势的p值 = 0.006）和总精子数分别为 18.3%（95% CI：1.4%、38.0%；趋势的p值 = 0.027）。尿锌也以剂量依赖性方式与总精子数呈正相关（p- 趋势值 = 0.036），尽管最高和最低四分位男性之间精子总数的百分位数差异无统计学意义（16.4%，95% CI：-1.7%，37.9%）。在精液检查日期前 0-9 天（即对应于附睾储存）测量尿锌和钼时，这些关联似乎更强。

结论

较高的尿锌和钼，特别是在附睾储存期间，与更多的精子产生有关。