OBJECTIVE To study the association between use of protein supplements (PS) and semen quality among young men. DESIGN Cross-sectional study. SETTING Not applicable PATIENT(S): We used data from the Fetal Programming of Semen Quality (FEPOS) cohort, which is a subsample of 778 men whose mothers enrolled in the Danish National Birth Cohort 1996-2002. INTERVENTION(S) Semen samples were collected from April 2017 to March 2019. Relative difference in semen characteristics according to self-reported PS use was estimated with negative binomial regression adjusting for lifestyle factors including exercise, body mass index, and use of anabolic steroids, and maternal and paternal factors potentially confounding the association between PS and semen quality. MAIN OUTCOME MEASURE(S) Negative binomial regression yielded the best fit and was used to estimate the percent difference with 95% confidence intervals in semen volume, sperm concentration, total sperm count, proportions of progressive, nonprogressive, and immotile sperm, and percentage of morphologically normal sperm in former and current users of PS relative to never users. RESULT(S) PS was used currently by 28% and formerly by 24% of participants. PS use was not associated with reduced semen quality in terms of semen volume, sperm concentration, total sperm count, morphology, or motility in either crude or adjusted analyses. CONCLUSION This study showed no association between use of PS and semen quality characteristics. Still, we encourage others to repeat the study, as even a small harmful effect would have a large impact on the population level because of the widespread use of PS among young men.

中文翻译：

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服用蛋白质补充剂的年轻健康男性的精液质量

目的 研究年轻男性蛋白质补充剂 (PS) 的使用与精液质量之间的关系。设计横断面研究。设置 不适用 患者：我们使用了来自精液质量胎儿规划 (FEPOS) 队列的数据，该队列是 778 名男性的子样本，其母亲在 1996-2002 年期间参加了丹麦国家出生队列。干预措施 精液样本于 2017 年 4 月至 2019 年 3 月收集。根据自我报告的 PS 使用情况，通过调整生活方式因素（包括运动、体重指数和合成代谢类固醇的使用）的负二项式回归估计精液特征的相对差异，母亲和父亲的因素可能会混淆 PS 和精液质量之间的关联。主要结果测量 负二项式回归产生最佳拟合，用于估计精液量、精子浓度、总精子数、进步、非进步和不动精子的比例以及 95% 置信区间的百分比差异。与从未使用过 PS 的人相比，以前和现在使用 PS 的人的形态正常的精子。RESULT(S) PS 目前被 28% 的参与者使用，之前被 24% 的参与者使用。在粗分析或调整分析中，PS 的使用与精液量、精子浓度、总精子数、形态或运动性方面的精液质量下降无关。结论 本研究表明使用 PS 与精液质量特征之间没有关联。尽管如此，我们还是鼓励其他人重复这项研究，