背景:目前,一些横断面研究发现,暴露于金属/类金属元素与男性生殖密切相关。然而,金属暴露对男性生殖的长期影响尚未被研究。
方法:2013年招募了796名志愿者,其次是2014年和2015年的第一次和第二次随访。尿液,精液,在每个阶段收集血液样本以检查尿液中的金属/类金属水平,精子参数,和性激素。最初,潜在类别轨迹模型(LCTM)用于分析尿金属的轨迹。随后,使用线性混合模型检查了尿液金属轨迹对精液参数和性激素的影响。最后,使用广义线性混合模型评估了尿金属轨迹对精液质量分类(正常或异常)的影响.
结果:在研究的18种金属/类金属中,轨迹由其中的6个形成(Li,Al,Fe,Zn,As,Rb).用线性混合模型和广义线性混合模型进一步分析发现Li与精液量呈负相关,精子活力(P<0.05)。与最小稳定轨迹组相比,最大下降轨迹组对精液质量有不利影响(OR=1.75,95CI:1.22,2.53)。Al与精子浓度呈负相关,精子总数,形态正常(P<0.05)。Rb与进行性运动呈正相关(P<0.05)。与低稳定轨迹组相比,高稳定轨迹组对精液质量具有保护作用(OR=0.66,95CI:0.49,0.90)。此外,Fe与卵泡刺激素(FSH)呈负相关(P<0.05),Rb与孕酮呈负相关(P<0.05)。
结论:我们为期三年的队列研究提供了新的证据,表明Li和Al对精液质量有负面影响,而Rb与有益作用相关。此外,Rb和Fe是性激素的内分泌干扰物。
BACKGROUND: At present, several cross-sectional studies have found that exposure to metal/metalloid elements is closely associated with male reproduction. However, the long-term effects of metal exposure on male reproduction have not been explored.
METHODS: In 2013, 796 volunteers were recruited, followed by first and second follow-ups in 2014 and 2015. Urine, semen, and blood samples were collected at each stage to examine urinary metal/metalloid levels, sperm parameters, and sex hormones. Initially, the latent class trajectory model (LCTM) was utilized to analyze the trajectories of urinary metals. Subsequently, the effects of urinary metal trajectories on semen parameters and sex hormones were examined using the linear mixed model. Finally, the impact of urinary metal trajectories on the classification of semen quality (normal or abnormal) was evaluated using the generalized linear mixed model.
RESULTS: Among the 18 metals/metalloids studied, trajectories were formed by 6 of them (Li, Al, Fe, Zn, As, Rb). Further analysis using the linear mixed model and the generalized linear mixed model revealed that Li was negatively correlated with semen volume, and sperm motility (P<0.05). The maximum-decreasing trajectory group had a detrimental effect on semen quality (OR=1.75, 95%CI: 1.22, 2.53) compared to the minimum-stable trajectory group. Al showed negative associations with sperm concentration, total sperm count, and normal morphology (P<0.05). Rb was positively associated with progressive motility (P<0.05). The high-stable trajectory group exhibited a protective effect on semen quality (OR=0.66, 95%CI: 0.49, 0.90) compared to the low-stable trajectory group. Additionally, Fe was observed to have a negative relationship with follicle-stimulating hormone (FSH) (P<0.05), and Rb exhibited a negative correlation with progesterone (P) (P<0.05).
CONCLUSIONS: Our three-year cohort study provides new evidence that Li and Al have a negative impact on semen quality, whereas Rb is associated with beneficial effects. Additionally, Rb and Fe are endocrine disruptors of sex hormones.