Wu Luli, Xin Ye, Zhang Junrou, Yang Xin, Chen Tian, Niu Piye
Department of Occupational Health and Environmental Health, School of Public Health, Capital Medical University, 100069 Beijing, China.
Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, 100069 Beijing, China.
Environ Health (Wash). 2024 Jul 9;2(12):865-874. doi: 10.1021/envhealth.4c00071. eCollection 2024 Dec 20.
Exposure to metals may potentially impact cognitive health in the elderly; however, the evidence remains ambiguous. The specific role of serum folate in this relationship is also unclear. We aimed to evaluate the individual and joint impact of metals on cognition in the elderly from the United States and explore the potential mediating effect of serum folate. Data from the NHANES 2011-2014 were used, with inductively coupled plasma mass spectrometry (ICP-MS) employed to measure blood metal concentrations. Cognitive function was assessed using tests for immediate, delayed, and working memory: Immediate Recall test (IRT), the Delayed Recall test (DRT), the Animal Fluency test (AFT), and the Digit Symbol Substitution test (DSST). Generalized linear regression models (GLMs), Bayesian kernel machine regression model (BKMR), and quantile g-computation (QG-C) models were used to assess associations between metals (lead, cadmium, mercury, selenium, manganese) and cognition, with mediation analyses examining serum folate's involvement in metal effects. This study included 2002 participants aged ≥60. GLMs revealed the negative association between cadmium and the z-scores of IRT (β: -0.17,95% CI: -0.30, -0.04) and DSST (β: -0.15,95% CI: -0.27, -0.04), with negative effects also observed in the BKMR and QG-C models. Selenium displayed significantly positive association with cognition across various statistical models, including GLMs, QG-C, and BKMR. Serum folate played a mediating role in the effects of cadmium and selenium exposure on DSST z-scores, with a proportion of mediation of 17% and 10%, respectively. Our study assessed the impact of metal mixtures on cognition in the elderly population, finding that high selenium level was strongly associated with better cognitive performance, while cadmium was associated with lower cognitive function scores. Serum folate might partially mediate the association between cadmium, selenium, and DSST z-scores.
接触金属可能会对老年人的认知健康产生潜在影响；然而，证据仍然不明确。血清叶酸在这种关系中的具体作用也不清楚。我们旨在评估金属对美国老年人认知的个体和联合影响，并探讨血清叶酸的潜在中介作用。使用了2011 - 2014年美国国家健康与营养检查调查（NHANES）的数据，采用电感耦合等离子体质谱法（ICP - MS）测量血液中的金属浓度。使用即时、延迟和工作记忆测试来评估认知功能：即时回忆测试（IRT）、延迟回忆测试（DRT）、动物流畅性测试（AFT）和数字符号替换测试（DSST）。使用广义线性回归模型（GLMs）、贝叶斯核机器回归模型（BKMR）和分位数g计算（QG - C）模型来评估金属（铅、镉、汞、硒、锰）与认知之间的关联，并通过中介分析研究血清叶酸在金属效应中的作用。本研究纳入了2002名年龄≥60岁的参与者。GLMs显示镉与IRT的z分数（β： - 0.17，95%置信区间： - 0.30， - 0.04）和DSST的z分数（β： - 0.15，95%置信区间： - 0.27， - 0.04）呈负相关，在BKMR和QG - C模型中也观察到了负面影响。在包括GLMs、QG - C和BKMR在内的各种统计模型中，硒与认知呈显著正相关。血清叶酸在镉和硒暴露对DSST z分数的影响中起中介作用，中介比例分别为17%和10%。我们的研究评估了金属混合物对老年人群认知的影响，发现高硒水平与更好的认知表现密切相关，而镉与较低的认知功能得分相关。血清叶酸可能部分介导了镉、硒与DSST z分数之间的关联。
