Przybyla Jennifer, Houseman E Andres, Smit Ellen, Kile Molly L
School of Biological and Population Health, College of Public Health and Human Sciences, 101 Milam Hall, Corvallis, OR, 97330, USA.
Environ Health. 2017 Mar 7;16(1):19. doi: 10.1186/s12940-017-0227-3.
Polychlorinated biphenyls (PCBs) and metals (lead and cadmium) are neurotoxic and affect neurobehavioral performance. Yet little is known about the association between exposure to multiple neurotoxic compounds and cognitive functioning in older adults.
Using data from two consecutive cycles of the National Health and Nutrition and Examination Survey (1999-2002), path analysis was used to simultaneously evaluate the association between whole blood concentrations of 14 neurotoxic compounds and cognitive functioning measured by the Digit Symbol Coding Test of the Weschler Adult Intelligence Scale, 3 Edition in participants 60-84 years of age (N = 498). Effect modification was assessed for age (above/below the mean) and sex.
The final path model fit 5 compounds (i.e. PCB 74, PCB 118, PCB 146, PCB 153, and lead). After controlling for co-exposures and confounders, PCB 146 (β = -0.16, 95% CI: -0.29, -0.02, p = 0.02) and lead (β = -0.10, 95% CI: -0.20, -0.006, p = 0.04) were negatively associated with DSC scores in 60-84 year olds. Whereas, PCB 153 was positively associated with DSC scores (β =0.20, 95% CI: 0.05, 0.35; p = 0.01).
This cross-sectional analysis which controlled for collinear exposure to several neurotoxic compounds demonstrated an association between non-dioxin like polychlorinated biphenyl exposure, specifically PCB 146, and lower cognitive functioning, in older adults. Lead exposure was also weakly associated with lower cognitive functioning. Additional studies are needed to determine the causality of the observed associations.
多氯联苯（PCBs）和金属（铅和镉）具有神经毒性，会影响神经行为表现。然而，对于老年人接触多种神经毒性化合物与认知功能之间的关联，我们知之甚少。
利用美国国家健康与营养检查调查（1999 - 2002年）连续两个周期的数据，采用路径分析方法，同时评估14种神经毒性化合物的全血浓度与60 - 84岁参与者（N = 498）通过韦氏成人智力量表第3版数字符号编码测试所测量的认知功能之间的关联。对年龄（高于/低于均值）和性别进行效应修饰评估。
最终的路径模型纳入了5种化合物（即PCB 74、PCB 118、PCB 146、PCB 153和铅）。在控制了共同暴露因素和混杂因素后，PCB 146（β = -0.16, 95% CI: -0.29, -0.02, p = 0.02）和铅（β = -0.10, 95% CI: -0.20, -0.006, p = 0.04）与60 - 84岁人群的数字符号编码测试（DSC）得分呈负相关。而PCB 153与DSC得分呈正相关（β = 0.20, 95% CI: 0.05, 0.35; p = 0.01）。
这项控制了几种神经毒性化合物共线性暴露的横断面分析表明，在老年人中，非二噁英类多氯联苯暴露，特别是PCB 146，与较低的认知功能之间存在关联。铅暴露也与较低的认知功能存在弱关联。需要进一步的研究来确定所观察到的关联的因果关系。
