[The interaction between plasma aluminum concentration and schooling year on cognitive function]

Objective: To explore the effect of the interaction between plasma aluminum concentration and schooling year on cognitive function, it provides the basis for early identification of its damaging effect. Methods: From October to December, 2014, 1114 on-the-job aluminum exposed workers in a large aluminum factory in Shanxi Province were investigated. The plasma aluminum concentrations were measured by inductively coupled plasma-mass spectrometry (ICP-MS) as an internal exposure indicator. The subjects were divided into low, medium, and high aluminum exposure group based on the blood lead concentration levels. The general information was collected with a self-designed questionnaire, and their cognitive function was evaluated with the mini-mental state examination and the clock drawing test. The interaction between plasma aluminum concentration level and education level was analyzed by using unconditional logistic regression fitting multiplication model and cross analysis fitting addition model. Results: The average level of plasma aluminum of the subjects was 21.68 (10.51, 45.78) μg/L. The detection rate of cognitive impairment was 19.9%. The influencing factors of cognitive function were plasma aluminum concentration, age, education level and marital status, among which high schooling year, and being married were the protective factors (all P<0.05), plasma aluminum concentration, and age were the risk factors (all P<0.05) ; After adjusting the confounding factors, such as age, marital status, schooling year, income level, smoking, and drinking, logistic regression model and the multiple linear regression model showed that there was a dose response relationship between plasma aluminum concentration and cognitive impairment. With the increase of plasma aluminum concentration, the score gradually decreased, and the risk of cognitive impairment increased (P(trend)<0.05) ; There were multiplicative interaction (AOR=2.15, 95%CI: 1.10-4.19) and additive interaction (RERI=5.38, 95%CI: 2.60-8.16; AP=0.65, 95% CI: 0.51-0.80; S=3.88, 95% CI: 2.00-7.56) between plasma aluminum concentration and low schooling year on cognitive function. Conclusion: There was a dose-response relationship between aluminum exposure and cognitive impairment. There was an interaction between aluminum exposure and low schooling year. When both of them worked together, the risk of cognitive impairment increases.