Effects of Gene and Plasma Tau on Cognitive Impairment in Rural Chinese Population

Background: Sufficient attention was not paid to the effects of microtubule-associated protein tau (MAPT) and plasma tau protein on cognition. Objective: A total of 3072 people in rural China were recruited. They were provided with questionnaires, and blood samples were obtained. Methods: The MMSE score was used to divide the population into cognitive impairment group and control group. First, logistic regression analysis was used to explore the possible factors influencing cognitive function. Second, 1837 samples were selected for SNP detection through stratified sampling. Third, 288 samples were selected to test three plasma biomarkers (tau, phosphorylated tau, and Aβ-42). Results: For the MAPT rs242557, people with AG genotypes were 1.32 times more likely to develop cognitive impairment than those with AA genotypes, and people with GG genotypes were 1.47 times more likely to develop cognitive impairment than those with AG phenotypes. The plasma tau protein concentration was also increased in the population carrying G (P = 0.020). The plasma tau protein was negatively correlated with the MMSE score (P = 0.004). Conclusion: The mutation of MAPT rs242557 (A > G) increased the risk of cognitive impairment and the concentration of plasma tau protein.