The relationships between plasma advanced glycation end products level and cognitive function in middle-aged and elderly Chinese subjects

Objectives: To determine the relationships between circulating representative advanced glycation end products (AGEs) and cognitive performance in middle-aged and elderly Chinese adults.Method: A cross-sectional study with 1834 participants were included. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE). Plasma free AGEs including N epsilon-carboxymethyl-L-lysine (CML), N epsilon-(1-carboxyethyl) lysine (CEL), S-carboxymethyl-L-cysteine (CMC) and N delta-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Multivariate adjusted linear and logistic regression analysis were used to explore the associations between plasma AGEs and cognitive function.Results: The prevalence of mild cognitive impairment (MCI) was 17.94%. Plasma CMC and MG-H1 level were negatively associated with MMSE score (beta = -0.42, p < 0.001 for all) in the multivariate linear regression analysis. In the multivariate logistic regression analysis, compared to the lowest tertile, participants within the highest tertile of CMC and MG-H1 had increased risk of MCI [ORs (95% CI): 1.62 (1.21-2.17), P trend <0.001, and ORs (95% CI): 1.30 (0.97-1.76), P trend = 0.069, respectively]. In addition, the weighted quantile sum (WQS) index was negatively associated with MMSE (beta = -0.48, P < 0.001) and increased risk of MCI [ORs (95% CI): 1.35 (1.20-1.52), P < 0.001].Conclusion: Combined exposure of plasma free AGEs including CML, CEL, CMC and MG-H1 were associated with increased risk of cognitive impairment. Plasma CMC and MG-H1 might the main contributors for cognitive impairment, while further longitudinal studies are required to verify the associations.