Public Health

BACKGROUND: It has been reported that plasma oxidized low-density lipoprotein (ox-LDL) contributes to the atherosclerosis and triggers cardiovascular and cerebrovascular events. However, the relationship between plasma ox-LDL level and cognitive impairment had not been determined. This study investigated the association between plasma ox-LDL level and cognitive impairment among middle-aged and older population in China. METHOD: This was a community population-based cross-sectional study. A total of 1,406 participants (≥ 40 years) were recruited from a rural village in Xi'an, China using cluster-sampling method. The cognitive function was evaluated using the Mini-Mental State Examination (MMSE) and a battery of neuropsychological assessment, and cognitive impairment was diagnosed based on the criteria for mild cognitive impairment and dementia. Plasma ox-LDL levels were measured using ELISA. Restricted cubic spline analysis, multiple logistic regression, trend analysis and subgroup analysis wereperformed to investigate the relationships between plasma ox-LDL and cognitive impairment. RESULT: A total of 1,406 participants were included, of whom 112 (8.0%) met the criteria for cognitive impairment. Restricted cubic spline analysis did not identify a non-linear relationship between ox-LDL level and cognitive impairment (Pnon-linear=0.3167). Multivariable logistic regression showed that the incidence of cognitive impairment increased by 9.3% per 100 unit increase in the ox-LDL level (OR=1.093, 95% CI: 1.031-1.160, p = 0.003). Cognitive impairment risk was 1.704-fold higher in the highest ox-LDL tertile compared to the lowest ox-LDL tertile (OR=1.704, 95% CI: 1.015-2.861, p = 0.044). Interaction analysis revealed sex, age, total cholesterol, triglycerides, and low-density lipoprotein did not significantly modify the association between ox-LDL levels and cognitive impairment. CONCLUSION: Elevated ox-LDL levels are associated with a higher likelihood of cognitive impairment among Chinese adults aged ≥40 years. However, the causal relationship between plasma ox-LDL levels and cognitive impairment needs to be clarified further.