A Disease Modification Effect of APOE E4 on the Association between Urinary Albumin Excretion and Cognition in Korean Adults

Background. No previous study examined a disease modifying effect of APOE E4 status on the association between the urinary albumin-to-creatinine ratio (UACR) and cognition. This study aimed to investigate whether APOE E4 modified the association in Korean adults. Methods. We performed a cross-sectional study in adults aged 45 to 74 who were living in Namwon City, Republic of Korea. Cognitive function was measured with the Korean version of modified Mini-Mental State Examination (K-mMMSE) and cognitive impairment was defined as scores falling below the 25th percentile of the K-mMMSE according to age, sex, and educational attainments. Results. A total of 10,190 participants (4006 men and 6184 women) were analyzed in the present study. Of these, 1698 subjects (16.7%) were APOE E4 carriers. The UACR values were negatively associated with the K-mMMSE scores, even after adjusting for potential confounders including age, sex, education, and vascular risk factors. APOE E4 modified the association significantly, resulting in a steeper decline of cognitive function with the increase in UACR in E4 carriers (P for interaction = 0.021). Conclusion. Higher UACR values were significantly associated with cognitive dysfunction in the general Korean population, with cognition in APOE E4 carriers being more severely affected by increased UACR.