C‐reactive protein, APOE status, and cognitive impairment in older adults.

Background: The aim of this study was to investigate the impact of Apolipoprotein ε4 (APOEε4) on the possible relationship between high sensitive serum CRP (hsCRP) and risk of incident dementia, Alzheimer's disease (AD), and cognitive impairment over seven years in a longitudinal, population based study of community dwelling older adults. Method: Serum hsCRP was measured at baseline in 304 dementia‐free individuals aged 65‐79 years derived from the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study. Participants were re‐examined seven years later, and global cognition, episodic memory, executive functioning, verbal expression, and psychomotor speed were assessed both at baseline and at follow‐up. Incident dementia was diagnosed using DSM‐IV criteria. Multiple linear regression and logistic‐regression models were used to investigate the association of serum hsCRP and its interaction with APOEε4 status on cognitive performance and incident dementia at follow‐up, after adjusting for several potential confounders, including common vascular risk factors. Result: After adjustment for age, sex, education, duration of follow‐up, systolic blood pressure, diastolic blood pressure, body mass index, prevalent stroke, and smoking status, odds ratio (95% confidence intervals (CI)) was 3.02 (1.18 – 7.73) for those who had at least one alle of APOEε4 compared to those who did not. The odds ratio (95%CI) for incident dementia was 1.00 (0.96 – 1.04) oer unit increase in hsCRP. No associations between hsCRP and cognitive impairment seven years later was detected. However, raised hsCRP values were related to worse performance in episodic memory seven years later in participants who had at least one allele of APOEε4 (β (standard error): ‐0.005 (0.002); p = 0.025). Conclusion: Raised values of hsCRP is associated with higher risk of cognitive impairment seven years later among individuals who carry at least one allele of APOEε4. Randomized controlled trials are needed to determine this issue. [ABSTRACT FROM AUTHOR]