Association Between Immune Response to Cytomegalovirus and Cognition in the Health and Retirement Study.

Chronic infections and the subsequent immune response have recently been shown to be risk factors for cognitive decline and Alzheimer disease and related dementias (ADRD). While some studies have shown an association between cytomegalovirus (CMV), a chronic and highly prevalent infection, and cognition and/or ADRD, these studies have been limited by nonrepresentative and small samples. Using 2016 data on 5,617 adults aged 65 years or more from the Health and Retirement Study, we investigated the cross-sectional associations of both CMV serostatus and immunoglobulin G (IgG) antibody response with cognitive function using linear regression models adjusting for age, sex, race/ethnicity, and educational attainment. We further investigated potential effect-measure modification by educational attainment. Overall, both CMV seropositivity and higher IgG antibody response were associated with lower cognitive function, though the relationship was not statistically significant in adjusted models. Among participants with less than a high school diploma, CMV seropositivity and being in the first tertile of IgG response, relative to seronegative persons, were associated with lower scores on the Telephone Interview for Cognitive Status (-0.56 points (95% confidence interval: -1.63, 0.52) and -0.89 points (95% confidence interval: -2.07, 0.29), respectively), and the relationship was attenuated among those with higher education. Our results suggest that CMV may be a risk factor for cognitive impairment, particularly among persons with fewer educational resources.