Contribution of socioeconomic status at three lifecourse periods to late life memory function and decline: Early and late predictors of dementia risk.

Both early life and adult socioeconomic status (SES) predict late life level of memory; however, evidence is mixed on the relationship between SES and rate of memory decline. Further, the relative importance of different lifecourse periods for rate of late life memory decline has not been evaluated. We examined associations between lifecourse SES and late life memory function and decline. Health and Retirement Study participants (n = 10,781) were interviewed biennially from 1998-2012. SES measures for childhood (composite score including parents' educational attainment), early adulthood (high school or college completion), and older adulthood (income, mean age 66) were all dichotomized. Word list memory (non-responders retained via proxy assessments) was modeled via inverse probability weighted longitudinal models accounting for differential attrition, survival, and time-varying confounding. Compared to low SES at all three points (reference), stable high SES predicted the best memory function and slowest decline. High school completion had the largest estimated effect on memory (β = 0.19; 95% Confidence Interval = 0.15, 0.22), but high late life income had the largest estimated benefit for slowing declines (β for 10 year memory change = 0.35; 95% Confidence Interval = 0.24, 0.46). Both early and late life interventions are potentially relevant for reducing dementia risk by improving memory function or slowing decline.

http://www.ncbi.nlm.nih.gov/pubmed/28541410?dopt=Abstract