Patterns of cognitive function in middle-aged and elderly Chinese adults-findings from the EMCOA study

Background: The principal aim of this study was to demonstrate the gender-specific cognitive patterns among middle-aged and elderly Chinese adults, investigate the risk factors on global and domain-specific cognitive performance in men and women, respectively, and report demographically adjusted norms for cognitive tests. Methods: The Effects and Mechanism of Cholesterol and Oxysterol on Alzheimer's disease (EMCOA) study enrolled 4573 participants aged 50-70 years in three Chinese cities. All participants underwent an extensive neuropsychological test battery. Composite scores for specific domains were derived from principal component analysis (PCA). Multivariate linear regression models were used to determine gender-specific risk factors and demographically adjusted normative data. Results: Three cognitive domains of verbal memory, attention/processing speed/executive function, and cognitive flexibility were extracted. A female advantage in verbal memory was observed regardless of age, whereas men tended to outperform women in global cognition and attention/processing speed/executive function. The effects of education on women were more substantial than men for general cognition and attention/processing speed/executive function. For all the cognitive tests, regression-based and demographically adjusted normative data were calculated. Conclusions: There is a need for gender-specific intervention strategies for operationalizing cognitive impairment.