Selective impairment of frontal-executive cognitive function in African Americans with cardiovascular risk factors

OBJECTIVES: To determine whether a summary cardiovascular risk score is associated with an increased risk of frontal-executive cognitive impairment. DESIGN: Cross-sectional study. SETTING: Subjects were recruited from senior centers, senior housing complexes, and communities in the Boston metropolitan area. PARTICIPANTS: Forty-three predominantly female elderly African Americans. MEASUREMENTS: Cardiovascular risk factors were assessed during an interview and clinical examination. For each subject, the total number of cardiovascular (CV) risk factors was summed to compute a CV risk score. A battery of neuropsychological tests was administered that examined memory, visuospatial abilities, and frontal-executive functions. Cognitive test scores were transformed into domain-specific (memory, visuospatial, frontal-executive) composite z scores. Cognitive impairment for each composite z score was defined as performance less than the median for the study group. Multivariate logistic regression was used to examine the relationship between the CV risk score and the risk for cognitive impairment in the three cognitive domains of interest. RESULTS: After controlling for age and education, the CV risk score was associated only with frontal-executive cognitive impairment (odds ratio (OR) = 2.44, 95% confidence interval (CI) = 1.06-5.65). The CV risk score was not associated with the risk of memory (OR = 1.30, 95% CI = 0.64-2.67) or visuospatial impairment (OR = 1.49, 95% CI = 0.66-3.36). Greater CV risk scores were associated with an increased likelihood of having frontal-executive cognitive impairment. CONCLUSION: CV risk factors may exert a specific deleterious effect on frontal-executive cognitive abilities as opposed to memory or visuospatial functions. Associated executive dysfunction may compromise the ability of patients with CV risk factors to comply with recommendations for risk reduction.