Heads and Hearts: Interactive Relations of Left Ventricular Mass and Sociodemographic Factors on Cognitive Outcomes in Urban Dwelling African American and White Adults.

Abstract

Degree of hypertrophy of the left ventricle, indexed by greater LVM, is a measure of subclinical CVD that is prognostic of cardiovascular morbidity and mortality. Much is known about the relations of select subclinical CVD indices to cognitive function, yet relatively little is known about LVM-cognition associations, particularly among disenfranchised groups. Participants were 1,107 African American (AA) and White, urban dwelling adults (mean age = 52.19, 60.4% female, 56.5% AA, 34% below 125% of the poverty line) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Exclusions were stroke, dementia, other neurological disease, HIV+ status, and known CVD. An echocardiogram measured key left ventricular dimensions to calculate LVM. Cognitive performance was assessed by: Digits Forward and Backward, Trail Making Test (TMT) A, and TMT-B, Brief Test of Attention (BTA), Benton Visual Retention Test, the California Verbal Learning Test, and semantic fluency (animals). Multivariable linear regression examined the interactive relations of LVM, race, and poverty status to each outcome. Covariates were added hierarchically in three steps: 1) age, sex, and education (base model), 2) body mass index, smoking status, diabetes diagnosis, and hypertension 3) left ventricular ejection fraction. There were no significant three-way or two-way interactions of LVM, race, and poverty status for any cognitive outcome. Backward elimination identified significant main effects of LVM on the BTA across all adjusted models (1st: B = -.004, p =.002; 2nd: B = -.004, p =.019; 3rd: B = -.004, p =.019) and on TMT-B in the second and third models (2nd: B = .000, p =.024; 3rd: B = .000, p =.037). Greater LVM was associated with lower levels of performance on both measures. To our knowledge, this was the first study that examined interactive relations of LVM, race, and poverty status to multiple domains of cognitive function. Results revealed that, irrespective of race or poverty status, those with higher LVM were vulnerable to poorer performance on select tests of executive function. However, no associations were noted for basic attention, memory, working memory, or perceptuo-motor speed. These findings may reflect the early emergence of neurocognitive changes associated with enhanced cardiovascular risk in this largely middle-aged sample.