Abstract 4118: Whole Grain Intake and Carotid Artery Atherosclerosis in a Multi-Ethnic Cohort: The Insulin Resistance Atherosclerosis Study
Background: Whole grain intake has been inversely associated with cardiovascular events, but an association with atherosclerosis is less well established.
Objective: We sought to evaluate the association of whole grain intake with carotid intimal medial thickness (IMT) and IMT progression in a multi-ethnic cohort.
Design: This study evaluated 1178 participants in the Insulin Resistance Atherosclerosis Study. Baseline whole grain intake was estimated based on intake of dark breads, cooked cereals, and high-fiber cereals assessed in a validated food frequency questionnaire. Bilateral carotid IMT was evaluated ultrasonographically, yielding sixteen IMT measures at baseline and year five. General linear mixed models evaluated the independent association of whole grain intake with common carotid artery (CCA) and internal carotid artery (ICA) IMT and IMT progression.
Results: The cohort had a mean (SD) age of 55.2 (8.4) years and was 30% African-American, 32% Hispanic, and 38% non-Hispanic white. The baseline median whole grain intake was .79 servings/day. Whole grain intake was inversely associated with CCA IMT [β(SE): -.046 (.014), p=.004] and IMT progression [β: -.021 (.012), p=.08] in models adjusted for demographics, energy intake/expenditure, cardiovascular risk factors, and medication use. This association was less significant for ICA IMT [β: -.051 (.024), p=.06] and not significant for ICA IMT progression [β: -.015 (.014), p=.31]. The relationship between whole grain intake and CCA IMT remained significant after adjustment for intermediate pathways (LDL, insulin sensitivity (SI), waist circumference) (p= .008, .02, .01), nutrient constituents (fiber, Mg++) (p= .003, .03), and a principal components-derived ‘healthy’ dietary pattern (p=.002).
Conclusions: Whole grain intake is inversely associated with common carotid IMT, and this relationship is not attributable to individual risk intermediates, single nutrient constituents, or larger dietary patterns.