Whole-grain intake and carotid artery atherosclerosis in a multiethnic cohort: the Insulin Resistance Atherosclerosis Study.
BACKGROUND
Whole-grain intake has been shown to be 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 multiethnic cohort.


METHODS
This study evaluated 1178 participants in the Insulin Resistance Atherosclerosis Study. Baseline whole-grain intake was estimated on the basis of intake of dark breads, cooked cereals, and high-fiber cereals assessed with a validated food-frequency questionnaire. Bilateral carotid IMT was evaluated ultrasonographically, yielding 16 IMT measures at baseline and year 5. Multivariate 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 y and was 56% female. The baseline median whole-grain intake was 0.79 servings/d. Whole-grain intake was inversely associated with CCA IMT (beta +/- SE: -0.043 +/- 0.013, P = 0.005) and IMT progression (beta +/- SE: -0.019 +/- 0.011, P = 0.09) in models adjusted for demographics, energy intake, energy expenditure, cardiovascular disease risk factors, and medication use. This association was less significant for ICA IMT (beta +/- SE: -0.049 +/- 0.023, P = 0.05) and not significant for ICA IMT progression (beta +/- SE: -0.013 +/- 0.014, P = 0.35). The relation between whole-grain intake and CCA IMT remained significant after adjustment for mediating pathways (lipids, adiposity, and insulin resistance), nutrient constituents, and a principal components-derived healthy dietary pattern.


CONCLUSIONS
Whole-grain intake is inversely associated with CCA IMT, and this relation is not attributable to individual risk intermediates, single nutrient constituents, or larger dietary patterns.
Mellen
Philip B
PB
Department of Internal Medicine, Section of General Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. pmellen@wfubmc.edu
Liese
Angela D
AD
Tooze
Janet A
JA
Vitolins
Mara Z
MZ
Wagenknecht
Lynne E
LE
Herrington
David M
DM
D000328:Adult; D000368:Aged; D050197:Atherosclerosis / Q000473:pathology / Q000517:prevention & control*; D002340:Carotid Artery Diseases / Q000473:pathology / Q000517:prevention & control*; D017536:Carotid Artery, Common / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D015986:Confounding Factors, Epidemiologic; D004032:Diet; D004043:Dietary Fiber / Q000008:administration & dosage*; D018450:Disease Progression; D002523:Edible Grain; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019370:Observation; D011795:Surveys and Questionnaires; D017539:Tunica Intima / Q000033:anatomy & histology*; D018084:Ultrasonography, Interventional