Abstract P197: Dietary Quality Determined by Healthy Eating Index-2015 and Endothelial Function in Healthy Adults

Abstract

The Healthy Eating Index (HEI) is a measure of diet quality based on Dietary Guidelines for Americans and developed in collaboration with the US Department of Health and Human Services and the US Department of Agriculture. Clinical interest in HEI has increased due to its association with obesity, inflammatory biomarkers and risk of coronary heart disease and stroke. Indeed, higher HEI-2015 score has been linked with reduced cardiovascular risk, morbidity, and mortality. Endothelial dysfunction, particularly impaired endothelium-dependent vasodilation, is a central etiological factor underlying cardiovascular risk and events. We and others have previously demonstrated that diets high in saturated fat and other proatherogenic diets are associated with endothelial vasodilator dysfunction. It is currently unknown whether HEI-2015 dietary score is associated with endothelial function. If so, assessing dietary quality based on HEI-2015 may provide targeted nutritional guidance for enhancing vascular health and mitigating cardiovascular risk. The aim of this study was to determine whether HEI-2015 score is associated with endothelial vasodilator function in healthy adults. Using data from 4-day dietary records, HEI-2015 scores were determined in 103 adults (65 M/38 F; age 44-68 years) free of overt cardiometabolic disease. The HEI-2015 score is based on 13 components summed to yield a total score from 0 to 100; higher score representing higher diet quality. The adults were stratified by HEI-2015 score quartiles: Q1: HEI < 52.5 (n=25; 23 M/2 F); Q2: HEI 52.6-59.1 (n=26; 14 M/12 F); Q3: HEI 59.2-66.0 (n=26; 15 M/11 F); and Q4: HEI > 66.0 (n=26; 13 M/13 F). Endothelium-dependent vasodilation was determined by forearm blood flow (FBF) (via plethysmography) responses to intra-arterial infusion of acetylcholine (ACh: 4.0, 8.0, and 16.0 μg/100 mL tissue/min) and sodium nitroprusside (NTP: 1.0, 2.0, and 4.0 μg/100 mL tissue/min). There were no significant differences in endothelium-dependent vasodilation across the HEI-2015 score quartiles. FBF blood responses to ACh were remarkably similar between Q1 (5.1±0.2 to 13.0±0.7 mL/100 mL tissue/min), Q2 (4.3±0.2 to 12.1±0.7 mL/100 mL tissue/min), Q3 (4.4±0.2 to 13.0±0.7 mL/100 mL tissue/min) and Q4 (4.5±0.2 to 14.4±0.6 mL/100 mL tissue/min). Moreover, HEI scores were not significantly associated with the vasodilator response to either ACh (r=0.15, P=0.13) or NTP (r=-0.04; P=0.72). In summary, although diet quality determined by HEI-2015 score has been shown to be associated with increased risk of cardiovascular disease and events, HEI-2015 was not associated endothelial function in mid-life and older adults. Given the established experimental and pathophysiological evidence linking between diet, endothelial vasodilator function and cardiovascular risk, HEI-2015 score is not a sensitive dietary indicator/biomarker of vascular function.