Increased myocardial ischemia after food is not explained by endothelial dysfunction

• Published in: The American heart journal 2002-11, Vol.144 (5), p.E8-E8
• Main Authors: Edwards, Colin, Stewart, Ralph A.H., Ramanathan, Krishnan, West, Teena M., French, John K., White, Harvey D.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Angina Pectoris - etiology; Angina Pectoris - physiopathology; Brachial Artery - physiopathology; Coronary Disease - etiology; Coronary Disease - physiopathology; Coronary vessels; Cross-Over Studies; Diet, Atherogenic; Diet, Fat-Restricted; Dietary Fats - adverse effects; Double-Blind Method; Electrocardiography; Endothelium, Vascular - physiopathology; Exercise; Exercise Test; Female; Heart attacks; Humans; Male; Meals; Middle Aged; Regional Blood Flow; Time Factors; Vasodilation - physiology
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1067/mhj.2002.125624

Background Recent studies suggest that a high-fat meal can impair endothelial function. The aim of this study was to determine whether greater myocardial ischemia after either a low-fat or a high-fat meal is associated with an increase in brachial artery endothelial dysfunction. Methods Twenty subjects with coronary artery disease and ≥1-mm ST-segment depression during exercise were studied. In a randomized, double-blind, crossover design, ST-segment changes during treadmill exercise and brachial artery diameter and flow-mediated dilation were measured before and 3 hours after a low-fat milkshake meal or the same meal supplemented with 64 grams of cooked fat. Results After the low-fat but not the high-fat meal, resting brachial artery diameter decreased (before meal 4.72 ±0.50 mm, after low fat meal 4.62 ±0.49 mm, P =.001; after high fat meal 4.70 ±0.51 mm, not significant). High-flow brachial artery diameter was similar before (4.81 ± 0.48 mm) and after the low-fat (4.82 ± 0.48 mm) and high-fat (4.84 ± 0.48 mm) meals (P >.05 for all). Brachial artery flow-mediated dilation was not impaired after either meal. Exercise duration decreased more after the low-fat meal (mean change 39 seconds, 95% CI −14 to −63 seconds, P =.004) than after the high-fat meal (−7 seconds, 95% CI +19 to −34 seconds, not significant). ST-segment depression during equivalent exercise was greater after compared with before both meals (before meals 1.03 ± 0.69 mm, after low fat 1.27 ± 0.80 mm, P =.03; after high fat 1.24 ± 0.74 mm, P =.04). Conclusions Increased myocardial ischemia after food is caused by mechanisms other than endothelial dysfunction and by meal components other than cooked fat. (Am Heart J 2002;144:e8.)