A high carbohydrate meal yields a lower ischemic threshold than a high fat meal in patients with stable coronary disease

Objective: To assess the ischemic threshold and stress-induced left ventricular dysfunction after high fat (HFM) and high carbohydrate (HCM) meals in patients with stable coronary disease. Methods: Twelve patients (68 +/- 7 years) underwent stress (treadmill exercise testing) echocardiography after fasting (8 h), after HFM and HCM (2 h). Time to 1 mm ST-segment depression (time to 1 mm) and stress wall motion score index (WMSI) were evaluated. Before eating and just before exercise testing glucose, insulin, triglycerides, total cholesterol and FFA levels were measured. Results: Results are expressed as medians (Q1-Q3). HFM did not affect exercise variables compared to fasting, whereas HCM reduced the ischemic threshold [time to 1 mm from 376 (343-493) to 297 (180-420) s, p = 0.003]. Compared to fasting [1.47 (1.31-1.66)], stress WMSI was higher after HCM [1.56 (1.44-1.69)] (p = 0.04) but not after HFM [1.56 (1.30-1.63)]. Glycemia and insulinemia were significantly higher after HCM, compared to fasting and HFM. Conclusions: In patients with coronary disease, exercise testing after a high carbohydrate meal results in a lower ischemic threshold and greater ischemia magnitude. Conversely, compared to fasting, a high fat meal does not induce additional detrimental effects. Hyperglycemia and hyperinsulinemia were the only metabolic determinants identified as potential metabolic mechanisms of this phenomenon. (C) 2009 Elsevier Ireland Ltd. All rights reserved.