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.