Carbohydrate-enriched diet impairs cardiac performance by decreasing the utilization of fatty acid and glucose

Aims: We hypothesized that a high-carbohydrate diet affects the cardiac performance by interfering in the metabolic steps involved in energy transfer in this organ. To verify this, we investigated the myocardial utilization of different substrates and contractile function in rats fed a high-carbohydrate diet, under normal flow and ischemia.Methods and Results: Male Wistar rats were fed over 9 days with standard (39.5% carbohydrate, 8% fiber) or high-carbohydrate diet (58% carbohydrate) and, afterwards, their cardiac function was examined using isolated heart preparations. The high-carbohydrate diet decreased the activity of the lipoprotein lipase, utilization of fatty acids, expression of the gene of peroxisome proliferator-activated receptor α and its target enzymes. In addition, decreased GLUT4 mass, glucose uptake, glycogen content and glycolytic intermediates were also observed. High-carbohydrate hearts displayed weaker activation of the glycolytic pathway during ischemia, according to minor productio...