Effects of Low Versus High Carbohydrate Diet During Rehabilitation on Cardiovascular Function and Metabolism in Type 2 Diabetes

Overview

Compared to the traditional low fat diet for overweight patients with type 2 diabetes, recent evidence shows that low carbohydrate/high protein diets lower triglycerides and postprandial glucose levels more effectively. However, it is not known, whether this diet can also improve the subclinically impaired myocardial function in type 2 diabetes. This prospective parallel group and cross over design study compares the effects of a low glycemic and insulinemic diet (LOGI®) with an isocaloric traditional low fat diet during a three weeks rehabilitation programme with aerobic exercise for overweight type 2 diabetes patients testing the hypothesis, that the low carbohydrate diet improves myocardial function and insulin resistance.

This is a single center, short term therapy controlled and prospective study with blinded analyses of the ultrasound data in 41 patients with type 2 diabetes either on dietary control or oral antidiabetic medication. After recruitment and informed consent, patients are randomized to two treatment arms matched for age and concomittant antidiabetic and cardiovascular medication In one treatment arm, the diet is based on the LOGI components: 25% low glycemic index carbohydrates, 30% protein, 45% fat, taken for 3 weeks combined with aerobic exercise, while in the other treatment arm, the isocaloric traditional low fat diet is based on 55% mixed glycemic index carbohydrates, 20 % protein and 25% fat taken for three weeks and combined with the same aerobic exercise protocoll but followed by a two weeks period with LOGI diet and maintained exercise. In both treatment arms, antidiabetic and antihypertensive medication are maintained and/or adapted as necessary and recorded. All patients receive life style instructions and are updated in their skills of measuring quantity of foods and designing diet plans based on food groups. Laboratory, clinical and ultrasound investigations are performed before and at the end of the three weeks programme and, in the cross over group, also at the end of the subsequent diet programme.