The Effects of Exercise Training on Insulin Resistance in Patients With Coronary Artery Disease and Insulin Resistance, the Exercise, Coronary Artery Disease and Insulin Resistance (EXCADIR) Randomized Controlled Trial

Objectives To determine the effects of exercise training on insulin resistance in CAD subjects without diabetes, independent of changes in weight, diet, or the effect of acute exercise.

The study was approved by the Research Ethics Review Boards at London and Hamilton. All participants provided written and verbal informed consent.

Inclusion Criteria The study population will include men and women over 18 years of age identified from the practices of local cardiologists, whose fasting plasma glucose concentration is 5.4-7.7 mmol/L, and who had confirmed CAD (diagnosed on the basis of a previous myocardial perfusion study or cardiac catheterization, or a history of a myocardial infarction or coronary artery angioplasty or coronary artery bypass surgery).

Exclusion Criteria Individuals will be excluded if they had known type 1 or 2 diabetes, clinical heart failure, uncorrected significant valvular or congenital heart disease, significant obstructive pulmonary disease (forced expiratory volume in 1 sec / forced vital capacity < 0.5), uncontrolled hypertension (blood pressure > 220 / 120 mm Hg), participation in a regular exercise program within the preceding three months, inability to perform exercise training, atrial fibrillation, a permanent pacemaker or regularly used corticosteroid. Individuals who had experienced a myocardial infarction, unstable angina, coronary artery bypass graft surgery, or coronary artery angioplasty within the 3 months prior to study entry were also excluded. Furthermore, individuals were excluded if their run-in phase fasting blood glucose was < 5.4 mmol/L or > 11.1 mmol/L at 2 hours following the 75 gram oral glucose load.

Screening Visit Individuals who satisfied the above criteria underwent a screening visit comprising a full explanation of the study, appropriate history and physical evaluation by one of the study physicians (NGS or RSM). Height (m), weight (kg), waist and hip circumference (cm), and percentage body fat using bioelectrical impedance were measured. A 75g OGTT, using fasting and 2 hour samples, was then performed following an overnight (≥12 hour) fast. Participants satisfying the study selection criteria subsequently entered the run-in-phase.