Type 2 diabetes is increasing world-wide due to obesity caused by physical inactivity and generally poor lifestyle. Patients with diabetes have more than 2-fold increased risk of developing terminal heart disease (heart failure) and heart failure patients with diabetes have a greater risk dying of arrhythmias than heart failure patients without diabetes. We all know that exercise training is good and that regular exercise prevents the risk of diabetes and heart disease. But what happens if you already have diabetes and have suffered a myocardial infarction?
To answer this question Natale Rolim and collaborators exercised obese, type 2 diabetic mice with myocardial infarction at a high-intensity interval training for 6 weeks. The mice that had both diabetes and myocardial infarction had a greater chance of arrhythmia’s and had worse cardiac function compared to mice with myocardial infarction only. These functional changes were associated with poor regulation of calcium in the heart. Calcium ions are necessary for cardiac contraction and a tight regulation of calcium ions determines the rate of contraction and relaxation, but dysregulation can also cause arrhythmias. Exercise training in obese and diabetic mice with myocardial infarction improved calcium regulation and reduced the chance of arrhythmias.
Effective drug therapy for patients with heart disease in combination with diabetes is lacking. Therefore should exercise training be of great importance. There exist a lot of training programs, and in our blog and at the CERG web page effective training programs are described. Individuals with heart disease or at risk of heart disease should always consult with their primary care physician before starting a training program.
Tomas Stølen, researcher at CERG