Individuals with type 2 diabetes respond differently to exercise

Regular exercise helps prevent and delay the development of type 2 diabetes and its complications. Researchers at the Karolinska Institutet, together with a team of international scientists, have found that activation of the immune system in skeletal muscle during exercise may underlie the difference in how people with type 2 diabetes perceive and respond to exercise. These findings are published in the journal Progress of science.

People with type 2 diabetes often have a dysregulated inflammatory response in multiple tissues, which is associated with complications of the disease, such as insulin resistance and cardiovascular disease. In this study, researchers reveal a critical role for exercise-responsive cytokines, exerkines, in skeletal muscle development and growth in individuals with normal glucose tolerance or type 2 diabetes.

“In people with type 2 diabetes, an acute bout of exercise activates the immune system in a different and enhanced way compared to healthy volunteers”, says Professor Juleen R. Zierath of the Department of Molecular Medicine and Surgery and the Department of Physiology and Pharmacology at the Karolinska Institute, who led the study.

Untrained men diagnosed with type 2 diabetes were recruited along with healthy volunteers of similar age and body weight. The volunteers were asked to perform a single exercise session on a cycle ergometer. The research team collected blood and skeletal muscle biopsies in which they measured response to exercise.

The researchers found that several cytokines, molecules produced by the immune system in response to stress, were produced in the skeletal muscle of people with type 2 diabetes. The effect of those cytokines was tested in cultured cells to determine whether those molecules affect how in which skeletal muscle cells react to exercise.

Regular exercise decreases the inflammatory response

“Given the beneficial health effects of regular physical exercise on metabolism and skeletal muscle function, the exacerbated inflammatory response in people with type 2 diabetes is likely a beneficial response to acute exercise,” says Professor Juleen R. Zierath. “Activation of the immune system it will likely decrease if exercise is repeated regularly during training regimens,” he adds.

Reducing inflammation would be beneficial for glucose control and mitigating complications associated with type 2 diabetes.

“Now we need to understand how we can modulate the inflammatory answer to exercise. Doing so can enhance the benefits of exercise and help people better control type 2 diabetes with proper training protocols,” says Nicolas Pillon, Associate Professor at the Karolinska Institutet’s Department of Physiology and Pharmacology and first author of the paper.