Why do type 2 diabetes patients often suffer exercise intolerance and poor blood sugar control?

Dr Lewan Parker is examining type 2 diabetes and the role of poor blood flow through the smallest blood vessels in the body (muscle microvascular dysfunction).

Many patients with type 2 diabetes are unable to exercise (exercise intolerance), which is linked to worsening of blood sugar control (glycaemic control) and faster disease progression.

But we don’t yet fully understand the cause of exercise intolerance and poor glycaemic control in these patients.


Dr Parker and his team have found evidence to support the theory that impaired microvascular function in skeletal muscle, as opposed to cardiac dysfunction, is the main underlying cause behind exercise intolerance and poor glycaemic control in many diabetic patients.

Dr Parker is also examining whether a three month home-based exercise program can improve muscle microvascular function, glycaemic control and exercise tolerance in patients with type 2 diabetes.

“Physical activity is well known to be an effective strategy for the treatment and management of type 2 diabetes, but many patients are unable to exercise, or they find exercise uncomfortable,” Dr Parker explained.

Next steps

Dr Parker will use modern biochemical and ultrasound imaging techniques to measure microvascular function, cardiac function, and glucoregulatory responses following ingestion of a standard meal and high-intensity exercise, in both exercise tolerant and intolerant diabetes patients.

“We will then explore whether exercise training can reverse potential structural and functional microvascular defects, and subsequently improve glycaemic control, exercise tolerance and overall quality of life in diabetes patients,” he said.

“We hope to improve our understanding of the mechanisms behind diabetes and highlight that microvascular health is just as important as cardiac health. This will allow us to develop new therapeutic interventions to improve patient care and quality of life,” Dr Parker said.

In Australia, more than 1 million people have been diagnosed with type 2 diabetes. It is estimated that a further 1 million cases exist undiagnosed and over 2 million people are at high risk of developing diabetes.