Increased levels of blood fats in people with type 2 diabetes and obesity are more harmful than previously thought, a new study from the University of Leeds has found. In patients with metabolic diseases, elevated fat levels in the blood create stress in muscle cells – a reaction to changes outside the cell – which damage their structure and function. The signals can kill the cells, make symptoms more severe, and worsen the illness. Increased fat in the blood has long been known to damage tissues and organs, contributing to the development of cardiovascular and metabolic diseases including type 2 diabetes. The condition can be caused by obesity. Although this research is at an early stage, the discovery may form the basis of new therapies to prevent the development of cardiovascular and metabolic diseases.