best diabetic clinics near me Diabetic cardiomyopathy is caused by a combination of metabolic abnormalities and other complications of diabetes, including chronic hyperglycemia (high blood sugar), insulin resistance, oxidative stress, and inflammation. These factors contribute to cardiac lipotoxicity (fat accumulation and damage in heart cells), fibrosis (scarring of heart tissue), mitochondrial dysfunction, autonomic neuropathy, and impaired calcium handling, all of which can lead to heart muscle damage and dysfunction over time.