Physiological damages directly or indirectly caused by diabetes have become one of the major risks for morbidity and mortality among patients worldwide. 1 Diabetic complications include diabetic cardiovascular diseases, 2 cerebrovascular diseases, kidney diseases, neuropathy, eye diseases and diabetic foot, among which diabetic heart insufficiency is the most deadly. 3 More than 70% of diabetic patients die of cardiovascular diseases, 2-4 times higher than non-diabetic patients. 4,5 The pathophysiological mechanisms of diabetic heart diseases are complicated and mainly include metabolic alterations in the substrate, microvascular dysfunction, renin-angiotensin-aldosterone system activation, oxidative stress, mitochondrial dysfunction, and damaged Ca 2+ transportation, which ultimately leads to coronary artery disease, cardiac failure or even sudden death. 6 Glucotoxicity caused by glucose overload is also the main cause of diabetic cardiac dysfunction. 7 Cardiomyocyte glucose overload caused by impaired glucose metabolism promotes oxidative stress and glycosylation, as well as the chronic activation of hexosamine and other pathways. 8 Cardiomyocyte apoptosis thus activates the mTOR signalling pathway and leads to endoplasmic reticulum (ER) stress, which ultimately causes diabetes-induced