Yuka Kohda, Takao Tanaka and Hitoshi Matsumura
Once diagnosed with diabetes mellitus, the risk of diseases, such as nephropathy, neuropathy, retinopathy and heart disease also increases. The complication of diabetes accompanying myocardial disorder is known as diabetic cardiomyopathy, which is characterized by ventricular dilation that is usually asymptomatic as diabetes progresses. Myocardial fibrosis is closely related to diastolic dysfunction. Thiamine (vitamin B1), an essential micronutrient, has been reported to attenuate diabetic complications and all diabetics may be lacking in thiamine. Thiamine is a coenzyme utilized at multiple steps of glucose metabolism. We believe that thiamine repletion under hyperglycemia might activate glucose oxidation and reduce the overflow of glucose to the hexosamine biosynthesis pathway of glucose metabolism with concomitant reduction of diabetic lesions. The aim of this article is to highlight the role of thiamine, an important factor that combats diabetic complications, especially diabetic cardiomyopathy and also elucidate its impact on O-glycosylated protein in diabetes. Finally, we discuss the ability of thiamine repletion to prevent metabolic syndrome and obesity, which are considered prediabetic states, as well as prediabetic cardiomyopathy.