Before anything, let's talk about what diabetes is and what it does to people The metabolic illness known as diabetes mellitus is caused by an inability of the body to produce or properly use insulin. It causes metabolic disruptions in carbohydrate, lipid, and protein synthesis, leading to persistent hyperglycemia (high plasma glucose levels). Diabetic retinopathy, nephropathy, and neuropathy are all chronic consequences of diabetes mellitus. There is a higher possibility of developing cardiovascular disease.