Because the specific etiological mechanisms of diabetes mellitus are not well studied, the following types of diabetes mellitus are currently used internationally, using the typing criteria proposed by the WHO Expert Committee on Diabetes Mellitus (1999):
1. Type 1 diabetes mellitus (T1DM). It is also known as insulin-dependent diabetes mellitus, mostly in adolescents, with an acute onset and more severe symptoms. It mainly refers to the destruction of pancreatic islet B cells, which are responsible for insulin secretion, resulting in an absolute deficiency of insulin secretion and requiring long-term insulin for treatment.
2. Type 2 diabetes mellitus (T2DM). Insulin secretion is normal, but the body’s tissue utilization is impaired, i.e. insulin resistance, mostly seen in middle-aged people over 40 years old. The symptoms are milder than those of type 1 diabetes.
3. Specific types of diabetes, such as genetic defects in islet B-cell function (adult-onset diabetes in young adults), genetic defects in insulin action (leprechaunomorphic syndrome), exocrine diseases of the pancreas (pancreatitis, pancreatic tumors), endocrine diseases (acromegaly, Cushing’s syndrome, pancreatic hyperglycemia, pheochromocytoma, etc.), caused by drugs or chemicals diabetes, infections, ankylosing muscular dystrophy, etc.
4. Gestational diabetes mellitus. It is a condition in which the pregnant woman’s blood sugar exceeds normal values during pregnancy.