From the Guidelines
Diabetes mellitus can be classified into four main categories: Type 1 diabetes, Type 2 diabetes, Specific types of diabetes due to other causes, and Gestational diabetes mellitus. According to the most recent and highest quality study 1, these categories are defined as follows:
- Type 1 diabetes: due to autoimmune b-cell destruction, usually leading to absolute insulin deficiency, including latent autoimmune diabetes of adulthood
- Type 2 diabetes: due to a progressive loss of adequate b-cell insulin secretion frequently on the background of insulin resistance
- Specific types of diabetes: due to other causes, e.g., monogenic diabetes syndromes, diseases of the exocrine pancreas, and drug- or chemical-induced diabetes
- Gestational diabetes mellitus: diabetes diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation
The classification of diabetes is important for determining therapy, but some individuals cannot be clearly classified as having type 1 or type 2 diabetes at the time of diagnosis 1. The traditional paradigms of type 2 diabetes occurring only in adults and type 1 diabetes only in children are no longer accurate, as both diseases occur in both age-groups 1.
Key points to consider in the management of diabetes include:
- Early diagnosis and appropriate management are essential for all types to prevent complications like cardiovascular disease, neuropathy, nephropathy, and retinopathy
- Lifestyle modifications and oral medications like metformin may be used to manage type 2 diabetes
- Insulin therapy is typically required for type 1 diabetes and may be necessary for type 2 diabetes in some cases
- Gestational diabetes usually resolves after delivery but increases future diabetes risk
It is essential to note that the classification and diagnosis of diabetes are not comprehensive and may vary depending on the individual case 1. Therefore, a thorough evaluation and diagnosis by a healthcare professional are necessary to determine the best course of treatment for each patient.
From the Research
Classification of Diabetes Mellitus
The classification of diabetes mellitus is based on its origin and clinical characteristics. The main types of diabetes mellitus are:
- Type 1 diabetes (T1D), an autoimmune disease 2
- Type 2 diabetes (T2D), commonly associated with lifestyle patterns, but not limited to them 2
- Gestational diabetes mellitus (GDM), resulting from a combination of genetic predisposition and pregnancy factors 2, 3
- Maturity Onset Diabetes of the Young (MODY) 4, 5
- Secondary diabetes, resulting from other medical conditions or treatments 4, 5
Characteristics of Each Type
Each type of diabetes has distinct characteristics:
- Type 1 diabetes: autoimmune destruction of beta-cells, requiring insulin for survival 2, 5
- Type 2 diabetes: varying degrees of insulin resistance and insulin hyposecretion 5
- Gestational diabetes mellitus: glucose intolerance with onset or first recognition during pregnancy, resulting from inadequate beta-cell compensation for insulin resistance 3
- MODY: a form of diabetes caused by genetic mutations, typically presenting at a young age 4, 5
- Secondary diabetes: resulting from other medical conditions, such as pancreatic disease or certain medications 4, 5
Diagnostic Criteria
The diagnostic criteria for diabetes mellitus have been established by various organizations, including the World Health Organization (WHO) and the American Diabetes Association: