The Types of Diabetes Mellitus

These are forms of type 1 diabetes with unknown aetiologies. Some patients may have permanent insulinopenia and are prone to ketoacidosis. This form of diabetes is inherited and has no immunological evidence for β-cell autoimmunity

2.1.1.2 Type 2 DM or non-insulin-dependent diabetes mellitus, is the most common (Manohar et al., 2002) and much more prevalent type accounting for 90%–95% of the cases in which the body does not produce enough insulin or properly use it (Li et al., 2004). It is a heterogeneous disorder characterized by insulin resistance coupled with impaired insulin secretion by β-cells in the pancreas (Kahn, 2008). It is caused by a combination of resistance to insulin action and an inadequate compensatory insulin secretory response (WHO, 2013).

2.1.1.3 Gestational diabetes mellitus (GDM)

Gestational diabetes occurs when pregnant females without a previous history of diabetes develop high blood-sugar levels (WHO, 2013). GDM is defined as any degree of glucose intolerance with onset during pregnancy.

Gestational diabetes mellitus (GDM) resembles type 2 DM in several respects, involving a combination of relatively inadequate insulin secretion and responsiveness. It occurs in about 2–10% of all pregnancies and may improve or disappear after delivery (NDIC, 2011). However, after pregnancy approximately 5–10% of females with gestational diabetes are found to have diabetes mellitus, most commonly type 2 later in life (NDIC, 2011).

2.1.1.4 Other specific types of diabetes

Impaired glucose tolerance (IGT) and Impaired fasting glucose (IFG)

The Expert Committee (ECDCDM, 2003) recognized an intermediate group of subjects whose glucose levels, although not meeting criteria for diabetes, are too high to be considered normal. IFG and IGT are associated with the metabolic syndrome, which includes obesity (especially abdominal or visceral obesity), dyslipidemia of the high-triglyceride and/or low-HDL type, and hypertension

Metabolic syndrome (also referred to as syndrome X)

This is a set of abnormalities in which insulin-resistant diabetes (type 2 diabetes) is almost always present along with hypertension (high blood pressure), high fat levels in the blood (increased serum lipids, predominant elevation of LDL cholesterol, decreased HDL cholesterol, and elevated triglycerides), central obesity, and abnormalities in blood clotting and inflammatory responses. Increased rate of cardiovascular disease is associated with metabolic syndrome.

Prediabetes

This indicates a condition that occurs when a patient’s blood glucose level is higher than normal but not high enough for a diagnosis of type 2 DM. Patients with IFG (Impaired fasting glucose) and/or IGT (Impaired glucose tolerance) are now referred to as having “pre-diabetes” indicating the relatively high risk for development of diabetes in these patients. Prediabetes increases the risk of developing type 2 diabetes, heart disease or stroke. Prediabetes can typically be reversed (without insulin or medication) by lifestyle changes, such as losing a modest amount of weight and increasing physical activity levels. Weight loss can prevent, or at least delay the onset of type 2 diabetes.