Building Competency in Diabetes Education THE ESSENTIALS

PATHOPHYSIOLOGY| 3-13

PATHOPHYSIOLOGY OF DIABETES

Diabetes mellitus refers to a group of metabolic disorders characterized by hyperglycemia resulting from reduced insulin secretion, decreased glucose utilization and/or increased glucose production (5). There are two broad types of diabetes mellitus type 1 and type 2 diabetes based on the pathology that resulted in hyperglycemia, as opposed to previously used characteristics, such as age of onset or therapy (5). Other forms of diabetes that may share features of type 1 or type 2 diabetes are increasingly recognized and better understood.

Types of diabetes

Type 1 diabetes Type 1 diabetes primarily results from the destruction of beta cells leading to insulin deficiency, and can lead to ketoacidosis (1). There are two forms of type 1 diabetes:

1. Immune-Mediated Type 1 Diabetes The presence of islet cell cytoplasmic autoantibodies (ICA), glutamic acid decarboxylase (GAD) autoantibodies or insulin autoantibodies (IAA) can identify an autoimmune cause of the beta cell destruction (1,16). This is defined as immune-mediated diabetes. GAD autoantibodies become more common with increasing age of onset (17). This form of diabetes often occurs in childhood and adolescence, but it can be seen at any age even in the eight and ninth decades (16). Genetically, this condition has strong HLA association and predisposes individuals with this form of diabetes to other autoimmune disorders. 2. Idiopathic Type 1 Diabetes In many patients with type 1 diabetes, where the cause of beta cell destruction is unknown and evidence of autoimmunity is not present, the term “idiopathic” type 1 diabetes is used. The rate of beta cell destruction is quite variable, being rapid in some (mainly young people) and slow in others (mainly adults) and related to both genetic