General practice management of type 2 diabetes

1. Introduction
     Defining type 2 diabetes
☰ Table of contents

Diabetes is a group of disorders and the 10th leading cause of deaths in Australia. There are four clinical classes of diabetes:1

  • Type 1 diabetes – Results from ß-cell destruction due to an autoimmune process usually leading to insulin deficiency
  • Type 2 diabetes – Results from a progressive insulin secretory defect on the background of insulin resistance
  • Gestational diabetes mellitus (GDM) – Defined as glucose intolerance with onset or first recognition during pregnancy
  • Other specific types of diabetes (Section 3.3. Impaired fasting glucose or impaired glucose tolerance) – Due to other causes such as genetic defects in ß-cell function, genetic defects in insulin action, diseases of the exocrine pancreas (eg cystic fibrosis), and drug-induced or chemical-induced causes (eg treatment of human immunodeficiency virus/acquired immune deficiency syndrome [HIV/ AIDS] or after organ transplantation)

Type 2 diabetes is a largely preventable, chronic and progressive medical condition that results from two major metabolic dysfunctions: insulin resistance and then pancreatic islet cell dysfunction causing a relative insulin deficiency. In an individual, these occur due to modifiable lifestyle-related risk factors interacting with nonmodifiable and genetic risk factors.

The relative insulin deficiency leads to chronic hyperglycaemia and multiple disturbances in carbohydrate, protein and fat metabolism including:

  • ß-islet cell dysfunction, failure of response to insulin signalling and increased islet cell apoptosis
  • α-cell dysfunction with elevated glucagon levels
  • resultant disorders of hepatic gluconeogenesis and insulin resistance with elevated glucose production
  • muscle cell insulin resistance with decreased glucose uptake
  • kidney adaptation with altered gluconeogenesis and increased glucose reabsorption via increased sodium glucose transporter protein activity
  • diminished incretin hormonal production or resistance
  • maladaptive cerebral hormonal responses to insulin and appetite
  • increased lipolysis with elevated free fatty acids.

Diabetes Australian and RACGP logo's
  1. Shaw J, Tanamas S, editors. Diabetes: the silent pandemic and its impact on Australia. Melbourne: Baker IDI Heart and Diabetes Institute, 2012.