IGT

  • Condition in between normal and diabetes.
  • Blood glucose levels that are higher than normal, but below the level of a person with diabetes.
  • IGT is a combination of:
    • Impaired secretion of insulin
    • Reduce insulin sensitivity (insulin resistance)
  • IGT carries a high risk of progressing to type 2 diabetes, leading to it being referred to as ‘pre-diabetes’.
  • IGT is often associated with a cluster of inter-related cardiovascular risk factors known as the Metabolic Syndrome, Insulin Resistance Syndrome or Syndrome X. These are:
    • High blood pressure (hypertension)
    • High LDL-cholesterol (also called "bad" cholesterol)
    • Low HDL-cholesterol (also called "good" cholesterol)

Diagnosis

Blood Test Normal IFG IGT DM
FPG <6.1 mmol/l 6.1- <7 mmol/l <7 mmol/l ≥ 7.0 mmol/l
2hr PG <7.8 mmol/l X 7.8- <11.1 mmol/l ≥ 11.1 mmol/l

Some people who develop IGT will revert to normal glucose tolerance. Others will remain in a state of IGT. However, once IGT has developed, the body’s insulin secretion and sensitivity tend to continue to decline, ultimately resulting in type 2 diabetes.

Facts on IGT

  • About 40-50% of people with IGT will develop type 2 diabetes (accompanied by increased risk of cardiovascular disease and microvascular complications) within ten years.
  • Progressing to type 2 diabetes is not inevitable, and approximately 30% of individuals with IGT will return to normal glucose tolerance.
  • Cardiovascular complications associated with type 2 diabetes (e.g. increased atherosclerosis) begin to develop well before type 2 diabetes is diagnosed. By that time, macrovascular damage may already be well advanced.
  • In 2007 it was estimated that 309 million people had IGT. By 2025, the number of people with IGT is projected to increase to 419 million.
  • The South-East Asia Region currently has the highest number of people with IGT (93 million) and the highest prevalence rate (13.2% of the adult population).
  • By 2025 it is estimated that the South-East Asian Region will continue to have the highest prevalence rate with 13.5%, followed by the European Region with 10.9%.