In summary, the pathogenesis of Type 2 diabetes involves the
inheritance of diabetes susceptibility genes. The risk of
developing the disease is first manifested by insulin
resistance. Insulin resistance is worsened by a number of
factors including obesity and physical inactivity. If
insulin resistance is severe enough, IGT will appear.
When IGT is present, the risk of progressing to Type 2
diabetes is very high in all populations. A major factor
in determining progression from IGT to diabetes is the
inability of the beta-cell to secrete enough insulin to
compensate sufficiently for the level of insulin
resistance. Its capacity and ability to do so is further
decreased by persistent and increasing glycemia.