The pathophysiology of type 2 diabetes mellitus: an overview

Type 2 diabetes mellitus is a heterogeneous disorder characterized by chron ic hyperglycaemia. The aetiological heterogeneity is suggested by genetic i nheritance and its interplay with environmental factors. Impaired insulin s ecretion and decreased insulin sensitivity are the main pathophysiological features, responsible for development of hyperglycaemia in type 2 diabetes. However, the genetic basis of these defects has been demonstrated only in small subgroups of patients. Whether impaired secretion or action of insuli n is the primary defect in the majority of patients is not known, although it is generally agreed that defective insulin release is a requirement for the disease to develop.