Silva A Arslanian
Type 2 diabetes mellitus is a complex metabolic disorder of heterogeneous etiology, with social, behavioral, and environmental risk factors unmasking the underlying genetic susceptibility of individuals. 1 Insulin resistance and impaired insulin secretion are the two pathophysiological abnormalities responsible for type 2 diabetes. There is clearly a strong hereditary component to the disease, which is likely to be multigenic in nature. 2 The important role of genetic determinants is well illustrated when differences in the prevalence of type 2 diabetes in various racial/ethnic groups are considered. 3 However, even though genetic susceptibility to type 2 diabetes is important, the escalating prevalence of type 2 diabetes in youth is occurring too quickly to be the result of increased gene frequency and altered genetic pool. Environmental lifestyle factors play an important role. This chapter will review insulin sensitivity and secretion in childhood and discuss the factors responsible for abnormalities in either parameter that may lead to the expression of type 2 diabetes.