Dynamics of insulin secretion in obesity and diabetes

Insulin resistance and compensatory hyperinsulinemia are commonly present i n obesity. The biochemical mechanisms responsible for the maintenance of ba sal hypersecretion of insulin are reviewed in this article. Under basal, fa sting and fed conditions the hyperinsulinemia of obesity largely depends on increased insulin secretion, without any alteration of the temporal secret ion. This suggests that the functioning beta cell mass is enhanced, but nor mal regulatory mechanisms are maintained, A number of alterations in beta-c ell function are present in conditions of impaired glucose tolerance which precede the onset of overt diabetes.