Glucose Homeostasis and the Metabolic Syndrome

Glucose Homeostasis and the Metabolic Syndrome Glucose homeostasis represents the outcome of a complex feedback system for maintaining glucose tolerance within rather narrow physiological limits. Aberrant glucose homeostasis contributes to a number of downstream effects, including insulin resistance. Insulin resistance occurs when muscle, fat, or liver does not appropriately use the insulin that is produced by the pancreas. As a result, more insulin is required to process the same amount of glucose, but with increasing insulin resistance, there are increasing levels of glucose in the circulation. Deviant glucose homeostasis, coupled with insulin resistance, results in both hyperglycemia and hyperinsulinemia, leading to risk of type 2 diabetes mellitus (T2DM). T2DM, obesity, and other factors that increase the risk of cardiovascular disease constitute an entity defined as the metabolic syndrome. Although multiple (but similar) versions of the metabolic syndrome have been described (ie, insulin resistance syndrome, Syndrome X), they all include measures of obesity, hypertension, T2DM, and dyslipidemia. Importantly, genetic factors play a critical role in glucose homeostasis (T2DM), insulin resistance, and the components of the metabolic syndrome. This article accompanies the ATVB in Focus: Metabolic Syndrome and Insulin Resistance: Mechanisms and Consequences series that was published in the August 2012 issue.