Insulin Resistance Syndrome in Preeclampsia

Because changes in lipids, lipoprotein, and other metabolic processes, such as hyperinsulinemia and hyperuricemia, found in preeclampsia resemble the main features of the insulin resistance syndrome, it has been proposed that insulin resistance may be the common denominator for such metabolic changes. Several groups, using euglycemic-hyperinsulinemic clamping or intravenous glucose tolerance tests (Bergman's minimal model technique), have demonstrated insulin resistance during late pregnancy. Women with preeclampsia had higher fasting insulin levels, but also exaggerated hyperinsulinemia, in response to an oral glucose tolerance test, which is consistent with increased insulin resistance in preeclampsia. No direct measurement of insulin sensitivity (clamp or minimal model) has as yet been performed during preeclampsia. Increased insulin resistance can activate the sympathetic nervous system and lead to an increase in expression of receptors for endothelin, both of which events lead to increased blood pressure. Hyperinsulinemia can also induce hypertriglyceridemia, leading to endothelial dysfunction and reduction of prostacyclin production. This hyperinsulinemia can persist for as long as 17 years after preeclamptic pregnancy and may contribute to a woman's increased risk of cardiovascular disease. Insulin resistance may not be the cause of preeclampsia, but is one of the pathogenic factors, especially in genetically predisposed women.