Insulin Sensitivity and Blood Pressure
Jay S. Skyler Jennifer B. Marks Novelette E. Thompson Michael D. Fili Neil Schneiderman University of Miami
Hypertension, glucose intolerance, obesity, and hyperlipidemia are extremely prevalent problems in Western society, and each confers increased risk for coronary heart disease (CHD; Donahue, Skyler, Schneiderman, & Prineas, 1990). This cluster of disorders is so commonly associated as to suggest common pathogenetic mechanisms. Hyperinsulinemia and insulin resistance have been proposed to be the underlying link between these disorders ( Christlieb, Krolewski, Warram, & Soeldner, 1985; Donahue et al., 1990; Ferrari & Weidmann, 1990; Krieger & Landsberg, 1988; Reaven & Hoffman, 1987; Sims, 1982; Swislocki, 1990), which collectively have been dubbed the GOH (glucose intolerance-obesity-hypertension) syndrome by Modan et al. ( 1985), "Syndrome X" by Reaven ( 1988), the "deadly quartet" by Kaplan ( 1989), the "chronic disease risk factor syndrome" by Zimmet ( 1989), and the "insulin resistance syndrome" by DeFronzo and Ferrannini ( 1990).
It is well established that hyperinsulinemia and insulin resistance are characteristic features both of obesity and of glucose intolerance (both impaired glucose tolerance [IGT] and Type II diabetes mellitus; DeFronzo, 1988; Olefsky, 1981; Reaven, 1988). More recently, evidence has been developed relating hyperinsulinemia and decreased insulin sensitivity (i.e., insulin resistance) to elevated blood pressure. Before reviewing the evidence, it is helpful to review the methodology that has been used.
A variety of methods have been developed to quantify tissue sensitivity to insulin. Insensitivity to insulin, or insulin resistance, may be defined as