抄録
This article first deals with the definition and measurement of insulin resistance, and makes a distinction between primary and secondary insulin resistance. The closest proxy of insulin action, i.e., plasma insulin concentration, is then discussed together with its relationship with insulin action. The available epidemiological evidence, both from cross-sectional and longitudinal studies, is rather consistent in indicating an association between insulin levels and hypertension independent of obesity, glucose intolerance, and aging. A weak association between insulin levels and blood pressure has been found, in some series, even in normotensive, healthy individuals. However, there are marked interethnic differences in this association. So far, case-control studies have univocally confirmed the presence of insulin resistance in hypertensive patients as a group; pathophysiological experiments have shown that the skeletal muscle is an important site of such insulin sensitivity. Furthermore, it is clear that the insulin resistance of essential hypertension is selective for glucose metabolism, other actions of insulin being unaffected. The possible pathogenic significance of insulin resistance in essential hypertension is then discussed by focusing on the interactions between insulin and hemoynamics, particularly in skeletal muscle tissue. Finally, the fact that insulin resistance tends to cluster with abnormalities of blood pressure regulation, glucose tolerance and lipid metabolism is discussed in the context of atherosclerotic cardiovascular diseases. The cluster itself, and, possibly, hyperinsulinemia/insulin resistance, are potentially atherogenic; the clinical and therapeutic implications of this synergism are evident. (Hypertens Res 1992; 15: 67-75)
