Insulin resistance and essential hypertension: mechanisms and clinical implications

The epidemiologic links among essential hypertension, obesity, and noninsulin-dependent diabetes mellitus (NIDDM) are well recognized, and it has been proposed that these links may reflect an underlying common pathophysiologic link of resistance to the action of insulin (insulin resistance). In essential hypertension, data suggest the insulin resistance pertains predominantly to nonoxidative glucose disposal, especially in skeletal muscle and adipose tissue, which contrasts with a more generalized deficit in obesity and NIDDM. A number of animal studies of genetic hypertension have confirmed the presence of insulin resistance, whereas acquired models of animal hypertension have not. The clinical significance of insulin resistance on long-term morbidity in hypertension remains unclear; there is limited evidence that insulin resistance may be an independent risk factor for subsequent vascular events, but it is more likely that it clusters with other better defined risk factors for the vascular complications of hypertension. The potential clinical sequelae of insulin resistance and hyperinsulinemia and the effect of antihypertensive medication on insulin resistance in general are addressed.