Plasma insulin, plasminogen activator inhibitor, and ankle-brachial systolic blood pressure ratio in overweight hypertensive subjects

Abstract

In hypertensive subjects, the ratio between ankle and brachial systolic blood pressure (ABI) has been shown to be an independent risk factor for cardiovascular diseases, particularly in the elderly. Plasma insulin may be an important interconnecting factor explaining this observation. In a population of middle-aged subjects with essential hypertension and moderate overweight, we identified whether the decrease in the ABI ratio was associated with the clinical and biochemical factors involved in resistance to insulin. Patients with diabetes and/or arteriosclerosis obliterans of the lower limbs were excluded from the population. Subjects were or were not on antihypertensive therapy. On the basis of univariate correlations, the ABI ratio was found to be significantly and negatively associated not only with the degree of abdominal fat distribution, but also with the usual biological features of resistance to insulin: plasma triglycerides and cholesterol; plasma glucose and insulin; and plasminogen activator inhibitor (PAI) antigen. In a multivariate analysis in subjects with untreated hypertension, the ABI ratio was significantly and negatively associated with only three variables: age, plasma insulin and PAI antigen. In treated hypertensive subjects, only the role of age and insulin remained significant. Since the alterations of the ABI ratio may be considered as a marker of the changes in the structure and function of arteries of the lower limbs, the study provides evidence that plasma insulin and PAI antigen, independently of the presence of significant atherosclerotic occlusive lesions, are susceptible to alter the pressure wave transmission in conduit arteries of the lower limbs.