Hypertension and vascular dynamics in men and women with metabolic syndrome

Abstract

Metabolic syndrome (MetS), an important component of insulin resistance and cardiovascular (CV) risk, is defined by 3 or more of the following characteristics: abdominal obesity, hyperglycemia, hypertension, hypertriglyceridemia, and hypo-high-density lipoprotein cholesterolemia. Based on the previously published age- and sex-mediated DESIR (Data from an Epidemiological Study on the Insulin Resistance Syndrome) cohort and parallel central hemodynamic measurements, our goal was to evaluate the effects of MetS on brachial central pulse pressure (PP), PP amplification, aortic stiffness, and wave reflections. These data were then compared with those of patients with essential hypertension but without MetS for the same mean arterial pressure. Increased aortic stiffness, a major mechanical factor predicting CV risk, has been well identified as playing a role in MetS. Its age progression is proportional to the number of risk factors involved in MetS and is responsible for increased systolic blood pressure and decreased diastolic blood pressure with increasing age, the principal hallmarks of hypertension in the elderly. Beyond brachial pressure measurements, central hemodynamic parameters involve increased aortic stiffness, reduced wave reflections, and increased PP amplification, a parameter commonly associated with increased heart rate. With the exception of arterial stiffness, all these findings are opposite in direction to those observed in essential hypertension, in which MetS is absent. A divergent behavior of wave reflections and PP amplification, but not of arterial stiffness, is observed when hypertension is studied alone or when compared with MetS for the same mean arterial pressure. This pulsatile hemodynamic abnormality contributes independently to increase age- and sex-mediated CV risk, justifying new research regarding Framingham scores and drug treatment.