Background: the metabolic syndrome (MetS), an important contributor of insulin resistance and cardiovascular risk, is defined by three or more of the following clinical characteristics: abdominal obesity, hyperglycemia, hypertension, hypertriglyceridemia and hypo-HDL-cholesterolemia.

Aim: to review the existing data regarding the effect of Mets on peripheral and central blood pressure, stiffness and wave reflections.

Results: Increased aortic stiffness, a major mechanical factor predicting cardiovascular risk, is identified as participating to MetS. Its age-progression rate is proportional to the number of risk factors involved in MetS. Aortic stiffening with age is partly responsible for increased systolic blood pressure (SBP) and decreased diastolic blood pressure (DBP), the dominant hypertension phenotype in the elderly, which favors cardiac hypertrophy and coronary ischemia. Both parameters participate in the definition of pulse pressure (PP= SBP-DBP), which is of major importance in prognosis of subjects with MetS. Of note, beyond that of peripheral brachial parameters, central hemodynamic parameters associate to increased arterial stiffness reduced wave reflections and increased PP amplification, mainly attributed to enhanced heart rate. The latter findings are in the opposite direction than the one observed in essential hypertension in the absence of insulin resistance.

Conclusion: A diverging behavior of wave reflections and pulse pressure amplification, but not of arterial stiffness, is observed between hypertension alone and MetS. This might explain epidemiological findings on the reduced predictive value of MetS in the elderly and justify long term longitudinal studies relating central hemodynamics and mortality.