Impact of the metabolic syndrome on aortic pulse pressure and ascending aortic pulsatility in patients with angiographically normal coronary arteries ascendante des coronaires normales la

T he metabolic syndrome, a cluster of atherosclerotic risk factors including impaired glucose tolerance, systemic hypertension, dyslipidemia and abdominal obesity (1,2), significantly increases the future cardiovascular risk of patients (3). Arterial stiffness is also recognized as an independent predictor of adverse cardiovascular outcomes (4,5). In fact, ascending aortic pulsatility (AP), an index of arterial stiffness, is related to the presence and extent of coronary artery disease and also has been shown to be a powerful predictor of restenosis after percutaneous transluminal coronary angioplasty (6,7). Increased arterial stiffness has been demonstrated in obese children with the metabolic syndrome (8). Furthermore, central arterial stiffness and insulin resistance have been positively corre-lated (9,10). Moreover, the extent of metabolic changes has been shown to predict arterial stiffness in a dose-dependent manner (11). Impaired glucose tolerance and hyperinsulinemia promote wall hypertrophy and fibrosis by increasing the local activity of the renin-angiotensin-aldosterone system (12-14). Impaired glucose tolerance also increases nonenzymatic glycation of proteins and alters the structure of the arterial wall (15). the association of the metabolic syndrome, as a whole, with large artery stiffness (11,18,19). In the present study, we evaluated the impact of the metabolic syndrome on two determinants of large artery stiffness – aortic pulse pressure (PP) and ascending AP – in patients with angiographically normal coronary arteries. Impact of the metabolic syndrome on aortic pulse pressure and ascending aortic pulsatility in patients with angiographically normal coronary arteries. BACKGROUND: Large artery stiffness is a major determinant of pulse pressure (PP), and PP at baseline has been associated with future coronary events. OBJECTIVE: To evaluate the impact of the metabolic syndrome on aortic PP and ascending aortic pulsatility (AP) in patients with angiographically normal coronary arteries. METHODS: Forty-two patients with the metabolic syndrome and 40 age- matched control subjects without the metabolic syndrome were included in the study. All subjects had normal coronary arteries. Diagnosis of the metabolic syndrome was based on the International Diabetes Federation guidelines published in 2005. Ascending AP was estimated as the ratio of aortic PP to mean blood pressure. RESULTS: Aortic PP (59±12 mmHg versus 43±10 mmHg; P<0.001) and ascending AP (0.54±0.10 versus 0.48±0.10; P<0.001) were significantly higher in the metabolic syndrome group. Multiple regression analysis revealed statistically independent relationships between ascending AP and fasting blood glucose, waist circumference and systolic blood pressure (model R 2 =0.408; P<0.001). The metabolic syndrome, as a whole, was also independently associated with both ascending AP (P<0.01) and aortic PP (P<0.01). CONCLUSION: The data showed that the metabolic syndrome is independently associated with increased aortic PP and ascending AP in patients with normal coronary arteries, suggesting aortic stiffness as one of the possible mechanisms underlying the excess cardiovascular risk associated with the metabolic syndrome.