Metabolic syndrome may be associated with increased arterial stiffness even in the absence of hypertension: a study in 84 cases and 82 controls

Abstract

Objective: To evaluate the hemodynamic characteristics of metabolic syndrome (MetS) in the absence and presence of hypertension.

Materials/methods: Altogether 166 subjects without previously diagnosed cardiovascular disease, diabetes, or antihypertensive medication, were allocated to four groups: control, hypertension only, MetS without hypertension, and MetS with hypertension (mean age 44-46 years). Cut-point for hypertension was blood pressure ≥140/90 mmHg. Other criteria of MetS were as defined by Alberti et al. 2009. Hemodynamic variables were measured using whole-body impedance cardiography and pulse wave analysis.

Results: Pulse wave velocity was higher in hypertensive and normotensive subjects with MetS than controls (p<0.05), and in the hypertensive MetS group than subjects with hypertension only (p<0.05). Aortic pulse pressure was higher in the two hypertensive groups than the two normotensive groups (p<0.05). Systemic vascular resistance index was higher in the hypertensive than normotensive MetS group (p<0.05), and in the group with hypertension alone than in controls (p<0.05). Heart rate was higher in the hypertensive Mets group than in controls and subjects with hypertension only (p<0.05). Cardiac index did not differ, while stroke index was lower in both groups with MetS than groups without MetS. Augmentation pressure was higher in the hypertensive MetS group than in controls and normotensive MetS group (p<0.05).

Conclusions: Pulse wave velocity, an acknowledged marker of arterial stiffness, was associated with MetS even in the absence of hypertension. This emphasizes the importance of the prevention and treatment of MetS.

Keywords: AGEs; AIx; ANOVA; Abdominal obesity; BMI; CI; HDL; HOMA-IR; HT; HT-MetS; Hemodynamics; LDL; MetS; NT-MetS; PWA; PWV; Pulse wave velocity; SE; SVRI; Triglycerides; augmentation index; body mass index; confidence interval; eGFR; estimated creatinine-based glomerulus filtration rate; glycation end-products; high-density lipoprotein; homeostasis model assessment of insulin resistance; hypertensive group; hypertensive metabolic syndrome group; low-density lipoprotein; metabolic syndrome; normotensive metabolic syndrome group; one-way analysis of variance; pulse wave analysis; pulse wave velocity; standard error of the mean; systemic vascular resistance index.