Differential impact of metabolic syndrome on arterial stiffness and wave reflections: focus on distinct definitions - Vyssoulis, Gregory P; Pietri, Panagiota G; Karpanou, Eva A; Vlachopoulos, Charalambos V; Kyvelou, Stella-Maria; Spanos, Panagiotis; Cokkinos, Dennis V; Stefanadis, Christodoulos I (International journal of cardiology, 2010)