Metabolic syndrome and left ventricular function: Is the number of criteria actually important?

BACKGROUND: Metabolic syndrome (MS) is a clustering of cardiovascular risk factors responsible for the development of target organ damage. The aim of this study was to determine the effect of the increasing number of MS risk factors on left ventricular function assessed by noninvasive methods. MATERIAL/METHODS: The study included 204 subjects with MS and 76 controls with no MS risk factors. MS was defined by the presence of 3 or more of ATP-NCEP III criteria. MS subjects were grouped according to the number of criteria they fulfilled: 3 criteria (n=91), 4 criteria (n=65) and 5 criteria (n=48). All subjects underwent laboratory blood tests, complete 2-dimensional, pulse and tissue Doppler echocardiography. Echocardiography was used to assess systolic (LVEF, s(septal)), diastolic function, by pulse-wave Doppler (E/A ratio) and tissue Doppler imaging (E/e′(average)), and global left ventricular function (Tei index). Appropriate time intervals for the estimation of the Tei index were obtained by tissue Doppler. RESULTS: Transmitral E/A ratio decreased significantly and progressively from the 3 criteria to the 5 criteria group (0.82±0.25 vs. 0.79±0.24 vs. 0.67±0.14, p<0.001). The transmitral E/E′(average) ratio was significantly and gradually increased from the 3 criteria to the 5 criteria group (7.76±1.81 vs. 9.44±2.35 vs. 10.82±2.56, p<0.001). The left ventricle Tei index progressively increased from the 3 criteria to the 5 criteria group (0.43±0.11 vs. 0.48±0.10 vs. 0.54±0.12, p<0.001). CONCLUSIONS: The increasing number of MS criteria is associated with cardiac diastolic dysfunction.