Does metabolic syndrome worsen systolic dysfunction in diabetes? The shortwave study

Patients with metabolic syndrome (MetS) have high cardiovascular event rates. The additional effect of MetS on left ventricular (LV) systolic function in patients with type 2 diabetes mellitus (T2DM) is unknown. We studied the relation between MetS and LV systolic function in T2DM patients without coronary artery disease (CAD). Clinical and echocardiographic data from 331 T2DM patients were analyzed. Prevalence of MetS was assessed based on NCEP ATPIII definition. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were analyzed as indexes of circumferential and longitudinal shortening, respectively. Sc-MS was impaired if <89 %, S' if <8.5 cm/s (10th percentile of healthy controls). MetS was diagnosed in 172 patients. Sc-MS and S' were similar in T2DM patients with and without MetS (91 ± 14 vs 92 ± 15 %; 9.8 ± 2.0 vs 9.5 ± 2.1 cm/s, respectively; p = ns) but significantly reduced comparing to controls (102 ± 11 % and 10.8 cm/s; p < 0.0001). Impairment of sc-MS and S' were detected in 37 vs 40 % and in 29 vs 32 % of T2DM patients with and without MetS (p = ns), respectively. LV systolic function measured as sc-MS and S' is frequently impaired in T2DM patients without CAD; however, the coexistence of MetS is not associated with more severe LV systolic dysfunction. Further pathological mechanisms have to be considered to explain the negative prognostic impact of MetS in T2DM patients.