Early Subclinical Left-Ventricular Dysfunction in Obese Nonhypertensive Children: A Tissue Doppler Imaging Study
OBJECTIVES This study was designed to evaluate left ventricular (LV) diastolic functions and myocardial performance index (MPI) in obese individuals with or without metabolic syndrome (MetS). STUDY DESIGN The study included 44 obese subjects with MetS (16 men; 28 women; mean age 46±7 years) and 32 obese subjects without MetS (16 men, 16 women; mean age 43±9 years). Diagnosis of MetS was based on the ATP III criteria. Obesity was defined with a body mass index (BMI) of ≥30 kg/m2. All the subjects underwent echocardiography and tissue Doppler imaging to determine LV diastolic functions and MPI. Clinical and echocardiographic characteristics of obese subjects were compared with those of a control group consisting of 21 healthy, nonobese individuals (10 men, 11 women; mean age 42±4 years). RESULTS Waist circumference, weight, and BMI were similar in the two obese groups. Control subjects and obese subjects without MetS had similar systolic and diastolic blood pressures, fasting blood glucose, triglyceride, and HDL cholesterol levels, but all these significantly differed in patients with MetS. Left ventricular mass, mass index, and diastolic parameters were similar in the two obese groups, but differed significantly from the controls (p<0.05). Body mass index was correlated with the LV mass (r=0.42, p=0.001) and mass index (r=0.33, p=0.001). Left ventricular MPI was similar in the two obese groups with (0.59±0.10) and without (0.59±0.11) MetS, but was higher compared to the control group (0.48±0.06, p<0.05). Left ventricular MPI was correlated with BMI, waist circumference, LV mass, and mass index (r=0.24, p=0.02; r=0.30, p=0.005; r=0.31, p=0.002; r=0.21, p=0.04, respectively). CONCLUSION Our findings demonstrate that obesity with or without MetS affects LV MPI. In addition, LV MPI showed significant correlations with BMI, waist circumference, and LV mass.