The Impact of Isolated Obesity on Right Ventricular Function in Young Adults

BACKGROUND Obesity is an independent risk factor for cardiovascular diseases. The effects of obesity on left ventricular structure and function have been reported, but relatively little is known regarding right ventricular (RV) function in obesity. OBJECTIVE To evaluate subclinical RV alterations in obese, but otherwise healthy, young adults by conventional echocardiography and tissue Doppler imaging (TDI). METHODS In this study, we included 35 normal weight healthy subjects with a body mass index (BMI) < 25 kg/m² (group I), 27 subjects with a BMI of 30-34.99 kg/m² (group II), and 42 subjects with a BMI > 35 kg/m² (group III). All subjects underwent transthoracic echocardiography. In addition to standard echocardiographic measurements, tricuspid annular peak systolic (Sm), peak early (Em), and late diastolic (Am) velocities, isovolumetric contraction (ICTm), relaxation (IRTm) time, and ejection time (ETm) were obtained by TDI, and RV myocardial performance index (MPIm) was calculated. RESULTS In group II, RV Em/Am was significantly decreased and IRTm and MPIm were significantly increased compared to group I (p < 0.01). RV Sm, Em, and the Em/Am ratio were significantly lower and RV IRTm and MPIm were significantly higher in group III than in group II (p < 0.05 for RV Sm and IRTm and p < 0.01 for others). RV Am differed significantly between groups III and I (p < 0.05). BMI was significantly and negatively correlated with RV Sm, Em, and the Em/Am ratio, but positively correlated with RV MPI (p < 0.01). CONCLUSION Our study showed that isolated obesity in young normotensive adults was associated with subclinical abnormalities in RV structure and function.