Right Ventricular Subclinical Diastolic Dysfunction in Obese Children: The Effect of Weight Reduction with a Low-Carbohydrate Diet

This study aimed primarily to identify whether childhood obesity leads to right ventricular (RV) subclinical diastolic dysfunction or not. It also aimed to examine the effect of weight reduction on right ventricular function. Standard and tissue Doppler echocardiography was performed for 28 overweight (body mass index [BMI], 25-30 kg/m(2)) and 34 obese (BMI, a parts per thousand yen30 kg/m(2)) children and for 29 age- and sex-matched lean referents (BMI, 17-25 kg/m(2)). Levels of plasma lipids, fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) were obtained for all the participants. For 6 months, 30 obese children were given a low-carbohydrate diet and then reevaluated by echocardiography. Conventional echocardiographic parameters all were similar for obese, overweight, and lean control children. The tricuspid free-wall isovolumetric relaxation time (IVRT), tricuspid lateral annular early diastolic velocity (e'), ratio of early-to-late diastolic velocity (e'/a'), and tricuspid lateral annular IVRT differed significantly between the overweight and control children. The RV tissue Doppler parameters were found to be similar between the preobese and control children. The IVRT of the RV free wall and lateral tricuspid annulus was significantly decreased, and the e'/a' of the lateral tricuspid annulus was significantly increased after the diet. In conclusion, obesity is associated with subclinical RV diastolic dysfunction in pediatric patients. Weight reduction with a low-carbohydrate diet may reverse the effects of obesity on RV diastolic function.