Biophysical properties of the aorta and left ventricle and exercise capacity in obese children.

We sought to determine whether childhood obesity is associated with increased aortic stiffness by measuring the biophysical properties of the aorta in obese children using a noninvasive echocardiographic Doppler method. Increased aortic stiffness is a strong predictor of future cardiovascular events and mortality in adults. Obesity is known to be associated with increased aortic stiffness and arterial disease in adults. We prospectively evaluated a cohort of obese children (n = 61) and compared them to normal-weight controls (n = 55). The anthropometric data were recorded. The pulsewave velocity (PWV), aortic input impedance (Zi), characteristic impedance (Zc), arterial pressure-strain elastic modulus (Ep), arterial wall stiffness index (B index), and peak aortic velocity were calculated. We correlated our echocardiographic Doppler findings with the lipid levels. We assessed the left ventricular (LV) dimensions and standard measures of cardiac function. Cardiopulmonary exercise testing was performed on all obese children. Compared to normal-weight children, obese children had a greater PWV, Zc, B index, Ep, and peak aortic velocity. Obese children had greater systolic blood pressure than normal-weight children but no difference in diastolic blood pressure. The LV dimensions and standard measures of cardiac systolic function were similar in the 2 groups, but the obese children had altered diastolic properties. The LV mass was greater in the obese children. No association was found between the lipid levels and the biophysical properties of the aorta. The relative oxygen consumption was 68% predicted in obese children. In conclusion, measures of the biophysical properties of the aorta are already abnormal in obese children, reflecting increased aortic stiffness at this early stage of disease. Obese children also had an increased LV mass, altered diastolic properties, and an abnormal exercise capacity. PWV might be useful in monitoring the progression of arterial disease or the effect of therapeutic interventions.

The centre for healthy weights--shapedown BC: a family-centered, multidisciplinary program that reduces weight gain in obese children over the short-term.

The objective was to conduct a program evaluation of the Centre for Healthy Weights-Shapedown BC (CHW-SB), a family-centered, multidisciplinary program for obese children, by assessing the change in weight trajectories from program intake to completion. Secondary outcomes included changes in clinical, biochemical and psychological parameters, and in physical activity (PA) levels. The CHW-SB program was evaluated over 10 weeks. Data collection included anthropometric, metabolic, PA and psychological measures. Longitudinal mixed effects regression was performed to evaluate weight change from Phase 1 (before program on waitlist) to Phase 2 (during program). 238 children <18 years of age were referred to the program of which 119 were eligible for participation. There was a significant decrease in weight trajectory in children following program entry. Participants experienced an average .89% monthly increase before program entry, compared to a .37% monthly decline afterwards, a drop of 1.26% (p < 0.0001, 95%CI 1.08 to 1.44). zBMI (2.26 ± 0.33 to 2.20 ± 0.36, p < 0.001), waist circumference (99 ± 15.7 to 97 ± 16 cm, p < 0.0001) and fasting insulin (137 ± 94.8 to 121 ± 83.4 pmol/L, p < 0.001) also decreased in participants who attended the final visit. Significant improvements were seen in all measures of PA, self-concept, and anxiety. CHW-SB, a government-funded program, is the first obesity-treatment program to be evaluated in Canada. While short-term evaluation revealed significant improvements in adiposity, PA, and psychological measures, the lack of full follow-up is a limitation in interpreting the clinical effectiveness of this program, as drop-out may be associated with lack of success in meeting program goals. These data also emphasize the need for ongoing evaluation to assess the long-term implications of this unique program and ultimately optimize utilization of governmental resources.