Preclinical noninvasive markers of atherosclerosis in children and adolescents with type 1 diabetes are influenced by physical activity.

OBJECTIVES: To measure preclinical noninvasive markers of atherosclerosis in youth with type 1 diabetes (T1DM), and to determine their associations between physical activity level and cardiorespiratory fitness (maximal oxygen consumption [VO2max]). STUDY DESIGN: This was a cross-sectional study including 32 patients with T1DM and 42 healthy subjects aged 6 to 17 years. Main outcome measures included arterial flow-mediated dilation (FMD) and intima-media thickness with high-resolution ultrasonography; physical activity by accelerometer (valid 26 patients with T1DM, 35 healthy subjects) and VO2max. RESULTS: Compared with healthy control subjects, patients with T1DM had higher intima-media thickness (mean 0.50 mm [0.48-0.52, 95% CI] vs 0.48 [0.47-0.49], P=.02) and reduced FMD (4.9% [4.1%-5.7%] vs 7.3 [6.4-8.1], P=.001), VO2max (45.5 mL/kg/min [43.0-48.0] vs 48.7 [46.7-50.6], P

Association of arterial stiffness and endothelial dysfunction with metabolic syndrome in obese children.

OBJECTIVE: We investigated whether metabolic syndrome, defined in 3 different ways (2 commonly used and 1 novel) is associated with arterial alterations in obese children. STUDY DESIGN: The study group comprised 384 obese children age 2.5 to 18 years. Blood pressure, fasting blood glucose, blood insulin, plasma lipids, and body composition were measured. Noninvasive ultrasound measurements were obtained in 161 patients to investigate arterial mechanical properties and endothelial function. RESULTS: The prevalence of metabolic syndrome was 10.4%. Intima-media thickness correlated positively with low-density lipoprotein cholesterol (r = .21; P < .01) and negatively with high-density lipoprotein cholesterol (r = -.17; P < .05). In adolescents (11 to 18 years), cross-sectional vascular compliance correlated negatively with abdominal fat (r = -.22; P = .02). The only synergistic effects among individual metabolic syndrome components was an effect of insulinemia and systolic blood pressure on cross-sectional compliance (4.05; P < .05). No significant difference in vascular variables was found between the patients with and without metabolic syndrome using any of the 3 definitions. CONCLUSION: Metabolic syndrome in obese children is not related to arterial variables, whereas several of its individual components are associated with vascular alterations. These data suggest that the value of the metabolic syndrome as a predictor of future cardiovascular events in children remains to be prospectively evaluated. In the meantime, individual cardiovascular risk factors should be evaluated and controlled.

Associations among obesity, blood pressure, and left ventricular mass.

OBJECTIVES: To measure resting and ambulatory systemic blood pressure (BP) and left ventricular mass (LVM) in prepubertal obese and lean children and to determine their relationships. STUDY DESIGN: Cross-sectional study including 44 obese and 22 lean prepubertal children (mean age 8.8 +/- 1.5 years). We measured casual and 24-hour ambulatory BP, LVM and LVM index (LVMI) by echocardiography, and whole body lean tissue and fat mass by dual-energy X-ray absorptiometry. RESULTS: Mean 24-hour systolic BP (124.8 +/- 14.2 vs 105.5 +/- 8.8 mm Hg), diastolic BP (72.8 +/- 7.3 vs 62.7 +/- 3.8 mm Hg), and LVMI (36.1 +/- 5.8 vs 30.9 +/- 5.7, g x m(-2.7)) were significantly higher in obese than in lean subjects. Systolic ambulatory hypertension was present in 47.6% of obese children, and casual BP was normal in 55% of those cases. Body fatness, lean tissue mass, and 24-hour BP correlated positively with LVMI. When adjusted for body fatness, LVMI was only associated with 24-hour systolic BP (adjusted R(2) = 15.9%; P = .001). CONCLUSIONS: Ambulatory systemic hypertension and increased LVM are found in obese children. Left ventricular mass is partially determined by systemic BP. We conclude that prevention and treatment of childhood obesity should be initiated as early as possible to prevent the premature development of hypertension and end-stage organ damage.

Comparison of classifications for heart failure in children undergoing valvular surgery.

OBJECTIVES: To characterize correlations between clinical classifications of heart failure and diagnostic workup. STUDY DESIGN: Pre- and postoperative characteristics of 20 children with heart failure secondary to valvular rheumatic disease were studied. RESULTS: Both scoring systems correlated with N-terminal pro-brain natriuretic peptide (N-proBNP) but not with troponin I (TnI). The PHFI correlated with N-proBNP, end-systolic wall stress, left ventricular mass index and left atrium to aorta diameter ratio. No correlation could be established between modified Ross score, or the New York Heart Association (NYHA) grade and echocardiographic measurements. Cardiothoracic and Sokolow indexes were correlated with the PHFI as well as to the NYHA classification. CONCLUSION: In this study, PHFI seems better correlated with radiologic, electrocardiographic, echocardiographic, and biologic assessment of heart failure in children. Clinical severity was correlated with N-proBNP but not with TnI.