Search

To determine the associations of adiposity and insulin resistance with measures of vascular structure and function in children.A cross-sectional study included 252 children (age 15.1 ± 2.4 years; body mass index percentile 68.2 ± 26.5%; Tanner 2-5). Measurements of body fat percentage were obtained with dual-energy X-ray absorptiometry and visceral adipose tissue (VAT) with computed tomography. Insulin resistance was measured with hyperinsulinemic euglycemic clamp. Vascular measurements for endothelial function (brachial artery flow-mediated dilation [FMD]), vascular structure (carotid intima-media thickness [cIMT]), vascular stiffness (carotid incremental elastic modulus), and pulse wave velocity were analyzed by tertiles of adiposity and insulin resistance. Additional analyses with ANCOVA and linear regression were adjusted for Tanner, sex, race, and family relationship; FMD was also adjusted for baseline artery diameter.FMD was positively associated with high adiposity (body mass index, body fat percentage, and VAT) (P.01 all). Insulin resistance was not associated with FMD. cIMT was significantly, positively related to obesity, VAT, and insulin resistance (P.05 all). No differences in carotid incremental elastic modulus and pulse wave velocity were observed in relation to adiposity or insulin resistance.The findings suggest that adiposity is associated with higher FMD, and insulin resistance and VAT are associated with higher cIMT in children. Further research is needed to clarify the progression of these relations.

To compare markers of cardiovascular health in youth diagnosed with attention deficit hyperactivity disorder (ADHD) by the use of stimulant medication with healthy controls.Children and adolescents (n = 85; mean age 11.2 ± 2.8 years; 66 boys) diagnosed with ADHD using a stimulant and 53 siblings without ADHD (mean age 11.1 ± 3.8 years; 28 boys) were included in this cross-sectional study. Measured variables included blood pressure, heart rate (HR), HR variability: SD of the RR interval and low frequency to high frequency ratio, carotid-radial pulse wave velocity, carotid artery augmentation index (AIx), radial artery AIx, brachial artery flow-mediated dilation, and digital reactive hyperemic index.Compared with control patients, participants with ADHD had greater resting systolic blood pressure (3.9 mm Hg, 95% CI [1.2-6.7], P = .005), diastolic blood pressure (5.5 mm Hg, 95% CI [3.2-7.8], P .001), HR (9.2 beats/min, 95% CI [6.0-12.3], P .001), low frequency to high frequency ratio (0.55, 95% CI [0.22-0.89], P = .001), carotid AIx (7.2%, 95% CI [1.9-12.5], P = .008), and pulse wave velocity (0.36 m/s, 95% CI [-0.05, 0.78], P = .089), and lower SD of the RR interval (-33.7 milliseconds, 95% CI [-46.1, -21.3], P .001). Neither flow-mediated dilation nor reactive hyperemic index was significantly different.Children and adolescents being treated with a stimulant medication for ADHD exhibited signs of altered cardiac autonomic function, characterized by increased sympathetic tone, and showed evidence of arterial stiffening.

We sought to determine whether childhood wrist circumference predicts insulin resistance in adulthood. Measures were taken in prepubertal children and then approximately 30 years later in the same subjects as adults. Our findings suggest that wrist circumference in childhood is not a predictor of insulin resistance in adulthood.

To assess subclinical inflammation, fasting insulin, and endothelial function before and after exercise in overweight children and adolescents.Twenty-five children (body mass index [BMI]85th percentile) were assessed for brachial artery flow-mediated dilation (FMD), nitroglycerin-induced dilation, C-reactive protein (CRP), lipids, glucose, insulin, oral glucose tolerance, body composition, aerobic fitness (peak oxygen uptake [VO 2 peak]), and blood pressure. Twenty of these persons were equally and randomly assigned to either 8 weeks of stationary cycling or to a non-exercising control group.A baseline correlation was found between CRP and fasting insulin (r = 0.62; P.001), which remained significant after adjusting for baseline variables (r = 0.53; P.05). After 8 weeks, significant improvements were observed in the exercise group compared with the control group for VO 2 peak (exercise group = 21.8 +/- 2.1 to 23.2 +/- 1.5 mL/kg/minute vs control group = 23.4 +/- 1.6 to 20.9 +/- 2.2 mL/kg/minute; P.05), high-density lipoprotein (HDL) cholesterol (exercise group = 1.02 +/- 0.03 to 1.10 +/- 0.04 mmol/L vs control group = 1.08 +/- 0.07 to 0.99 +/- 0.09 mmol/L; P.05), and FMD area under the curve (AUC) (exercise group = 746 +/- 66 to 919 +/- 94 %*sec vs control group = 731 +/- 102 to 515 +/- 73 %*sec; P.05).In overweight children and adolescents, CRP is independently associated with fasting insulin. Eight weeks of aerobic exercise improves fitness, HDL cholesterol, and endothelial function in this group.