Objective-We characterized the state of the vascular endothelium in pediatric obesity by comparing circulating endothelial cell (CEC) number and activation phenotype in severely obese children to normal weight, overweight, and obese children.Study design-We used immunohistochemical examination of buffy-coat smears to enumerate CEC and immunofluorescence microscopy to quantify activated CEC in 107 children and adolescents. Normal weight (body mass index [BMI] <85 th percentile; N=40), overweight (BMI 85 th -<95 th percentile; N=17), and obese (BMI 95 th -<99 th percentile; N=23) participants were recruited from a longitudinal study. Severely obese (BMI ≥99 th percentile; N=27) participants were recruited from a pediatric obesity clinic. Group means (adiposity; systolic blood pressure [SBP] quartiles) were compared with general linear models, adjusted for sex, age, and race. Pearson correlations characterized relations of CEC with cardiovascular risk factors.Results-Activated CEC increased across BMI groups (p<0.002) and SBP quartiles (p<0.05). CEC number and activated CEC were highest in the severely obese group. CEC number was significantly associated with SBP, diastolic blood pressure, and triglycerides. Activated CEC were significantly associated with SBP and HDL-cholesterol.Conclusions-The vascular endothelium was activated in relation to excess adiposity, particularly in the severely obese, and to elevated SBP in children and adolescents.
KeywordsVascular Endothelium; Obesity; Children; Adolescents One of the fastest growing obesity categories in children is severe obesity, defined as an ageand sex-specific body mass index (BMI) ≥ 99 th percentile. Recent data indicate a 300% increase © 2010 Mosby, Inc. All rights reserved. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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MethodsThis cross-sectional study included 107 children and adolescents (age = 13.1 ± 3.8, range 6-22 years; 68 males) who were categorized (following testing) into four adiposity groups based on age-and sex-specific BMI percentiles. Participants in the normal weight BMI < 85 th percentile; N = 40), overweight (BMI 85 th -<95 th percentile; N = 17), and obese (BMI 95 th -<99 th percentile; N = 23) groups were consecutively enrolled over a period of approximately one year from a longitudinal cohort study investigating the early development of obesity, insulin resistance, and other cardiovascular risk factors. The severely obese (BMI ≥ 99 th percentile; N = 27) group was comprised of children and adolescents initially entering the University of Minnesota Pediatri...