title: Oxidative stress and cardiovascular risk in overweight children in an exercise intervention program.
abstract: BACKGROUND
  This study aimed to determine whether oxidative stress was related to cardiovascular risk indices in children, and whether an exercise intervention would reduce oxidative stress.
  
  
  METHODS
  A randomized trial of two different doses of exercise and a no-exercise control group included 112 overweight and obese children, 7-11 years old. Plasma isoprostane levels were obtained at baseline and after the intervention. Cross-sectional analysis of oxidative stress and metabolic markers at baseline was performed. The effect of the exercise training on oxidative stress was tested.
  
  
  RESULTS
  Lower isoprostane levels were observed in blacks. At baseline, isoprostane was positively related to measures of fatness (BMI, waist circumference, percent body fat), insulin resistance and β-cell function (fasting insulin, insulin area under the curve, Matsuda index, disposition index, oral disposition index), and several lipid markers (low-density lipoprotein, triglycerides, total cholesterol), and inversely with fitness [peak oxygen consumption (VO(2))], independent of race, sex, and cohort. No relation was found with visceral fat, blood pressure, or glycemia. Independent of percent body fat, isoprostane predicted triglycerides, β=0.23, total cholesterol-to-high-density lipoprotein (TC/HDL) ratio, β=0.23, and insulin resistance (insulin area under the curve, β=0.24, Matsuda index, β=-0.21, oral disposition index, β=0.33). Exercise did not reduce oxidative stress levels, despite reduced fatness and improved fitness in these children.
  
  
  CONCLUSIONS
  Isoprostane levels were related to several markers of cardiovascular risk at baseline; however, despite reduced fatness and improved fitness, no effect of exercise was observed on isoprostane levels. To our knowledge, this is the first report in children to demonstrate a correlation of oxidative stress with disposition index, fitness, and TC/HDL ratio, the first to test the effect on oxidative stress of an exercise intervention that reduced body fat, and the first such exercise intervention study to include a substantial proportion of black children.
authors.affiliation: Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, Medical College of Georgia, Augusta, GA 30912, USA.
authors.forename: B Adam
authors.initials: BA
authors.lastname: Dennis
authors.forename: Adviye
authors.initials: A
authors.lastname: Ergul
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Gower
authors.forename: Jerry D
authors.initials: JD
authors.lastname: Allison
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Davis
mesh_terms: D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D002648:Child; D003430:Cross-Sectional Studies; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D028421:Isoprostanes / Q000097:blood*; D008055:Lipids / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology / Q000628:therapy*; D009765:Obesity / Q000097:blood / Q000150:complications / Q000517:prevention & control*; D018384:Oxidative Stress; D010101:Oxygen Consumption; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin; D028421:Isoprostanes; D008055:Lipids