title: Abnormal vascular reactivity at rest and exercise in obese boys.
abstract: BACKGROUND
  Obese children exhibit vascular disorders at rest depending on their pubertal status, degree of obesity, and level of insulin resistance. However, data regarding their vascular function during exercise remain scarce. The aims of the present study were to evaluate vascular morphology and function at rest, and lower limb blood flow during exercise, in prepubertal boys with mild-to-moderate obesity and in lean controls.
  
  
  METHODS
  Twelve moderately obese prepubertal boys [Body Mass Index (BMI: 23.9+/-2.6 kg m(-2))] and thirteen controls (BMI:17.4+/-1.8 kg m(-2)), matched for age (mean age: 11.6+/-0.6 years) were recruited. We measured carotid intima-media thickness (IMT) and wall compliance and incremental elastic modulus, resting brachial flow-mediated dilation (FMD) and nitrate-dependent dilation (NDD), lower limb blood flow during local knee-extensor incremental and maximal exercise, body fat content (DEXA), blood pressure, blood lipids, insulin and glucose.
  
  
  RESULTS
  Compared to lean controls, obese boys had greater IMT (0.47+/-0.06 vs. 0.42+/-0.03 mm, P<0.05) but lower FMD (4.6+/-2.8 vs. 8.8+/-3.2%, P<0.01) in spite of similar maximal shear rate, without NDD differences. Lower limb blood flow (mL min(-1).100 g(-1)) increased significantly from rest to maximal exercise in both groups, although obese children reached lower values than lean counterparts whatever the exercise intensity.
  
  
  CONCLUSIONS
  Mild-to-moderate obesity in prepubertal boys without insulin resistance is associated with impaired endothelial function and blunted muscle perfusion response to local dynamic exercise without alteration of vascular smooth muscle reactivity.
authors.affiliation: Faculty of Sciences, Avignon, France.
authors.forename: L
authors.initials: L
authors.lastname: Karpoff
authors.forename: A
authors.initials: A
authors.lastname: Vinet
authors.forename: I
authors.initials: I
authors.lastname: Schuster
authors.forename: C
authors.initials: C
authors.lastname: Oudot
authors.forename: L
authors.initials: L
authors.lastname: Goret
authors.forename: M
authors.initials: M
authors.lastname: Dauzat
authors.forename: P
authors.initials: P
authors.lastname: Obert
authors.forename: A
authors.initials: A
authors.lastname: Perez-Martin
mesh_terms: D000273:Adipose Tissue; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D015992:Body Mass Index; D001916:Brachial Artery / Q000503:physiopathology*; D002339:Carotid Arteries / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D004108:Dilatation, Pathologic; D015444:Exercise; D006801:Humans; D007328:Insulin / Q000097:blood; D007866:Leg / Q000098:blood supply*; D008055:Lipids / Q000097:blood; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology*; D009765:Obesity / Q000503:physiopathology*; D012039:Regional Blood Flow; D012146:Rest
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids