title: Folic acid does not improve endothelial function in obese children and adolescents.
abstract: OBJECTIVE
  Obese children have severe endothelial dysfunction as measured by flow-mediated dilation (FMD). We have shown that folic acid normalizes endothelial function in children with type 1 diabetes who have a similar degree of endothelial dysfunction but lower total plasma homocyst(e)ine (tHcy) and higher folate status. Our aim was to evaluate, for the first time, the effect of folate supplementation on endothelial dysfunction in obese children.
  
  
  METHODS
  A total of 53 obese subjects (26 male, mean +/- SD age 13.3 +/- 2.2 years, and BMI Z score 2.29 +/- 0.25) participated in a randomized, double-blind, placebo-controlled, parallel trial of oral folic acid (5 mg/day) or placebo for 8 weeks. Before and after the intervention, we assessed endothelial function (FMD), smooth muscle function (glyceryl trinitrate-induced dilatation [GTN]), high-sensitivity C-reactive protein (hsCRP), tHcy, serum folate, red cell folate (RCF), and lipids.
  
  
  RESULTS
  There were no group differences at baseline. FMD did not change with the intervention (folic acid group pre- and postintervention: 6.42 +/- 5.03 and 6.56 +/- 4.79%, respectively, vs. placebo group: 5.17 +/- 3.54 and 5.79 +/- 4.26%, respectively; P = 0.6). Folate supplementation increased serum folate and RCF by 18.4 nmol/l (P < 0.001) and 240.1 nmol/l (P < 0.001), respectively, and decreased tHcy by 0.95 microl (P = 0.008). The intervention did not change GTN, hsCRP, or lipids.
  
  
  CONCLUSIONS
  Folic acid supplementation does not improve endothelial function in obese children without diabetes despite increasing folate status and reducing tHcy. This is in contrast to the response to folate in children with type 1 diabetes.
authors.affiliation: Endocrinology and Diabetes Department, Women's and Children's Hospital, 72 King William Rd., North Adelaide, SA 5006, Australia. alexia.pena@adelaide.edu.au
authors.forename: Alexia S
authors.initials: AS
authors.lastname: Peña
authors.forename: Esko
authors.initials: E
authors.lastname: Wiltshire
authors.forename: Roger
authors.initials: R
authors.lastname: Gent
authors.forename: Lino
authors.initials: L
authors.lastname: Piotto
authors.forename: Craig
authors.initials: C
authors.lastname: Hirte
authors.forename: Jennifer
authors.initials: J
authors.lastname: Couper
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D009765:Obesity / Q000188:drug therapy / Q000503:physiopathology*; D010919:Placebos; D017211:Treatment Failure
chemical_list: D010919:Placebos; D005492:Folic Acid