Folic acid improves endothelial function in children and adolescents with type 1 diabetes.
OBJECTIVE
To evaluate the effect of folate supplementation on endothelial function in children and adolescents with type 1 diabetes.


METHODS
Thirty-six subjects with type 1 diabetes age 13.6+/-2.6 years completed a randomized, double-blind, placebo-controlled crossover trial. Each subject received 8 weeks of oral folic acid (5 mg/d) and 8 weeks of placebo, with an 8-week washout period. Before and after each intervention, we assessed endothelial function by using brachial artery responses to flow (flow-mediated dilatation [FMD]) and glyceryl trinitrate, von Willebrand factor, glucose, hemoglobin A1c, total plasma homocyst(e)ine (tHcy), vitamin B(12), serum folate, and red cell folate (RCF).


RESULTS
Folic acid increased FMD by 2.58 (3.1-5.7) % (95% confidence interval, 1.28-3.88), whereas placebo did not change FMD (-0.42%; 95% confidence interval, -1.67 to 0.83; P<.001). Folic acid increased serum folate by 14 nmol/L (6.2 ng/mL, P<.001) and RCF by 467.2 nmol/L (206 ng/mL, P<.001). Change in FMD was related to change in serum folate (r=0.46, P=.005) and RCF (r=0.39, P=.02). Glyceryl trinitrate responses, von Willebrand factor, tHcy, and hemoglobin A1c were not affected by the intervention.


CONCLUSIONS
Short-term high-dose folic acid improves endothelial function in children and adolescents with type 1 diabetes and normal folate status independently of tHcy.
Peña
Alexia Sophie
AS
Department of Endocrinology, University of Adelaide, Women's and Children's Hospital, 72 King William Road, North Adelaide, South Australia 5006, Australia. alexia.pena@adelaide.edu.au
Wiltshire
Esko
E
Gent
Roger
R
Hirte
Craig
C
Couper
Jennifer
J
D000284:Administration, Oral; D000293:Adolescent; D001783:Blood Flow Velocity / Q000502:physiology; D001916:Brachial Artery / Q000000981:diagnostic imaging; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology*; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects*; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D005492:Folic Acid / Q000097:blood / Q000627:therapeutic use*; D006397:Hematinics / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014463:Ultrasonography
D006397:Hematinics; D005492:Folic Acid