title: L-folic acid supplementation in healthy postmenopausal women: effect on homocysteine and glycolipid metabolism.
abstract: BACKGROUND
  Hyperhomocysteinemia as well as alterations of glycemic and lipidic metabolism are recognized as risk factors for cardiovascular diseases.
  
  
  OBJECTIVE
  The aim of this study was to examine the effect of L-folic acid supplementation on homocysteine (Hcy) and related thiols, such as cysteine (Cys) and Cys-glycine (Cys-Glyc) pathways and their relationship to glucose, insulin, and lipidic metabolism in normoinsulinemic postmenopausal women.
  
  
  METHODS
  This study was a randomized placebo, not double-blind, trial.
  
  
  METHODS
  The study was performed in an academic research center.
  
  
  METHODS
  Twenty healthy postmenopausal women were selected. No patient was taking drugs known to affect lipid or glucose metabolism.
  
  
  METHODS
  Patients underwent two hospitalizations before and after 8 wk of L-acid folic (7.5 mg/d) or placebo administration. The glycemic metabolism was studied by an oral glucose tolerance test and a hyperinsulinemic euglycemic clamp. Hcy metabolism was studied by a standardized oral methionine-loading test.
  
  
  METHODS
  Hcy, Cys, and Cys-Glyc, basally and after a methionine loading test, were measured. Basal insulin, glucose, and peptide C levels as well as area under the curve for insulin, area under the curve for peptide, hepatic insulin extraction, and metabolic index were assayed. The total cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol levels and the cholesterol/HDL and LDL/HDL ratios were also measured.
  
  
  RESULTS
  The total basal Hcy concentration and the plasma postmethionine loading Hcy values were significantly decreased (P < 0.01) in L-folic acid-treated patients, whereas postmethionine loading Cys-Glyc levels were markedly increased (P < 0.02). Furthermore, L-folic acid intake induced a significant improvement in carbohydrate metabolism through an increase in fractional hepatic insulin extraction (P < 0.05) and peripheral insulin sensitivity (P < 0.02) in normoinsulinemic women. HDL levels considerably increased, inducing an improvement in other atherosclerotic indexes, such as cholesterol/HDL and LDL/HDL ratios (P < 0.03).
  
  
  CONCLUSIONS
  These results show that folic acid supplementation lowers plasma Hcy levels and improves insulin and lipid metabolism, reducing the risk of cardiovascular disease.
authors.affiliation: Department of Obstetrics and Gynecology, Catholic University of Sacred Heart, L. go Gemelli 8, 00168 Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Villa
authors.forename: Concetta
authors.initials: C
authors.lastname: Perri
authors.forename: Rosanna
authors.initials: R
authors.lastname: Suriano
authors.forename: Francesco
authors.initials: F
authors.lastname: Cucinelli
authors.forename: Simona
authors.initials: S
authors.lastname: Panunzi
authors.forename: Micaela
authors.initials: M
authors.lastname: Ranieri
authors.forename: Cristina
authors.initials: C
authors.lastname: Mele
authors.forename: Antonio
authors.initials: A
authors.lastname: Lanzone
mesh_terms: D001786:Blood Glucose; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D003545:Cysteine / Q000097:blood; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D006397:Hematinics / Q000008:administration & dosage*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D007328:Insulin / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause / Q000378:metabolism; D012307:Risk Factors; D040242:Risk Reduction Behavior
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D006397:Hematinics; D007328:Insulin; D006710:Homocysteine; D005492:Folic Acid; D003545:Cysteine