L-folic acid supplementation in healthy postmenopausal women: effect on homocysteine and glycolipid metabolism.

Abstract

CONTEXT:

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.

DESIGN:

This study was a randomized placebo, not double-blind, trial.

SETTING:

The study was performed in an academic research center.

PATIENTS OR OTHER PARTICIPANTS:

Twenty healthy postmenopausal women were selected. No patient was taking drugs known to affect lipid or glucose metabolism.

INTERVENTION(S):

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.

MAIN OUTCOME MEASURE(S):

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: Paola Villa, Concetta Perri, Rosanna Suriano, Francesco Cucinelli, Simona Panunzi, Micaela Ranieri, Cristina Mele, Antonio Lanzone
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 90 Issue 8 Pg. 4622-9 (Aug 2005) ISSN: 0021-972X [Print] United States
• PMID: 15899950 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Blood Glucose
• Cholesterol, HDL
• Cholesterol, LDL
• Hematinics
• Insulin
• Homocysteine
• Folic Acid
• Cysteine

Topics

• Blood Glucose
• Cardiovascular Diseases (drug therapy, epidemiology, prevention & control)
• Cholesterol, HDL (blood)
• Cholesterol, LDL (blood)
• Cysteine (blood)
• Energy Metabolism (drug effects)
• Female
• Folic Acid (administration & dosage)
• Hematinics (administration & dosage)
• Homocysteine (blood)
• Humans
• Hyperhomocysteinemia (drug therapy, epidemiology, prevention & control)
• Insulin (blood)
• Middle Aged
• Postmenopause (metabolism)
• Risk Factors
• Risk Reduction Behavior