The Effect of Folic Acid Supplementation on Hyperhomocysteinemia and Pulmonary Function Parameters in Chronic Obstructive Pulmonary Disease: A Pilot Study

Abstract

Introduction: Preliminary studies have established the elevated plasma total Homocysteine (tHcy) levels as a risk factor for Chronic Obstructive Pulmonary Disease (COPD). However, studies describing plasma tHcy levels and their relationship to folic acid supplementation and Forced Expiratory Volume in 1 Second (FEV1) status in COPD patients are still lacking. Aim: We investigated the role of hyperhomocysteinemia in COPD and then prospectively examined the relationship between plasma tHcy concentration and effect of folic acid supplementation on FEV1 status in COPD patients. Materials and Methods: This was a prospective case-control study with 50 clinically stable patients of COPD attending the chest clinic of the hospital and 30 healthy controls. The study was done at Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi, India, from August 2011 to February 2013. Plasma levels of Hcy were measured by Enzyme Linked Immuno-Sorbent Assay (ELISA) method. All the subjects were given folic acid therapy (5mg daily) for six weeks duration and were followed up. Repeat plasma Hcy and FEV1 were measured after six weeks. Results: COPD patients had higher baseline plasma tHcy concentration than controls (Mean: 27.42±23.89µmol/L, versus 15.21±15.71µmol/L, p<0.001) and COPD was associated with higher tHcy concentrations also after adjusting for smoking, and age. The mean BMI of the patients was 21.36±4.26kg/m2 . The mean Hcy values decreased from 27.42±23.89µmol/L to 15.2±15.71µmol/L (p-value=0.001) after six weeks of folic acid supplementation. However, no significant change was observed in FEV1 upon folic acid supplementation (FEV1=1.14±0.60 and 1.08±0.56 respectively; p-value=0.654). A significant correlation was observed between BMI and Hcy and also between plasma Hcy levels at the baseline and after six weeks of folic acid supplementation (r=0.283, p=0.04 and r=0.340, p=0.02, respectively) and (r=0.840, p=0.001). Conclusion: COPD patients seem to have a poor folic acid status and as a consequence high tHcy. Also, folic acid supplementation has shown decreased plasma tHcy concentrations, but not necessarily significant change in FEV1.

Keywords

• cardiovascular disease
• chronic inflammation
• forced expiratory volume