Elevated plasma homocysteine and low vitamin B-6 status in nonsupplementing older women with rheumatoid arthritis

J Am Diet Assoc. 2008 Mar;108(3):443-53; discussion 454. doi: 10.1016/j.jada.2007.12.001.

Abstract

Objective: The purpose of this study was to determine if nonsupplementing older women (aged >or=55 years) with rheumatoid arthritis had higher plasma homocysteine and lower B-vitamin status compared to healthy controls. Elevated plasma homocysteine, a risk factor for cardiovascular disease, may help explain why individuals with rheumatoid arthritis have an increased risk of cardiovascular disease.

Methods: Older, free-living women were classified as rheumatoid arthritis (n=18) or healthy control (n=33). Participants were not using B-vitamin supplements. Fasting blood samples were measured for pyridoxal 5'phosphate (PLP) (the metabolically active coenzyme form of vitamin B-6), folate, red blood cell folate, vitamin B-12, transcobalamin II, homocysteine, C-reactive protein, and lipid concentrations. Participants completed 7-day weighed food records, the Stanford Health Assessment Questionnaire (HAQ), and a visual analog pain scale.

Results: PLP concentrations were lower in the rheumatoid arthritis vs healthy control participants (4.93+/-3.85 vs 11.35+/-7.11 ng/mL [20+/-16 vs 46+/-29 nmol/L]; P<0.01) whereas plasma homocysteine was higher in the rheumatoid arthritis group (1.63+/-0.74 vs 1.15+/-0.38 mg/L [12.1+/-5.5 vs 8.5+/-2.8 micromol/L]; P=0.02). Red blood cell folate concentrations were lower in the rheumatoid arthritis vs healthy control participants [414+/-141 vs 525+/-172 ng/mL [938+/-320 vs 1,190+/-390 nmol/L]; P=0.02). No significant differences were found for plasma folate, vitamin B-12, and transcobalamin II. An inverse correlation was found between PLP concentrations and the HAQ disability index (r=-0.37; P<0.01). A positive correlation was found between homocysteine concentrations and the HAQ disability index (r=0.36; P=0.01). Total cholesterol and low-density lipoprotein cholesterol levels were lower in the rheumatoid arthritis group (cholesterol 191+/-43 vs 218+/-33 mg/dL [4.95+/-1.11 vs 5.65+/-0.85 mmol/L]; P=0.02; low-density lipoprotein cholesterol 110+/-36 vs 137+/-29 mg/dL [2.85+/-0.93 vs 3.55+/-0.75 mmol/L]; P<0.01). No significant differences were seen between groups for protein (g/day), fat (g/day), cholesterol (mg/day), folate (microg/day), vitamin B-12 (microg/day), and vitamin B-6 (mg/day) dietary intakes.

Conclusions: Poor vitamin B-6 status and elevated plasma homocysteine concentrations were seen in older women with rheumatoid arthritis compared to healthy controls and may contribute to their increased risk of cardiovascular disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arthritis, Rheumatoid / blood*
  • Arthritis, Rheumatoid / physiopathology
  • C-Reactive Protein / metabolism
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / etiology
  • Case-Control Studies
  • Cross-Sectional Studies
  • Diet Records
  • Erythrocytes / chemistry
  • Female
  • Folic Acid / analysis
  • Folic Acid / blood
  • Homocysteine / blood
  • Humans
  • Hyperhomocysteinemia / blood
  • Hyperhomocysteinemia / complications
  • Hyperhomocysteinemia / epidemiology*
  • Lipids / blood
  • Middle Aged
  • Nutritional Status*
  • Pyridoxal Phosphate / blood
  • Pyridoxal Phosphate / deficiency
  • Risk Factors
  • Transcobalamins / metabolism
  • Vitamin B 12 / blood
  • Vitamin B 6 / blood
  • Vitamin B 6 Deficiency / blood
  • Vitamin B 6 Deficiency / complications
  • Vitamin B 6 Deficiency / epidemiology*
  • Vitamin B Complex / blood

Substances

  • Lipids
  • Transcobalamins
  • Homocysteine
  • Vitamin B Complex
  • Pyridoxal Phosphate
  • Vitamin B 6
  • C-Reactive Protein
  • Folic Acid
  • Vitamin B 12