Association between serum vitamin D metabolite levels and disease activity in patients with early inflammatory polyarthritis
Article first published online: 28 JUN 2007
Copyright © 2007 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 56, Issue 7, pages 2143–2149, July 2007
How to Cite
Patel, S., Farragher, T., Berry, J., Bunn, D., Silman, A. and Symmons, D. (2007), Association between serum vitamin D metabolite levels and disease activity in patients with early inflammatory polyarthritis. Arthritis & Rheumatism, 56: 2143–2149. doi: 10.1002/art.22722
- Issue published online: 28 JUN 2007
- Article first published online: 28 JUN 2007
- Manuscript Accepted: 29 MAR 2007
- Manuscript Received: 1 JUL 2006
- Epsom and St. Helier University Hospitals National Health Service Trust
- Arthritis Research Campaign
Previous in vitro and animal studies have suggested that vitamin D, in particular, its metabolite 25-hydroxyvitamin D (25[OH]D), may have immunomodulatory effects. To study further the potential immunomodulatory effects of vitamin D in humans, we explored the hypothesis that serum vitamin D metabolites may be inversely associated with current disease activity, severity, and functional disability in patients with early inflammatory polyarthritis (IP).
We studied 206 consecutive patients with IP who were enrolled in the Norfolk Arthritis Register between January 2000 and November 2003 inclusive. Patients were studied within 6 months of symptom onset. None of the patients was taking steroids, and all had received <6 weeks of disease-modifying therapy. Associations between serum levels of 25(OH)D and 1,25-dihydroxyvitamin D (1,25[OH]2D) at baseline and the swollen and tender joint counts, Health Assessment Questionnaire (HAQ) scores, C-reactive protein (CRP) levels, and the Disease Activity Score 28-joint assessment (DAS28) scores at baseline and 1 year were assessed.
The median age at symptom onset was 59 years (range 20–88 years), with a median disease duration of 4 months. At baseline, there was an inverse relationship between 25(OH)D levels and the tender joint count, DAS28 score, and HAQ score. The only inverse relationship with 1,25(OH)2D was with the HAQ score. Each 10-ng/ml increase in the level of 25(OH)D was associated with a decrease in the DAS28 score of 0.3 and in the CRP level of ∼25%. At 1 year, the only significant result was an inverse association between baseline vitamin D metabolite levels and the HAQ score; that is, those with higher metabolite levels had lower HAQ scores.
These data provide further support that vitamin D plays an immunomodulatory role in inflammatory arthritis. This association needs to be examined in other cohorts of patients with early IP, as well as in longitudinal studies. If confirmed, the clinical response to vitamin D supplementation should be examined in early IP.