Vitamin D in rheumatoid arthritis and association of disease activity with various laboratory parameters

Abstract

Background: The aim was to validate the association between Vitamin D level and rheumatoid arthritis (RA); evaluate association of stages of disease activity with various parameters such as serum Vitamin D level, RA factor level, anti-cyclic citrullinated peptide (CCP), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels; and evaluate correlation of Vitamin D with various parameters and Disease Activity Score (DAS)-28 score with various parameters. Materials and Methods: This was a prospective comparative study. The sample size was of 100 patients with 50 each in case and control groups. Investigations such as ESR, CRP (quant), anti-CCP, and RA factor were undertaken for case group. Serum 25-hydroxyvitamin D concentration was analyzed for both case and control groups. Disease activity was measured in patients of RA using DAS-28. Mean of Vitamin D level in case and control groups were measured. Association of different stage of disease activity among cases was calculated with various laboratory parameters. Correlation coefficient of Vitamin D with various laboratory parameters and DAS-28 score with various laboratory parameters calculated. Results: The mean Vitamin D level in case group was 18.726 ng/ml, while in control group, it was 42.851 ng/ml. Association of various stages of disease activity was statistically highly significant for CRP and anti-CCP levels. Vitamin D was negatively correlated with serum ESR, while DAS-28 score was positively correlated with serum ESR, CRP, RA factor, and anti-CCP values. Conclusions: Vitamin D deficiency is more common in RA patients. CRP and anti-CCP markers are associated with disease activity. Moderate-to-strong positive linear correlation present between DAS 28 score & CRP and DAS 28 score & anti CCP values respectively.