Relationship between serum vitamin D concentration and the activity of rheumatoid arthritis

Abstract

Objective: Determine the levels of vitamin D measured in blood serum and their association with the degree of activity of rheumatoid arthritis. 

Methodology: Descriptive, retrospective and cross-sectional study, which included 62 patients with a diagnosis of Rheumatoid Arthritis over 18 years of age according to criteria of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) published in 2010. Data of serum levels of 25-hydroxyvitamin D, disease activity [evaluated with the 28-joint Disease Activity Score (DAS28)] and C-reactive protein (CRP) were collected from the medical records of the rheumatology area of the Teodoro Maldonado Carpo Hospital. 

To establish a relationship between serum levels and disease activity indices (DAS28-PCR), Spearman's correlation coefficient was used. 

Results: The total population studied was 62 patients with RA, of which 91,9% were women and the mean age of the group was 56,4 ± (9,2) years. The mean number of years of disease evolution was 8,6 ± (3,9). The mean concentration of 25(OH)D in the basal determination was 27,0 ± 8,0ng/ml. Regarding the cut-off points of baseline serum vitamin D levels, 41,9% had optimal levels, 41,9% had insufficient levels and 16,2 had deficient values. According to the disease activity by DAS28-PCR, 6,4% were in remission, 32,2% had mild activity, 37,1% had moderate activity, and 24,2% had high activity. 

In relation to disease activity evaluated with DAS28- PCR and serum vitamin D level, the ρ Spearman coefficient showed no relationship between both variables (ρ 0,5).