The relationship between vitamin D and disease activity and functional health status in rheumatoid arthritis

Abstract

We aimed to establish the relationship between serum vitamin D levels and disease activity and health status in rheumatoid arthritis. Sixty-five patients with RA fulfilling ACR criteria for the classification of rheumatoid arthritis and forty healthy controls were included in this study. Disease activity was assessed according to the Disease Activity Score including 28 joint counts. C-reactive protein (CRP, mg/dl) was determined by the nephelometric method. Erythrocyte sedimentation rate (ESR, mm/h) was determined by the Westergren method. Rheumatoid factor (RF, IU/ml) was also determined by the nephelometric method, and RF > 20 IU/ml was defined as positive. 25-OH Vitamin D EIA Kit was used to measure serum 25-OH Vitamin D levels. We found that the mean of the 25-OH D vitamin levels of the patients with RA was not different than that of controls (P = 0.936). We divided patients with RA into three groups according to DAS28 as low activity group (group 1, n = 25), moderate activity group (group 2, n = 25), and high activity group (group 3, n = 15). 25-OH vitamin D levels of the patients in the high activity group (group 3) were found to be the lowest (P < 0.001), and the patients with moderate disease activity had lower levels than those in the mild group (P = 0.033). Serum 25-OH vitamin D levels were significantly negatively correlated with DAS28, CRP, and HAQ (respectively, r = -0.431, P = 0.000, r = -0.276, P = 0.026, and r = -0.267, P = 0.031). Serum vitamin D levels in patients with RA were similar those in the healthy controls, while it significantly decreases in accordance with the disease activity and decreasing functional capacity.

Relationship between Serum 25-Hydroxyvitamin D Levels, Disease Activity and Anti-Cyclic Citrullinated Peptide Antibody Levels in Indian Rheumatoid Arthritis Patients

“…The mean 25-OH vitamin D level in high disease activity group (n = 29) is 58.52 ± 55.13 nmol/l which is significantly low as compared to that in moderate disease activity group patients (96.60 ± 44.13) nmol/l. Our results are in accordance with the findings by Turhanoglu, et al [24]. The small number of patients included in our study may be seen as a limited sample.…”

“…Attar, et al [20] also observed that the mean 25-OH vitamin D levels in patients with RA were similar to the Control group (32.3 ± 14.4 nmol/l) vs. (31.4 ± 16.4 nmol/l). Turhanoglu, et al also reported that the 25-OH vitamin D levels in RA patients and controls were similar [24]. Several studies have confirmed that 25-OH vitamin D deficiency is common in RA.…”

“…Also, Zakeri, et al [27] and Chen, et al [28] showed that 25-OH vitamin D deficiency is linked with the activity levels in RA. The study by Patel, et al also observed a strong inverse correlation between serum 25-OH vitamin D level and DAS score at disease onset It is seen that RA patients with high disease activity have lower 25-OH vitamin D levels as those with low activity score [24]. Our study had 69.05% of the RA patients with high DAS28-CRP score while 30.95% with moderate DAS28-CRP scores.…”

“…Recently, preventive treatment with vitamin D of individuals considered at high risk of developing autoimmune diseases has been proposed [24]. Our findings are of great potential to clinicians as patients may be assessed as failing to respond adequately to disease modification in the presence of 25-OH vitamin D deficiency.…”

“…Epidemiological studies suggest that adequate vitamin D levels decrease the risk of developing autoimmune diseases such as multiple sclerosis, inflammatory bowel disease, RA, and type I diabetes mellitus [23,24]. Several studies have evaluated the correlation between 25-OH vitamin D levels and RA activity.…”