Prevalence of vitamin D deficiency in Egyptian rheumatoid arthritis patients: correlation with disease activity, functional disability, and bone mineral density

Aim of Work To detect the prevalence of 25-hydroxyvitamin D 3 [25(OH)D 3 ] deficiency in rheumatoid arthritis (RA) patients and its correlation with disease activity, functional disability and bone mineral density (BMD). Patients and methods Cross-sectional case control study included 104 RA patients and 60 matched controls. All patients were subjected to full history taking, clinical examination and routine laboratory investigations in addition to measurements of serum 25(OH)D 3 . Disease activity was assessed by 28-Disease Activity Score (DAS-28) with three variables; tender and swollen 28-joints (T-28 and S-28) and erythrocyte sedimentation rate (ESR). Functional disability was assessed by Modified Health Assessment Questionnaire (M-HAQ). BMD was measured by dual energy x-ray absorptiometry. Results 25(OH)D 3 deficiency was similar in both RA patients and controls (99.1% versus 100%). Although, the mean serum 25(OH)D 3 level was less among RA patients than among controls but there was no statistical significant difference (5.98 ± 6.8 nmol/l versus 8.4 ± 9.6 nmol/l, p = 0.06). There were statistically significant correlations between 25(OH)D 3 and body weight (r = −0.256, p < 0.009), T-28 (r = −0.559, p < 0.001 ), S-28 (r = −0.631, p < 0.001), DAS-28 (p < 0.001), M-HAQ (p < 0.001) scores, ESR (r = −0.39, p < 0.001) and hemoglobin (r = 0.28, p = 0.004). No significant correlation was found between 25(OH)D 3 level and BMD or drug intake. Conclusion Although the prevalence of 25(OH)D 3 deficiency is similar in both RA patients and controls but its deficiency is significantly correlated with increased disease activity and disability but not with BMD