Serum 25-hydroxy vitamin D levels in Egyptian patients with rheumatoid arthritis: Association with disease activity, functional disability and radiological damage

Abstract

Aim of the workThe aim of this study was to examine vitamin D (VD) levels and its associations with disease activity, functional disability and radiological damage in Egyptian patients with RA. Patients and methodsThis study included 150 RA patients and 150 matched controls. All participants were not receiving VD supplements. Serum 25(OH)-D levels were measured in all participants. Serum 25(OH)-D levels at 30 and 20ng/ml were the cut-off values for VD insufficiency and deficiency, respectively. Associations of 25(OH)-D levels with disease activity score associated with C-reactive protein (DAS-28-CRP), functional disability assessed by the Health Assessment Questionnaire (HAQ) and radiological damage as assessed by the modified Larsen method were considered. ResultsLow VD levels were frequent in RA patients (22±9.2ng/ml) compared to the control (28.7±9.6ng/ml) (p<0.001); 42.7% had VD levels <20ng/ml and was <30ng/ml in 80.7%. RA patients with VD deficiency were older, more frequently females and had higher swollen joint count (SJC), tender joint count, visual analogue scale for pain and DAS28-CRP. Only SJC and DAS28-CRP remained significant following the multivariate analysis (p=0.029, p=0.007 respectively), while rheumatoid factor, anti-cyclic citrullinated peptide antibodies, medications used, HAQ and radiologic score had no association with VD levels. ConclusionsVitamin D insufficiency and deficiency are common among Egyptian RA patients and are associated with decreased sun exposure. VD deficiency was related to older age, female gender, swollen joint count and disease activity. Vitamin D levels had no relation with RA functional disability and radiological damage.