Background Emerging role of vitamin D in immunology and autoimmune disorders has been a worldwide interest in the last decade. Systemic lupus erythematosus (SLE) patients are particularly at a delicate position predisposing them to suffer from vitamin D deficiency due to the multiple risk factors accompanying the disease. Whether vitamin D deficiency is also involved as a risk factor for developing SLE and affecting its course is a considerable concern.
Objectives To estimate prevalence of vitamin D deficiency in SLE and its relation to disease activity and severity.
Methods In our observational cross-sectional study, serum levels of vitamin D from 60 SLE patients and 30 age & sex matched healthy controls (HC) were assessed and estimated for deficiency or insufficiency at 10 and 30ng/ml respectively. Disease activity was evaluated by SLEDAI, irreversible organ damage by SLICC/ACR index and severity by Lupus SDI. Fatigue was measured by visual analogue scale (VAS).
Results Significantly lower levels of 25(OH)D were found in SLE patients (17.6±6.9 ng/ml) in comparison to controls (79.0±28.7 ng/ml)with statistically high significant difference (t=-11.2, p<0.001).High prevalence of vitamin D insufficiency and deficiency was detected 73.3% & 23.3% respectively. Vitamin D had a highly significant negative correlation with SLEDAI (r =-0.495, p<0.001), see figure 1a, SLICC (r =- 0.431, p<0.05) as well as fatigue (r =- 0.436, p<0.05), see figure 1b. After standardization of all clinical variants, regression analysis study showed that there is significantly inverse correlated between vit D and VAS (standardized regression coefficient β=-0.443, p=0.024) and a highly significant correlation between vit D and SLEDAI score (β=-0.940, p=0.012).
Conclusions Vitamin D deficiency & insufficiency were found to be prevalent in SLE patients in our study and related to disease activity & fatigue. Routine screening and consequent repletion of vitamin D if needed is recommended in SLE. Restoring adequate vitamin D level in SLE should be more explored as a potential and simple yet valuable measure to be added to their usual management to alleviate their condition.
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Disclosure of Interest None declared