Vitamin D Status and SLE Disease Activity among Dubai Hospital Lupus Patients

Abstract

Background: Vitamin D deficiency is common worldwide, but is particularly prevalent in the Middle Eastern region, where cultural and religious factors influence its incidence further. As patients with Systemic Lupus Erythematosus (SLE) avoid sun exposure and use medications that could potentially result in vitamin D deficiency, this problem becomes more apparent. Unfortunately, there are no data available on the prevalence of vitamin D deficiency among patients with SLE in our local area. Objective: To assess the prevalence of vitamin D deficiency among patients with a new onset of systemic lupus erythematosus in Dubai, and to determine whether low vitamin D levels are correlated with disease activity. Methodology and Data Collection: a retrospective cohort study of patients with new onset of Systemic Lupus Erythematosus, being diagnosed in less than 1 year and were followed up at Dubai Hospital (UAE) from January 2009 till December 2012. Demographic and clinical data were collected as well as 25(OH) D3 levels. The incidence of vitamin D insufficiency was calculated as a ratio between the numbers of patients with 25(OH) D levels below the specified cut-off values (30ng/ml and 10ng/ml, respectively). SLE was diagnosed according to the American college of rheumatology (ACR SLE) classification criteria of 1997. Patients with drug-induced SLE and vitamin D deficiency were excluded. Results: a total number of 150 patients were included. 87% (n=131) were females and 13% (n=19) were males. The mean vitamin D level at the baseline was 21.6+/- 47 (mean +/- SD), increased to 27.8+/- 16 at 1 year, while the SLEDAI has improved from 8.3+/-5 (mean +/- SD) to 2.4 +/- 2.9 at 1 year respectively. The changes in vitamin D level as well as the SLEDAI were statistically significant with a P value <0.001. Spearman correlation test showed a statistically significant inverse correlation between vitamin D level versus SLEDAI % from baseline to 1-year later. Conclusion: This study showed a direct inverse relationship between lupus activity and a low level of vitamin D. Furthermore, the SLE disease activity score got better with the improvement in vitamin D level, measured at baseline, and after 12 months period.