Vitamin D status in a monocentric cohort of systemic lupus erythematosus (SLE) patients and correlations with clinical and immunological profile

INTRODUCTION: Numerous studies have found that a majority of systemic lupus erythematosus (SLE) patients have suboptimal vitamin D levels. The major contributory factor is most likely attributed to sun protection measures in order to avoid SLE flares. The objectives of this research included the assessment of vitamin D status and its association with clinical manifestations of SLE, cardiovascular risk factors, autoantibodies, SLE disease activity and damage accrual.

METHOD: This retrospective study involved SLE patients who attended the Rheumatology Clinic at the Hospital Kuala Lumpur from January 2014 to December 2016. Vitamin D was categorised as normal, insufficient or deficient, and the clinical variables were compared across vitamin D categories with chi-squared tests and Pearson correlation coefficient.

RESULTS: We included 216 patients. The mean 25(OH)D concentration was 51.3(Standard Deviation; SD 14.8) nmol/L. Fifty (23.1%) patients had vitamin D deficiency, 120 (55.6%) had vitamin D insufficiency, while 46 (21.3%) had adequate vitamin D levels. There were statistically significant associations between vitamin D status and ethnic group, lupus nephritis and hypertension. No correlations were observed between vitamin D status with SLEDAI score (Pearson correlation coefficient -0.015, p=0.829) as well as SDI score (Pearson correlation coefficient -0.017, p=0.801).

CONCLUSION: SLE patients should be screened for vitamin D concentrations and their levels optimised.