Evaluation of the Relationship Between Serum Vitamin D Level and Clinical Activation in Patients with Rheumatoid Arthritis and Systemic Lupus Erythematosus

INTRODUCTION: In this study, we aimed to analyze the clinical activity relationship between serum vitamin D level, which is also a steroid hormone, and to investigate the correlation between clinical and laboratory data and possible relationships.
METHODS: A total of 126 adult patients who met the 2019 SLE classification criteria and the 2010 RA classification criteria and were treated in the outpatient clinics of Rheumatology and Physical Medicine and Rehabilitation were included in the study. In all patients. Erythrocyte sedimentation rate and C-reactive protein (CRP) level, vitamin D level, pain assessment with Visual Analogue Scale (VASpain) and Health Assessment Questionnaire (HAQ) were used to assess functional ability and health status in daily life.
RESULTS: 4 patients (72.4%) who participated in the study had RA and 32 patients (27.6%) had SLE. In the SLE group, 27 (84.4%) were female patients, and there was no difference between the two groups in terms of gender. The mean age was 39.32±6.64 years in the SLE group and 50.76±9.07 years in the RA group. While the 25-(OH) vitamin D level in the SLE group was 10.53±3.52, the vitamin D level in the RA group was 14.20±5.28, and the difference between the two groups was significant (p<0.0001). In the RA group, a significant negative correlation was found between the HAQ level and 25-(OH)D measured in terms of clinical activation (p=0.001).
DISCUSSION AND CONCLUSION: n this cross-sectional study, 25-(OH)D levels were lower in SLE, one of the major autoimmune diseases, than in patients in the RA group. A negative correlation of 25-(OH)D level with HAQ was found in RA patients. Monitoring vitamin D levels and raising them to an optimal level is considered clinically important in autoimmune diseases.