DOES VITAMIN D INFLUENCE THE ACTIVITY OF THE DISEASE IN PATIENTS WITH PSORIATIC ARTHRITIS?

Background:Several studies have shown an inverse relationship between vitamin D levels (25OHD) and disease activity in patients with rheumatoid arthritis (RA). However, the existing data in patients with psoriatic arthritis (PsA) are poor, and they use the DAS28 index as a peripheral joint activity marker by extrapolation with RA.Objectives:To analyze the relationship between 25OHD levels, disease activity and functional capacity in patients with PsA.Methods:Transversal, observational, descriptive study. We included PsA patients with peripheral joint involvement. We collected demographic variables (gender, age), clinical variables [follow-up, received treatments, TJC (68), SJC (68), VAS] and analytical variables (25OHD, CRP, ESR). We usedDisease activity in psoriatic arthritis(DAPSA) score to measure disease activity, and theHealth assessment questionnaire(HAQ) to determine functional capacity. Levels of 25 OHD <20 ng/ml and between 20-30 ng/ml were considered deficient and insufficient, respectively. Statistical analysis was made with SPSS 22.0. The descriptive analysis results were expressed as percentage and mean ± SD. We used Pearson’s correlation to assess the association between quantitative variables and T test to compare means between dichotomous variables.Results:125 patients were included, the majority women (60.8%), with an average age of 55.4 (SD 12.2) years. The average follow-up was 75.5 (SD 68.3) months. 97.6% of patients had received DMARDs and 40.8% biologics, and almost half of the patients (42.7%) took calcium and 25OHD supplements. The average value of 25OHD was 27.1 (SD 12.1) ng/ml, with 30% of patients having 25OHD deficit and 63.3% insufficiency. The majority of patients had an acceptable disease control, with a mean DAPSA of 10.5 (SD 7,9); and mean of CRP, ESR, TJC and SJC was 6.1 (SD 3.7) mg/l, 10.2 (SD 9.9) mm/h, 1.3 (SD 2.5) and 0.7 (SD 2.1), respectively. The average value of HAQ was 0.6 (SD 0.7). We observed an inverse correlation between 25OHD levels and joint counts, TJC (p=0.02) and SJC (p=0.03). On the other hand, patients with hypovitaminosis D presented a tendency to get higher scores in DAPSA index (P=0.07). We do not observe any relationship between 25OHD and HAQ.Conclusion:As can be seen in our sample, low values of 25OHD are related to increased disease activity in patients with PsA.Disclosure of Interests:L Montolio-Chiva: None declared, Ana V Orenes Vera: None declared, Marta Aguilar-Zamora: None declared, C Vergara-Dangond: None declared, I Vázquez-Gómez: None declared, Eduardo Flores: None declared, A Sendra-García: None declared, À Martínez-Ferrer: None declared, Elia Valls-Pascual Grant/research support from: Roche, Novartis, and AbbVie, Speakers bureau: AbbVie, Lilly, Pfizer, MSD, Novartis, Janssen, Bristol Myers Squibb, UCB Pharma, D Ybáñez-García Speakers bureau: Lilly, Roche, Sanofi, V Núñez-Monje: None declared, I Torner-Hernández: None declared, Juanjo J Alegre-Sancho Consultant of: UCB, Roche, Sanofi, Boehringer, Celltrion, Paid instructor for: GSK, Speakers bureau: MSD, GSK, Lilly, Sanofi, Roche, UCB, Actelion, Pfizer, Abbvie, Novartis