AB0772 OSTEOPOROSIS AND ITS RELATIONSHIP WITH THE SERUM URIC ACID LEVEL IN PATIENTS WITH PSORIATIC ARTHRITIS

Abstract

Background:Although osteoporosis is an inherent comorbidity in inflammatory rheumatic disease and the risk of bone loss is high in patients with several rheumatic diseases, evidence is limited in psoriatic arthritis (PsA). One of the most prominent features in PsA is increased serum urate (SU) levels. Due to its antioxidant effects and protective role against osteoporosis, high SU levels are associated with increased bone mineral density (BMD) and reduced bone loss in the healthy population, and in patients with rheumatoid arthritis. However, whether this association is also present in patients with PsA has not been investigated.Objectives:The aim of this study was to evaluate PsA patients with respect to the presence of osteoporosis and its association with SU levels.Methods:This ongoing study included 86 patients (68 female, 18 male) who were diagnosed with PsA according to the CASPAR criteria and had indications for BMD testing according to the National Osteoporosis Foundation. Clinical characteristics including body mass index (BMI), pain VAS, patient global VAS, enthesitis, and tender and swollen joint counts were recorded. Evaluations included the PASI, PsAQoL, and HAQ. Disease activity was assessed using the DAPSA, BASDAI, and MDA. Osteoporosis was defined as a BMD T-score of -2.5 or less and osteopenia as a BMD T-score between -1 and -2.5 (WHO osteoporosis).Results:The mean age of the study group was 55.4 (SD:9.2) years and the mean disease duration was 84.5 (SD:91.6) months. Indicators of secondary osteoporosis were type-1 diabetes mellitus (1%), hyperthyroidism (2.3%), early menopause (<age 40) (8.1%), and chronic liver disease (9.3%). As for the steroid use, the rates of never, previous and current users were 33.7%, 20.9% and 22.1%, respectively. Osteoporosis was found in 9.3% and osteopenia in 33.7% of the patients. A history of vertebral compression fractures or any fracture was present in 20.9% of the patients, half of whom were in postmenopausal. BMD L1-L4T- and Z-scores were lower in female patients (p<0.05). DAPSA remission and MDA rates were 6% and 15%, respectively. Bone mineral density was similar across DAPSA disease activity categories (remission-low-moderate-high) (p>0.05). The frequency of osteoporosis did not differ significantly between patients with DAPSA remission and non-remission (p>0.05). The mean L1-L4T- and Z-scores, and BMD g/cm2were significantly higher in patients with MDA than those without MDA (p<0.05). The mean SU level was 5 (SD:1.3) mg/dl, and 18.6% of the patients had a SU level of 6 mg/dl or higher. There was no significant correlation between SU and BMD (p>0.05). BMI showed a weak correlation with femur total T-score (r=0.244). PASI showed weak inverse correlations with femur neck T-score (r=-0.286) and total femur T-score (r=-0.245). BMD variables showed no correlations with disease duration, acute phase reactants, BASDAI, PsAQoL, and cumulative steroid dose.Conclusion:Patients with PsA did not have an increased prevalence of low BMD despite fractures. Osteoporosis was associated with MDA and the severity of psoriasis, but not with DAPSA, SU level, functional impairment, and quality of life.