Background Bone mineral density (BMD) detected by dual energy x-ray absorptiometry (DXA) is a gold standard and powerful predictor of osteoporotic fractures. BMD in patients with psoriatic arthritis (PsA) can be affected negatively by the inflammatory rheumatic disease process and by the therapy itself (1). Some publications revealed higher prevalence of vertebral and non-vertebral fractures in patients with PsA compared to healthy controls (2). Published data on osteoporosis incidence among patients with PsA are contradictory.
Objectives The aim of this study is to establish the prevalence of vertebral fractures in patients with PsA and to evaluate their relationship with disease activity and functional ability.
Methods Eighty-three patients (43 men, 40 women; mean age 56,76±11,67 years) diagnosed with PsA were included in this study. Structured questionnaire was used to collect demographic data, data on disease activity (SE, CRP, DAS28) and functional ability (HAQ, BASFI). Apart from BMD obtained at the lumbar spine (L1-L4) and left hip, lateral scans of the vertebrae from T4 to L4 were performed using a QDR-400 DEXA machine (Hologic). At each of the vertebral bodies six points were placed on the borders of vertebra and vertebral heights were measured (Ha-anterior, Hm-mid and Hp-posterior), along with their ratios and the degree (percent) of deformation according to semiquantitative Genant classification. The deformities were graded into: grade 1 (mild deformities with a reduction of 20-25% in Ha, Hm or Hp), grade 2 (moderate deformities of 25-40%) and grade 3 (severe deformities of more than 40%) (3). Besides the descriptive statistics, data were analyzed using logistic regression.
Results In our cohort, duration of psoriasis was 216.08±142.97 months and duration of psoriatic arthritis 141.7±107.59 months. Thei mean value of CRP was 9.14±1.28 mg/L. The mean value for the following variables were as follows: DAS28 4.32±1.42, BASFI 52.7±24.46 and HAQ was 1.20±0.76. 43 patients (51.81%) had morphometric vertebral fractures. Of these, 29 patients had one vertebral fracture, 7/43 had two vertebral fractures and 7/43 had three vertebral fractures. 30/43 patients had fractures up to grade I, 11/43 patients up to grade II and 3/43 patients had fractures up to grade III. None of the observed variables (age, sex, DAS28, BASFI, HAQ, CRP) have turned out to be predictor for vertebral fractures.
Conclusions In our sample of patients with long-lasting active PsA, 51.81% had morphometric vertebral fracture(s). No demographics, disease activity or functional ability were associated with the presence of fractures. Follow-up studies are necessary to detect possible risk factors for their occurrence.
Grazio S, Cvijetić S, Vlak T, Grubišić F et al. Osteoporosis in psoriatic arthritis: Is there any? Wien Klin Wochenschr (2011)123: 743-750.
Pedreira P, Pinheiro M, Szejnfeld V. Bone mineral density and body composition in postmenopausal women with psoriasis and psoriatic arthritis. Arthritis Res Ther. 2011; 13(1): R16.
Genant HK, Wu CY, van Kuijk C et al. Vertebral assessment using a semiquantitative technique. J Bone Miner Res 1993; 8: 1137-1148.
Disclosure of Interest None Declared