AB0570 BONE MINERAL DENSITY, TRABECULAR BONE SCORE AND PROXIMAL FEMUR 3D-DXA ANALYSIS IN PSORIATIC DISEASES

Abstract

Background:current data regarding areal bone mineral density (aBMD) in patients with psoriasis (PsO) or psoriatic arthritis (PsA) are conflicting. Results on Trabecular Bone Score (TBS) in these patients are lacking. 3D-analysis of cortical and trabecular bone from hip DXA is a new method for non-invasive bone structure assessment, providing separate assessment of the cortical layer and trabecular macrostructure.Objectives:Case-control study (NCT02849795)Methods:52 PsO and 52 PsA cases (CASPAR criteria) were each paired to a control subject matched for age, sex and body mass index (BMI). aBMD measurements at (L2-4) lumbar spine (LS), femoral neck (FN) and total hip (TH) were performed using DXA, Lunar GE. TBS was calculated from antero-posterior L2-L4 BMD image using TBS iNsight V1.8 (Med-Imaps, Pessac, France). 3D-SHAPER software (version 2.10, Galgo Medical S.L, Barcelona, Spain) was used to derive a 3D analysis from the hip DXA scans.Results:LS and TH aBMD measurements did not differ between patients with PsO or PsA and their respective controls (Table 1). Left FN BMD was higher in patients with PsO compared to controls (p = 0.028), a difference not observed on the right FN. TBS was similar in PsA patients and their controls while decreased values were observed in PsO patients (p = 0.04). In 3D analysis, none of the parameters differed between patients with PsA and their controls. For patients with PsO, no difference was found with the controls for 3D-DXA parameters from the right FN, while total hip cortical surface BMD (sBMD) of the left FN was higher in PsO compared to their controls (p = 0.037). Similarly, cortical thickness (Cth) of the intertrochanteric and shaft regions of the left FN was also higher in PsO (p = 0.032 and p = 0.033). Finally, analysis by region (neck, intertrochanteric and shaft) showed higher values for cortical sBMD from each region of the left FN in the patients with PsO (all p <0.05).Conclusion:Our results showed comparable aBMD, TBS and 3D proximal femur parameters in patients with PsA and controls. This supports that PsA population is not at increased risk of osteoporosis. In patients with PsO, while LS bone microarchitecture seems impaired, FN displayed better cortical parameters than the controls. Although these results seem marginal, they support the fact that patients with PsO are not at high risk for osteoporosis and hip fracture.Table 1.PsA: psoriatic arthritis; PsO: psoriasis; M: male; F: female; BMI: body mass index; PASI: psoriasis area severity index; CPDAI: composite psoriatic disease activity index; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; aBMD: areal bone mineral density; LS: lumbar spine; FN: femoral neck; TH: total hip; TBS: trabecular bone score; sBMD: surface bone mineral density; Cth: cortical thickness; quantitative data are mean ± standard deviation; * and ***: paired t test comparing patients with psoriatic arthritis or psoriasis alone to their respective controls; * p < 0.05; *** p < 0.001).PsAPsA controlsPsOPsO controlsN52525252Age (years)52.5 ± 11.752.8 ±11.150.5 ± 12.850.7 ± 12.8Sex (M/F)25/2725/2738/1436/16Menopausal women18 (67%)16 (59%)5 (36%)8 (50%)BMI (Kg/m2)27.4 ± 5.927.7 ± 6.428.4 ± 5.828.2 ± 6.1PASI2.4 ± 4.18.4 ± 4.9CPDAI7.4 ± 3.3ESR (mm/h)19.8 ± 16.6 ***6.9 ± 5.810.7 ± 8.8 ***6.4 ± 6.4CRP (mg/L)10.5 ± 11.7 ***3.9 ± 4.86.0 ± 9.04.7 ± 5.5LS (L2-4) aBMD (g/cm2)1.27 ± 0.491.20 ± 0.201.25 ± 0.211.20 ± 0.18FN aBMD (g/cm2) right0.96 ± 0.120.94 ± 0.140.98 ± 0.150.98 ± 0.15 left0.96 ± 0.160.93 ± 0.121.0 ± 0.14 *0.97 ± 0.13TH aBMD (g/cm2)1.01 ± 0.161.00 ± 0.151.11 ± 0.221.06 ± 0.21L2-L4 TBS1.32 ± 0.111.32 ± 0.151.23 ± 0.15 *1.30 ± 0.16Cortical sBMD (left FN) (mg/cm2)169.7 ± 32.8163.1 ± 29.7182.0 ± 31.0 *173.5 ± 30.3Cth intertrochanteric (left FN) (mm)1.91 ± 0.201.94 ± 0.182.03 ± 0.23 *1.97 ± 0.19Cth shaft (left FN) (mm)2.98 ± 0.313.01 ± 0.283.19 ± 0.36 *3.09 ± 0.29Cortical sBMD (left FN) (mg/cm2)neck135.27 ± 26.9129.67 ± 21.9140.29 ± 24.2 *134.6 ± 22.5intertrochanteric162.32 ± 31.1155.34 ± 29.3171.39 ± 29.1 *163.1 ± 28.9shaft cort269.20 ± 49.0257.12 ± 47.3286.2 ± 47.5 *272.7 ± 45.2Disclosure of Interests:ERIC TOUSSIROT: None declared., Renaud Winzenrieth Employee of: GALGO MEDICAL, maxime DESMARETS: None declared., Daniel Wendling: None declared., Francois AUBIN: None declared., Gilles DUMOULIN: None declared.