POS1129 MAIN PREDICTORS OF STRUCTURAL PROGRESSION IN PATIENTS WITH METABOLIC PHENOTYPE OF OSTEOARTHRITIS

Abstract

Objectivesto determine the main predictors of structural progression in patients with metabolic phenotype of knee osteoarthritis (OA).Methods82 female patients with metabolic phenotype of knee OA (diagnosis of OA according to the ACR criteria, radiologic stages varying I-III Kellgren & Lawrence) aged 40-75 were included in this prospective study. Mean age was 59.1 ± 8.5 years (42-74), BMI was 32.5 ± 3.48 kg/m2, disease duration was 13 (7-19) years. Individual case report forms, which included history of the disease, physical assessment data, VAS knee pain, WOMAC, joint status, comorbidities and previous medications, were filled out for each patient. All patients performed plain knee radiography, ultrasound and MRI (WORMS).Results13 patients (15.9%) showed structural progression at two years of follow-up. When comparing groups with (n=13, group 1) and without (n=69, group 2) structural progression, there were no differences in terms of age, age of disease onset and disease duration. However, in the progression group patients had higher bodyweight: 99 ± 12.9 vs 82.5 ± 8.1 kg (р = 0.0003), they also had higher VAS knee pain (69 (66-73) vs 54 (34-66) mm (p=0.0009), and WOMAC (359 (339-381) vs 255 (200-316) mm (p=0.003)). More patients from the progression group had hypertension (92.3% vs 79.7%) and type 2 diabetes (100% vs 4.3%). MRI showed significant intergroup differences in terms of both frequency and severity of cartilage damage. Cartilage defects (via WORMS) were more frequent in the medial tibial compartment of group 1: 50% vs 4.9%, RR=10.2, 95% CI 2.9-35.1, p=0.0004. Identical trend was found when evaluating bone marrow lesions (BMLs) in the medial (75% vs 27.9%, RR=2.7, 95% CI 1.6-4.5, p=0.003) and lateral (50% vs 16.4%, RR=3.05, 95% CI 1.4-6.8, p=0.02) tibial compartments. Synovitis was verified via MRI in 100% of group 1 patients vs 56.5% (RR=1.8, 95% CI 1.4-2.2, p=0.007).Correlation analysis confirmed the relationship (p<0.05 for all) between metabolic phenotype structural progression and the following parameters: bodyweight (r=0.39), WOMAC pain (r=0.37), type 2 diabetes (r=0.27), synovium thickness via ultrasound (r=0.32), medial (r=0.44) and lateral (r=0.32) tibial compartment subchondral BMLs, medial tibial cartilage defects (r=0.42), presence of subchondral bone cysts in the medial tibial compartment (r=0.38) and femur (r=0.37); lateral tibial (r=0.28) compartment and femur (r=0.28) and also synovitis (r=0.32).Discriminant analysis has shown that the most significant risk factors for structural progression of the metabolic phenotype of knee OA were high WOMAC pain, synovitis, type 2 diabetes and medial tibial compartment BMLs. Based on the selected factors and their coefficients, we have created a formula that allows to predict the risk of structural progression of metabolic OA.Table 1.Discriminant function coefficients to create a model of structural progression of metabolic knee osteoarthritisFactorsDiscriminant function coefficientsROC-curveWOMAC pain0.00608XXXXType 2 diabetes2.11052BMLs in the medial tibial comparment1.3734Synovitis1.19864Constant6.34279AUC=0.802 (0.650-0.954)Model accuracy – 89%Conclusionthis prospective trial has shown that the main predictors for metabolic knee OA phenotype progression are high WOMAC pain, type 2 diabetes, MRI-detected synovitis and BMLs in the medial tibial compartment. These risk factors may serve as a basis for further personalized therapeutic and preventive approaches.Disclosure of InterestsNone declared