OP0087 COMORBIDITIES IN HAND OSTEOARTHRITIS PATIENTS: PREVALENCE AND IMPACT ON PAIN AND PAIN SENSITIZATION
Authors: Mulrooney E. , Neogi T. , Solveig Dagfinrud H. , Berner Hammer H. , Steen Pettersen P. , Gaarden T. L. , Engedal K. , Kvien T. K. , Magnusson K. , Haugen I. K. 
Published: May 2021

Background:Pain is a hallmark symptom of hand osteoarthritis (OA). A subset of people with hand OA display centrally driven pain characteristics. Pain is driven by person-related factors, but how comorbidities are related to the hand OA pain experience is undetermined. Changes in pain pathophysiology and pain levels by for instants low-grade inflammation, might explain the link.Objectives:The purpose of this study was to determine whether the burden of comorbidities or the individual comorbidities were associated with pain and pain sensitization in persons with hand OA.Methods:These cross-sectional analyses included 282 participants with hand OA from the Nor-Hand study. Comorbidities were assessed by an index (subscales: Disease, Limitation and Treatment, (0-45 scale)) by Sangha et al. The participants completed pain questionnaires; Numeric Rating Scale (NRS) hand pain (0-10) and all joints (0-10), Australian/Canadian (AUSCAN) hand pain subscale (0-20 scale), Western Ontario & McMaster Universities Arthritis Index (WOMAC) pain subscale (0-20) and homunculus (painful joint sites last six weeks, (0-18)). Pressure pain threshold (PPT, handheld algometer, kg/cm2) at tibialis anterior and trapezius and Temporal summation (TS) at the distal radioulnar joint tapped with weighted probe (x10), assessed central pain sensitization. TS-delta was calculated of the first and peak measure of the fifth or tenth tap. Linear regression was used to examine all relations, while adjusted for age, sex, body mass index and education.Results:The participants (89% women, median (IQR) age: 61 (57-66)) showed broad range in pain severity. Most frequent comorbidities were back pain (n=170, 60%), hypertension (n= 85, 30%), stomach ulcer/abdominal disease (n=62, 22%) and depression (n=46, 16%). 281 (99.3%) participants reported >1 comorbidity other than OA. Mean (SD) comorbidity index value was 7.73 (4.25). Higher values were statistically significantly associated with greater pain severity by each pain questionnaire, lower PPT trapezium (borderline significant for PPT tibialis anterior), and greater TS (Table). Similar results were found for subscales. Depression, back pain and hypertension associated with most measures of pain. (Table). Included in the same model, results remained similar (not shown). No statistically significant association between individual comorbidities and pain sensitization (Table).Table.B (95% confidence interval per one SD of the comorbidity index/subscale) are reportedNRS hand painNRS painall jointsAUSCANhand painWOMAC knee/hip painPainful jointsPPT TrapeziumPPT Tibialis AnteriorTSComorbidity Index0.76 (0.12, 0.24)0.76 (0.12, 0.24)1.61 (0.15, 0.37)2.76 (0.26, 0.50)2.76 (0.42, 0.88)-0.38 (-0.15, -0.04)-0.25 (-0.13, 0.01)0.25 (0.02, 0.11)Disease0.69 (0.24, 0.52)0.56 (0.16, 0.46)0.89 (0.22, 0.75)1.34 (0.45, 1.02)2.19 (0.66, 1.76)-0.34 (-0.32, -0.06)-0.24 (-0.29, 0.04)0.23 (0.02, 0.23)Treatment0.56 (0.18, 0.48)0.58 (0.18 0.49)0.80 (0.19, 0.76)1.29 (0.46, 1.06)1.79 (0.47, 1.65)-0.31 (-0.32, -0.44)-0.19 (-0.28, 0.07)0.22 (0.01, 0.24)Limitations0.69 (0.32, 0.70)0.86 (0.44, 0.81)1.16 (0.51, 1.20)1.58 (0.78, 1,53)3.30 (1.72, 3.13)-0.41 (-0.47, -0.13)-0.26 (-0.41, 0.02)0.26 (0.04, 0.33)Depression0.96 (0.29, 1.63)0.66 (-0.04, 1.36)1.74 (0.46, 3.02)0.99 (-0.38, 2.35)3.43 (0.78, 6.09)-0.36 (-1.00, 0.29)-0.44 (-1.25, 0.37)0.02 (-0.50, 0.53)Back pain0.89 (0.38, 1.40)1.10 (0.57, 1.63)1.04 (0.08, 2.00)2.90 (1.87,3.93)2.64 (0.65, 4.64)0.08 (-0.41, 0.56)0.23 (-0.38, 0.84)0.22 (-0.17, 0.61)Hypertension0.64 (0.05, 1.22)0.45 (-0.17, 1.06)1.00 (-0.12, 2.11)1.32 (0.13, 2.52)2.74 (0.44, 5.05)-0.32 (-0.88, 0.23)-0.28 (-0.97, 0.40)0.17 (-0.28, 0.62)Conclusion:Higher burden of comorbidities was associated with greater pain intensity and central pain sensitization. Hypertension, back pain and depression were associated with most pain measures. The lack of relation between individual comorbidities and pain sensitization suggest the burden of comorbidity is more important.Disclosure of Interests:Elisabeth Mulrooney: None declared, Tuhina Neogi: None declared, Hanne Solveig Dagfinrud: None declared, Hilde Berner Hammer Speakers bureau: Speaker fee from Novartis, Lilly and AbbVie, Pernille Steen Pettersen: None declared, Torfinn Lødøen Gaarden: None declared, Knut Engedal: None declared, Tore K. Kvien Speakers bureau: Amgen, Celltrion, Egis, Evapharma, Ewopharma, Hikma, Oktal, Sandoz, Sanofi, Consultant of: AbbVie, Amgen, Biogen, Celltrion, Eli Lilly, Gilead, Mylan, Novartis, Pfizer, Sandoz, Sanofi, Grant/research support from: AbbVie, Amgen, BMS, MSD, Pfizer, UCB (to the institution)., Karin Magnusson: None declared, Ida K. Haugen Speakers bureau: Novartis, Grant/research support from: Pfizer