title: Association of obesity with patient-reported outcomes in patients with axial spondyloarthritis: a cross-sectional study in an urban Asian population.
abstract: To determine if obesity is associated with poorer patient-reported outcomes (PROs) in patients with axial spondyloarthritis (axSpA), we conducted a cross-sectional study using data of the PRESPOND registry from a tertiary referral center in Singapore between 2011 and 2015. Demographics, clinical, and PRO variables were collected. Patients were divided into three categories: normal (BMI < 23 kg/m2), overweight (23 kg/m2≤ BMI < 27.5 kg/m2) and obese (BMI ≥ 27.5 kg/m2), using Asian BMI classification. The dependent variables are Pain score, Bath Ankylosing Spondylitis Patient Global Score (BAS-G), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Health Assessment Questionnaire (HAQ), and Medical Outcomes Study Short Form 36 version 2 (SF-36). Multivariate regression analyses were performed with these dependent variables and obesity categories, adjusting for confounders. Among 194 patients with axSpA, 32% are overweight while 22% are obese. We found that obese patients had significant poorer pain (β: 11.87, 95%CI 2.13, 21.60) and BAS-G scores (β: 10.18, 95%CI 1.59, 18.76) when compared to normal BMI patients. However, obesity was not associated with BASDAI (β 0.50, 95%CI -0.22, 1.22), BASFI (β 0.08, 95%CI -0.66, 0.81), HAQ (β -0.07, 95%CI -0.21, 0.06), physical component summary (β -0.02, 95%CI -4.47, 4.44), and mental component summary (β -2.85, 95%CI -7.57, 1.88) of SF-36. Obesity was associated with pain score and BAS-G but not with BASDAI, BASFI, HAQ, and SF-36. Further study is needed to examine the causal relationship between obesity and poorer PROs.
authors.affiliation: Department of Pharmacy, National University of Singapore, Singapore, Singapore.
authors.forename: Yi Xuan
authors.initials: YX
authors.lastname: Lee
authors.affiliation: Program in Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore.
authors.forename: Yu Heng
authors.identifier: http://orcid.org/0000-0001-7802-9696
authors.initials: YH
authors.lastname: Kwan
authors.affiliation: Department of Pharmacy, National University of Singapore, Singapore, Singapore.
authors.forename: Wan Yu
authors.initials: WY
authors.lastname: Png
authors.affiliation: Program in Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore.
authors.forename: Ka Keat
authors.initials: KK
authors.lastname: Lim
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: Chuen Seng
authors.initials: CS
authors.lastname: Tan
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, Academia Building, Level 4, 20 College Road, Singapore, 169856, Singapore.
authors.forename: Nai Lee
authors.initials: NL
authors.lastname: Lui
authors.affiliation: Department of Pharmacy, National University of Singapore, Singapore, Singapore.
authors.forename: Eng Hui
authors.initials: EH
authors.lastname: Chew
authors.affiliation: Program in Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore.|Department of Rheumatology and Immunology, Singapore General Hospital, Academia Building, Level 4, 20 College Road, Singapore, 169856, Singapore.
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
authors.affiliation: Program in Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore.
authors.forename: Truls
authors.initials: T
authors.lastname: Østbye
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, Academia Building, Level 4, 20 College Road, Singapore, 169856, Singapore. warren.fong.w.s@singhealth.com.sg.|Duke-NUS Medical School, Singapore, Singapore. warren.fong.w.s@singhealth.com.sg.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. warren.fong.w.s@singhealth.com.sg.
authors.forename: Warren
authors.initials: W
authors.lastname: Fong
mesh_terms: D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications* / Q000628:therapy*; D050177:Overweight; D059408:Pain Management; D010147:Pain Measurement; D000071066:Patient Reported Outcome Measures; D012042:Registries; D012846:Singapore; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000503:physiopathology / Q000628:therapy*; D011795:Surveys and Questionnaires; D014505:Urban Population; D055815:Young Adult
keywords: Disease outcomes; Global; Obesity; Pain; Spondyloarthritis