No 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/m), overweight (23 kg/m ≤ BMI < 27.5 kg/m) and obese (BMI ≥ 27.5 kg/m), 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.

This was a systematic review of the literature on the association between obesity and the outcome of inflammatory rheumatic diseases. We conducted a literature search using PubMed®, Embase and PsycINFO®. Articles were classified into three categories based on the effects of obesity on the outcomes of inflammatory rheumatic diseases. The subject population, country, type of studies, number of patients, measurement of obesity and outcomes assessed were presented. Quality was appraised using Kmet et al's criteria. 4,331 articles were screened and 60 were relevant to the objective. Obesity had a negative, positive and neutral association with outcomes of inflammatory rheumatic diseases in 38 (63.3%) studies with 57,612 subjects, 11 (18.3%) studies with 3,866 subjects, and 11 (18.3%) studies with 3,834 subjects, respectively. In most studies, the disease population had been diagnosed with rheumatoid arthritis (RA). Tumour necrosis factor-α inhibitors were mostly associated with negative outcomes. More studies examining subjects outside Europe and North America and diseases other than RA are warranted.

Age, erythrocyte sedimentation rate, mental component summary score, comorbidities of peptic ulcer disease, and responsiveness to nonsteroidal anti-inflammatory drugs were associated with biologics initiation. It is essential that clinicians recognize these factors in order to optimize therapy.