P002 Combined associations of obesity and physical activity on pain, fatigue, stiffness, and anxiety with Spondyloarthropathies: a UK Biobank analysis
Authors: Roberts Matthew J , Johnson William , Qooja Sepehr , Moorthy Arumugam , Bishop Nicolette C 
Published: December 2024

Abstract

Background and aims
Inflammatory spondyloarthropathies (ISpAs) are associated with pain, fatigue, stiffness, and anxiety. The guidance on lifestyle management for ISpAs from the National Institute for Care and Excellence (NICE) and the European Alliance of Associations for Rheumatology (EULAR) is non-specific and vague, mostly drawing from studies on rheumatoid and osteoarthritis(1). This distinction is crucial because the associations of lifestyle modification with symptom severity may differ between diseases due to the unique joint involvement, underlying mechanisms, and symptoms in ISpAs compared to rheumatoid and osteoarthritis(2,3). We investigated the combined associations of obesity and physical activity with multiple symptom severity outcomes in ISpAs to help create specific lifestyle guidelines for ISpAs.

Methods
The relationship between body mass index (BMI), physical activity, and symptom severity (spinal and general pain, fatigue, anxiety, mobility) was examined in people with ISpAs (n = 1,577). BMI categories were normal weight (18·5-24·9 kg/m2), overweight (25·0-29·9 kg/m2), and obese (≥30 kg/m2). Physical activity was assessed via the International Physical Activity Questionnaire (low&lt;600 metabolic equivalent of task (MET)-min/week, moderate≥600METs, high≥3000METs). Low activity is equivalent to less than 3 hours of walking per week. Statistical models adjusted for confounders, including medication, estimated the likelihood (odds ratios; OR) of higher symptom severity across BMI and physical activity categories. Spinal pain was the primary symptom severity outcome as it is the most common symptom for ISpAs.

Results
Overweight and obesity, compared to normal weight, were linked to higher severity of all symptoms, with stronger associations for obesity (OR ≥ 2·34, P &lt; 0·001) than overweight (OR ≥ 1.37, P ≤ 0·032). Moderate activity was associated with optimal management of all symptoms. Compared to low activity, moderate activity was associated with lower severity of all symptoms (OR ≤ 0·77, P ≤ 0·032). However, although high activity was associated with lower severity of fatigue, anxiety, and mobility issues compared to low activity, (OR ≤ 0·74, P ≤ 0·029), associations with spinal and general pain were not significant (OR ≤ 0·80, P ≥ 0·056). Statistical modelling (Figure 1) highlighted an important message, in that even low levels of physical activity significantly reduced spinal pain compared to complete inactivity. No BMI-by-physical activity combinations were detected, indicating physical activity benefits all BMI groups to a similar extent. P002 Figure 1.The relationship between body mass index (Panel A) and physical activity (Panel B) with spinal pain. Bold lines at 25·0 and 30·0 on panel A demonstrate the starting point of overweight and obesity, respectively. Bold lines at 600 and 3000 on panel B demonstrate the starting point of moderate and high activity, respectively. MET; metabolic equivalent of task. Spinal pain is rated from 0-10 (0=no pain, 10=pain as bad as it could be). Low activity (&lt;600 METs) is equivalent to less than 3 hours of walking per week.

Conclusions
NICE and EULAR guidance for ISpAs should emphasise maintaining a normal weight. Moderate physical activity is optimal for reducing symptom severity and should be promoted in lifestyle guidance.

References
1. Gwinnutt, J. M. et al. RMD open 8, (2022).
2. Navarro-Compán, V., et al. Ann. Rheum. Dis. 80, 1511–1521 (2021).
3. Sparks, J. A. Ann. Intern. Med. 170, ITC1–ITC16 (2019).