Pos0445 the Impact of Regular Physical Exercise and Nutritional Counselling on Body Composition and Disease Activity in Polymyalgia Rheumatica Patients Treated With Oral or Intramuscular Glucocorticoids: A Prospective Monocentric Study in Slovenia

Background: Polymyalgia rheumatica (PMR) leads to significant muscle and lean body mass loss. Inflammation triggers catabolic processes, while pain and stiffness limit physical activity, collectively contributing to rheumatic cachexia. Glucocorticoid (GC) treatment, while suppressing inflammation, poses risks of sarcopenia and frailty with prolonged use. Intramuscular (IM) methylprednisolone (MP) injections, with lower cumulative doses than oral GCs, may present a promising alternative with fewer long-term side effects. Objectives: Evaluate the impact of regular physical exercise and individual nutritional counselling on body composition, clinical and laboratory response, and relapse frequency in PMR patients treated with oral or IM GCs. Methods: A prospective study included newly diagnosed PMR patients (October 2021 - September 2022), randomly allocated to IM or oral MP dosing groups. Both followed a predefined MP tapering regimen. IM MP (120 mg) was administered every 3 weeks for the first 16 weeks, then every 4 weeks with dose reduction by 20 mg every 12 weeks until 60 mg, then by 20 mg every 16 weeks. Oral MP was started at 16 mg/day and tapered every 4 weeks to 12 mg, 8 mg, 6 mg, and finally, a maintenance dose of 4 mg/day. The oral MP group was divided into two subgroups, with one receiving additional interventions: 6 months of regular workout sessions biweekly and nutritional counselling (i.e., intervention group). Follow-up visits were performed adhering to protocol. Body composition assessed by bioelectrical impedance, remission rates, and disease activity measures were compared. Descriptive statistics were used to analyse the studied population. Results: Of the 38 patients (71% female, median (IQR) age 71 (66, 76) years) 13 received IM and 25 oral MP (12 with additional intervention). We observed significant body composition differences between weeks 0 and 24 in intervention (all data for 10 patients) and control groups (Figure 1A). In the intervention group, all patients experienced body weight (BW) loss (average -4.0 kg) with reduced body fat mass (BFM; average -4.6 kg). Concurrently, 70% gained skeletal muscle mass (SMM) and minimal loss of SMM was observed in only 2/10 patients (average change +0.43 kg). In the control group, no significant differences were observed between IM or oral MP dosing groups; BW loss (average -0.8 kg) predominantly occurred at the expense of SMM (average -1.1 kg), and those with BW gain exhibited substantial increase in BFM (average +1.2 kg). After stopping the intervention at week 24 to week 48 (Figure 1B), 5 out of 10 patients gained BFM, and 3 showed an unfavourable trend of SMM reduction. During follow-up, we observed higher ESR values at week 4 and 12 and slower clinical response in the IM MP group at week 4 (Table 1). There was no difference in clinical response between IM and oral MP groups at 12, 24 and 48 weeks and no distinction in response measures for oral MP-treated patients, regardless of intervention. We switched 7 (53.8%) patients from IM to oral MP; 5 due to insufficient effectiveness of IM MP (2 at week 4, 2 at week 12, 1 at week 24), 1 due to relapse at week 48 and 1 due to commencement of anticoagulation at week 48. In the oral MP group 5 (20%) patients relapsed: 2 with symptoms of PMR (1 when lowering the MP dose to 6 mg/day at week 16, 1 at week 24), 3 with symptoms of giant cell arteritis (1 after discontinuing MP at week 24 due to patient's choice). Results should be interpreted with caution due to the study's limited sample size. Conclusion: In our cohort, consistent physical exercise and nutritional counselling led to significant gains in SMM, effectively preventing GC-induced rheumatic cachexia. However, discontinuation of this intervention led to a decline in SMM. Treatment with IM MP exhibited effectiveness in PMR patients but was associated with a higher inadequate response rate and slower clinical and laboratory response compared to oral MP. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.