Background: Spondyloarthritis typically manifests in young adults, although onset after the age of 45 is not uncommon.

Objectives: The primary objective of this study was to compare the clinical characteristics, disease activity, and response to treatment between early-onset spondyloarthritis (EO-SpA) and late-onset spondyloarthritis (LO-SpA).

Methods: This was a retrospective study conducted at a rheumatology department, involving patients diagnosed with spondyloarthritis who met the 2009 ASAS criteria. The study included data from January 2012 to December 2024. The patients were divided into two groups: those with early-onset SpA (≤45 years) and those with late-onset SpA (>45 years). Clinical data, comorbidities, disease activity measures, and therapeutic responses were collected and analyzed.

Results: A total of 474 patients were included. The mean age was 51.85 ± 10 years, and the male-to-female ratio was 0.84. The mean disease duration was 7.15 ± 6.61 years. Late-onset spondyloarthritis was diagnosed in 38.2% of patients. Bivariate analysis revealed a significantly higher proportion of women in the LO-SpA group (p = 0.0001). Moreover, patients with LO-SpA had comorbid conditions, including diabetes (p = 0.0001), hypertension (p = 0.0001), dyslipidemia (p = 0.003), and renal dysfunction (p = 0.013). Peripheral involvement was less common in LO-SpA patients (p = 0.046), and their CRP levels were notably lower (p = 0.001). They were also less likely to develop coxitis (p = 0.001) or inflammatory bowel disease (p = 0.029). Treatment outcomes revealed that patients with LO-SpA responded well to NSAIDs (p = 0.05), but their use of biologic therapies was significantly lower compared to EO-SpA patients (p = 0.0001). Disease activity and functional scores, including the BASDAI and BASFI, showed no significant differences between the two groups.

Conclusion: The prevalence of late-onset spondyloarthritis is likely to increase with the growing aging population. Identifying the distinct characteristics of LO-SpA is essential for improving early diagnosis and providing appropriate treatment strategies. Further research is necessary to explore the underlying mechanisms of LO-SpA and how age impacts disease progression and response to therapy.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.