Late-onset versus young-onset rheumatoid arthritis: comorbidities, disease activity, and treatment patterns in a nationwide real-world registry from Kuwait
Year: 2026
Type: article
Study design: Observational Study
Abstract: Objectives Late-onset rheumatoid arthritis (LORA) may differ clinically from young-onset rheumatoid arthritis (YORA), but real-world data from the Middle East and North Africa are limited. We compared characteristics, comorbidities, disease activity, and treatment patterns between LORA and YORA in the Kuwait Registry for Rheumatic Diseases (KRRD) and assessed whether age at onset was independently associated with disease activity. Methods This retrospective analysis of prospectively collected KRRD data included patients with RA enrolled between January 2012 and April 2026. Patients were classified as YORA (symptom onset 18–59 years) or LORA (≥60 years). Baseline characteristics, disease activity, treatments, and one-year outcomes were compared. Multivariable logistic regression examined factors associated with moderate-to-high disease activity (DAS28-ESR ≥3.2). Sensitivity analyses additionally adjusted for current age, assessed collinearity, and repeated comorbidity and ESR comparisons after age adjustment and within patients aged 60–79 years. Results Among 2,629 patients, 303 (11.5%) had LORA and 2,326 (88.5%) had YORA. LORA patients had shorter disease duration (2.9 ± 4.0 vs. 5.0 ± 7.1 years; p < 0.001) and higher comorbidity burden (2.0 ± 1.5 vs. 0.9 ± 1.2; p < 0.001). Most disease activity measures and treatment patterns were similar. Among 1,402 patients with follow-up of at least one year, disease activity at the last visit was similar (DAS28-ESR mean difference 0.10, 95% CI −0.12 to 0.30), including after inverse-probability weighting and multiple imputation. ESR was higher in LORA (40.9 vs. 33.3 mm/hr; p < 0.001), whereas CDAI was not (mean difference 0.7, 95% CI −0.9 to 2.3). Age at onset was not independently associated with moderate-to-high disease activity (adjusted OR 1.08, 95% CI 0.83–1.41; p = 0.559). After adjustment for current age and sex, the comorbidity excess in LORA was no longer evident (adjusted rate ratio 0.79, 95% CI 0.70–0.89), while ESR remained modestly higher (adjusted ratio 1.17, 95% CI 1.02–1.33). Adding current age did not materially change the onset-group estimate (adjusted OR 1.05, 95% CI 0.76–1.44). Conclusion LORA and YORA showed similar disease activity, treatment patterns, and follow-up outcomes. The higher comorbidity burden in LORA was explained by chronological age, while ESR remained modestly elevated after age adjustment. Findings support treat-to-target principles regardless of age at onset, alongside management of comorbidities in older patients.
Source: Frontiers in Medicine
Authors: Anwar Albasri, Ghaydaa Aldabie, Mohammad Khudadah, Ahmad Alsaber, Adeeba Al-Herz, Khuloud Mohammed, Adel Alawadhi, Eman Hasan, Waleed Alkandari, Aqeel Ghanem, Hoda Tarakmeh, Sawsan Hayat, Naser AlHadhood, Ammar Almathkouri, Ali Aldei, Hebah AlHajeri, Fatemah Baron, Amjad Alkadi, Dalal Alkhudir, Yaser Ali
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7220915995