# The comparative prevalence of comorbidities across rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis

## TL;DR

This study compares comorbidities in three types of inflammatory arthritis and finds that each has distinct health risks, especially in cardiovascular and neurological conditions.

## Contribution

The study provides the first detailed comparison of comorbidity prevalence across rheumatoid arthritis, psoriatic arthritis, and axial spondyloarthritis.

## Key findings

- Rheumatoid arthritis is strongly associated with atherosclerotic cardiovascular diseases like coronary artery disease and stroke.
- Axial spondyloarthritis is linked to higher odds of heart failure and epilepsy.
- All inflammatory arthritis subtypes show increased prevalence of hypertension and dyspepsia compared to controls.

## Abstract

Inflammatory arthritis (IA) is associated with a high comorbidity burden, yet few studies have compared comorbidities across IA subtypes. We aimed to compare 39 comorbidities across RA, PsA and axial spondyloarthritis (axSpA).

We used UK Biobank data from over 500 000 participants aged 40–69 years. Baseline data for IA and comorbidities were identified via ICD-10 codes, primary care records and/or self-report. Analysis of variance (ANOVA) and chi-squared tests were used for group comparisons, and logistic regression was used to estimate adjusted odds ratios (ORs) for comorbidities in IA versus controls.

Of 230 055 participants (45.4% male; mean age 56.5 years), 1969 had RA, 606 PsA and 797 axSpA. Hypertension (prevalence 9.0–11.1%) and dyspepsia (5.3–7.9%) were more prevalent in IA than in controls. Individuals with RA had significantly higher odds of atherosclerotic cardiovascular diseases, including coronary artery disease (OR 2.1, 95% confidence interval [CI] 1.66, 2.67), stroke/transient ischaemic attack (TIA) (OR 1.78, 95% CI 1.09, 2.89) and peripheral vascular disease (OR 1.90, 95% CI 1.21, 2.99). Those with axSpA had higher odds of heart failure (OR 2.37, 95% CI 1.29, 4.34), atrial fibrillation (OR 1.59, 95% CI 1.03, 2.45) and epilepsy (OR 2.33, 95% CI 1.10, 4.94).

IA is linked to increased comorbidity prevalence, notably in cardiovascular, respiratory and gastrointestinal systems. The prevalence and odds of developing atherosclerotic cardiovascular disease were highest in those with RA. Individuals with axSpA have increased odds of developing epilepsy. These findings highlight the diverse comorbidity profiles across IA subtypes and support tailored management approaches.