Diabetes in axial spondyloarthritis: a systematic review and meta-analysis of observational studies

Axial spondyloarthritis (axSpA) is a chronic inflammatory condition with an increased risk of cardiovascular disease (CVD). Diabetes is a well-established risk factor for CVD and stroke. The objective of this study was to conduct a systematic review to: (i) identify the prevalence of diabetes in axSpA and (ii) compare the risk of diabetes in patients with axSpA and without. A comprehensive literature search was performed for articles published between 1 January 2000 and 15 November 2023 using Medline, Embase and Scopus (PROSPERO: CRD42023482573). Observational studies reporting prevalence, incidence or risk of diabetes in axSpA were included. Search results were independently screened by at least two reviewers. Quality of included studies were assessed using the JBI critical appraisal tool. Study-specific proportions and odds ratios (OR) were combined in a random-effects meta-analysis. 2257 articles were identified from database searching from which 23 studies were included for analysis amounting to a combined sample size of 65 025 patients. The pooled prevalence of diabetes in people with axSpA was 7.0% (95% CI 5.9-8.0%; predictive interval 2.4-12.9%; p < 0.001). The funnel plot was symmetric suggesting no small-study effects (I² = 98.1% (95% CI 0.05-0.08), τ² = 0.02; p < 0.001). Comparing patients with axSpA to those without, the pooled OR was 1.29 (95% CI 1.10-1.52; predictive interval 0.76-2.22; p = 0.001) for diabetes. The study suggests an increased prevalence and probably an increased risk of diabetes in people with axSpA. Routine screening for diabetes and lifestyle modifications should be encouraged in this cohort.