A Bidirectional Analysis of Inflammatory Bowel Disease and Gout: Epidemiologic Evidence of a Stronger Association in Crohn’s Disease from a Nationwide Cohort Study in South Korea

<b>Background:</b> Inflammatory bowel disease (IBD) and gout are both chronic inflammatory conditions. Emerging evidence suggests a potential link between IBD and gout through shared inflammatory and metabolic pathways; however, epidemiological findings remain limited and inconsistent, and the temporal direction of this association has not been clearly established. <b>Methods:</b> Through the use of the South Korean National Health Insurance database, we conducted a nationwide bidirectional matched cohort study. In Study I, 10,793 patients with IBD were matched 1:4 to controls without IBD. In Study II, 25,624 patients with gout were matched 1:4 to nongout controls. Exact matching was performed on age, sex, income level, and region of residence, followed by propensity score overlap weighting. Overlap-weighted Cox proportional hazards models were employed to measure adjusted hazard ratios (aHRs) for incident gout (Study I) and incident IBD (Study II). <b>Results:</b> In Study I, patients with IBD experienced a greater occurrence of gout than matched controls (28.40 vs. 24.20 per 10,000 person-years). IBD was linked to a higher likelihood of gout (aHR, 1.16; 95% CI, 1.04-1.29). When stratified by subtype, Crohn's disease (CD) revealed a significant relationship with gout (aHR, 1.25; 95% CI, 1.05-1.48), whereas ulcerative colitis (UC) did not. Notably, the association between IBD (including CD and UC) and gout was consistently significant among participants younger than 45 years. In Study II, gout was not related to an elevated likelihood of IBD (aHR, 1.04; 95% CI, 0.91-1.21) or its subtypes. <b>Conclusions:</b> IBD, particularly CD, was linked to a greater likelihood of gout, especially among younger adults, whereas gout was not associated with subsequent IBD, suggesting an asymmetric association between IBD and gout.