Global burden of MASLD-IBD comorbidity from 1990 to 2021 and trend prediction to 2050

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD), a prevalent chronic liver disorder, imposes a substantial global clinical and economic burden. Emerging evidence underscores inflammatory bowel disease (IBD) as a significant independent risk factor for MASLD. However, the global burden and trends of MASLD-IBD comorbidity remain largely obscured. To evaluate the global MASLD-IBD burden from 1990 to 2021, and project trajectories to 2050, informing proactive public health strategies. Methods: Leveraging the GBD 2021 database, we quantified IBD’s contribution to MASLD via population-attributable fractions (PAF). We analysed the global prevalence, mortality, and disability-adjusted life years (DALYs), stratifying by socio-demographic index (SDI), sex, and age. Estimated annual percentage change (EAPC) assessed 1990–2021 trends; Bayesian age-period-cohort modelling projected 2050 trajectories. Results: In 2021, the global age-standardized prevalence of MASLD-IBD comorbidity reached 171.7 cases (95% UI: 157.3-187.1), with a corresponding DALY rate of 0.5 cases (95% UI: 0.4-0.6) per 10 million population. High-income regions, including North America, Australia, and Western Europe, bore the highest burden. From 1990 to 2021, 20 out of 21 GBD regions exhibited escalating age-standardized prevalence and DALY rates, most markedly in East Asia (prevalence EAPC = 3.18; 95% CI: 2.59-3.77) and East Europe (DALY EAPC = 4.05; 95% CI: 3.32-4.79). Middle SDI regions saw the largest absolute increases, with mortality mirroring DALY trends. Adults ≥ 60 years bore disproportionately higher burdens. By 2050, projections suggest divergent gender trends of rising female burden versus declining male rates. Conclusions: MASLD-IBD comorbidity burdens have risen globally over three decades, necessitating targeted interventions, particularly for ageing populations and high-risk regions. Gender-specific strategies will be critical for mitigating future impacts.