Abstract
BACKGROUND: Inflammatory bowel disease (IBD) is a chronic nonspecific intestinal disorder with peak onset ages in adolescents and young adults (AYA, aged 15-39) and a lifelong risk of recurrence. AYA constitute a significant and unique proportion of its disease burden, facing challenges in fertility preservation, psychosocial support, and economic impact. Accurate epidemiological insights are crucial for national disease control and prevention strategies, yet research on AYA IBD remains sparse. This study aims to assess the burden of AYA IBD from 1990 to 2021 by global, regional, national, socio-demographic index (SDI), sex and age group, and to predict the disease burden in 2040. METHODS: Using data from the Global Burden of Disease (GBD) study, we conducted a comprehensive analysis of disability-adjusted life years (DALYs), deaths, incidence, and prevalence of AYA IBD from 1990 to 2021, with subgroup analyses by region, country, SDI, sex and age group. We calculated the estimated annual percentage changes (EAPCs) of age-standardized rates (ASRs) to assess global trends in AYA IBD burden from 1990 to 2021. We also examined the correlations between EAPC and ASR as well as SDI across countries and projected the disease burden to 2040 with Bayesian age-period-cohort (BAPC) model. RESULTS: Globally, AYA IBD DALYs increased from 246,873.18 in 1990 to 320,607.21 in 2021. By 2040, DALYs are projected to continue rising steadily. East Asia saw the most marked increases in age-standardized incidence rate (ASIR) and age-standardized prevalence rate (ASPR), at 3.28% and 2.60%, respectively. Australia experienced the steepest rises in age-standardized DALYs rate (ASDR) and mortality rate (ASMR), at 1.19% and 2.33%, respectively. High SDI countries still had the highest ASDR (21.90/100,000), ASIR (13.65/100,000), and ASPR (109.31/100,000) in 2021. Middle SDI countries exhibited the largest ASDR, ASIR and ASPR increases. In 2021, the EAPCs of ASDR and ASMR were negatively correlated with SDI. Females had higher ASDR, ASMR and ASPR. The highest disease burden was observed in the 35-39 age group. CONCLUSION: AYA IBD represents a significant global public health burden, expected to persist through 2040. With the increasing aging population, policymakers should develop appropriate strategies to mitigate the burden of AYA IBD.