Evolution of Gastrointestinal Inflammatory Diseases and Neoplasm Burden in Super-Elderly Populations: Integrated GBD 2023, CHARLS, and CLHLS Analyses of China and G20 Countries

BACKGROUND: Rapid population aging has profoundly altered the epidemiological profile of gastrointestinal diseases in individuals aged ≥75 years. Although enteric infections (EI) have been effectively controlled through public health interventions, the burden of gastrointestinal inflammatory diseases (GIID) and neoplasms (GIN) continues to evolve. Systematic comparisons of temporal trends, sex differences, and age-subgroup patterns between China and G20 nations remain limited. METHODS: Using GBD 2023 data, we analyzed incident cases, age-standardized rates (ASR), and Disability-Adjusted Life Years (DALYs) of EI, GIID, and GIN among individuals aged ≥75 years in China and 19 G20 countries from 1990 to 2023. Log-linear regression was used to estimate the average annual percentage change (AAPC) in ASR, stratified by sex and 5-year age groups. Complementary individual-level analyses included an XGBoost machine-learning model with SHAP interpretability and disease co-occurrence network analysis. RESULTS: In China, EI ASIR declined sharply (AAPC = -2.24%), while G20 countries showed an upward trend (AAPC = +0.65%). GIID ASIR remained essentially stable in China but rose significantly for Crohn's disease, Inflammatory Bowel Disease (IBD), and ulcerative colitis; G20 countries exhibited an overall decline. GIN shifted toward metabolism-related tumors in China (Colon and rectum cancer AAPC = +1.29%, pancreatic cancer AAPC = +0.74%), whereas esophageal and gastric cancer burdens decreased. China Health and Retirement Longitudinal Study (CHARLS) analysis identified the frailty index as the dominant predictor with clear non-linear threshold effects.Chinese Longitudinal Healthy Longevity Survey (CLHLS) networks revealed arthritis and rheumatic diseases as central hubs strongly linked to digestive disorders, highlighting chronic inflammation as the core driver of multimorbidity. CONCLUSIONS: This study integrates GBD population trends with CHARLS and CLHLS cohort data to characterize the evolving gastrointestinal disease burden in China's super-elderly population.