City- and county-level gaps in diabetes mortality improvement in the southeastern coastal region of China from 2005 to 2020, with provincial-level projections to 2030

Objectives: The growing health and economic burden of diabetes in China is a result of fast urbanization and lifestyle changes. This highlights the critical need for a comprehensive analysis of epidemiological patterns and forecasts in order to achieve the "Healthy China 2030" goals. Methods: Socio-Demographic Index (SDI) factors were used to evaluate data on diabetes mortality and YLL (2005-2020) for adults in 84 Fujian counties. Age-Period-Cohort (APC) models were used to examine the impacts of age, period, and birth cohort, while frontier analysis identified areas for health improvement. Bayesian APC (BAPC) modeling was used to forecast future mortality through 2030. Results: Standardized mortality and YLL rates indicated considerable promise for improvement in high SDI cities like Xiamen and Fuzhou. Age-period-cohort analysis reveals that diabetes mortality increased dramatically with age, reaching 464.79/100,000 for those 85 and older. The mortality risk decreased in subsequent generations after peaking in the 1947 birth cohort (RR = 1.51). Bayesian projections suggest the standardized mortality rate will rise to 17.14/100,000 by 2030, with a greater impact on females. Diabetes-related deaths are expected to rise by 58.88% (to 10,891). Conclusion: High-SDI areas like Xiamen and Fuzhou require optimized resource allocation to reduce mortality. Targeted interventions for older adults are required due to aging and cohort effects. As the 2030 burden intensifies, strengthening early screening and regional strategies is essential to mitigate future impacts.