Declining diabetes mortality and widening regional disparities in Korea (1998–2024)

Background: Diabetes mortality has decreased in many high-income countries, but it remains unclear whether these improvements have occurred evenly across regions. We examined long-term national and municipal-level trends in diabetes mortality in Korea and assessed changes in regional disparities over time.Methods: We used nationwide cause-of-death microdata from Statistics Korea for 1998–2024 to identify deaths for which diabetes was recorded as the underlying cause. Annual crude death rates and age- and sex-standardized death rates (ASDRs) were calculated at the national and municipal levels, with the 2005 Korean population used as the standard. Relative regional disparity was evaluated using the population-weighted Gini coefficient of municipal-level ASDRs.Results: From 1998 to 2024, the national ASDR decreased by 69.0%, from 27.4 to 8.5 per 100,000 population, whereas the crude death rate changed little, from 21.2 to 21.7 per 100,000 population. Mean municipal ASDRs followed a similar downward trend, decreasing from 28.8 to 8.9 per 100,000 population. However, relative regional disparity increased during the same period, with the Gini coefficient rising from 0.14 to 0.24. This pattern was observed consistently within both metropolitan and nonmetropolitan areas.Conclusions: Diabetes mortality in Korea decreased substantially over 27 years, but relative regional disparities across municipalities widened. Further research is needed to identify the factors that contributed to these divergent national and subnational trends.