Decline in Years of Life Lost Due to Diabetes in Korea, 2008–2019: A Cause-Specific Decomposition Analysis

BACKGRUOUND: This study aimed to evaluate trends in years of life lost (YLL) attributable to diabetes and to identify cause-specific contributors to these changes in Korea. METHODS: We analyzed data from the Korean National Health Insurance Service-National Sample Cohort between 2008 and 2019. Standardized mortality ratios (SMRs) were calculated using indirect standardization with age-specific mortality rates of individuals without diabetes as the reference. YLL was defined as the difference in life expectancy between individuals with and without diabetes at a given age. Cause-specific contributions to changes in YLL were estimated using Arriaga's decomposition method. RESULTS: From 2008 to 2019, SMRs declined from 2.19 to 1.55 in males and from 2.04 to 1.36 in females. At age 40, life expectancy among individuals with diabetes increased from 32.53 to 37.81 years in males and from 39.41 to 43.77 years in females, accompanied by a reduction in diabetes-attributable YLL from 8.36 to 5.70 years in males and from 7.51 to 5.21 years in females, representing an approximate 30% decrease. The YLL gap narrowed with increasing age. At age 40, cause-specific decomposition showed that the largest relative reductions in YLL were attributable to diabetes (-40% in males, -46% in females), cardiovascular disease (-37% in males, -52% in females), and kidney disease (-33% in both sexes). CONCLUSION: Diabetes-related YLL in Korea declined substantially over the past decade, primarily driven by reductions in mortality from diabetes, cardiovascular disease, and kidney disease.