Heterogeneous impact of incident type 2 diabetes on six age-related diseases: A 27-Country European Cohort study

Whether type 2 diabetes (T2DM) accelerates age-related disease uniformly across organ systems or selectively in specific domains remains unresolved, as prior evidence comes largely from single-outcome studies.

Using SHARE (27 European countries, 2004-2020), we matched incident T2DM cases 1:1 to diabetes-free controls on age, sex, and survey wave, yielding six outcome-specific cohorts (n = 1,589-5,781). We fitted Cox proportional-hazards and Fine-Gray competing-risk models with pre-specified subgroup analyses by age at diagnosis (50-59, 60-69, ≥70 years).

Fully adjusted hazard ratios ranged from 1.41 (95% CI 1.23-1.62) for arthritis to 2.34 (1.84-2.97) for stroke. Age at diagnosis modified the associations for heart disease, stroke, cataract, and cancer (P-interaction < 0.05) but not for hypertension (P = 0.071) or arthritis (P = 0.154). The age gradient was steepest for cataract (HR 4.66 at age 50-59 vs. 1.39 at ≥ 70); the diabetes-cancer association disappeared after age 70 (HR 1.01, 95% CI 0.69-1.49).

T2DM accelerates age-related disease selectively; excess risk magnitude and its dependence on age at diagnosis differ substantially by outcome. These findings support risk stratification by organ system and diagnosis age rather than uniform comorbidity prevention strategies.