Abstract Background The optimal glycemic target for older adults with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) remains controversial. This study analyzed longitudinal HbA1c trajectories to compare glycemic-mortality associations between older and younger adults, providing real-world evidence for individualized glycemic management. Methods This retrospective multicenter cohort study utilized the Tianjin Health and Medical Big Data Super Platform (2000–2025), including 2,037 older adults as the primary cohort and 6,075 younger adults as controls. Group-based trajectory modeling (GBTM) identified latent HbA1c evolution patterns. LASSO regression, multivariate Cox proportional hazards models, and Kaplan-Meier curves assessed mortality associations. A five-trajectory model refined the optimal glycemic range, with robustness confirmed through subgroup and sensitivity analyses. Results Over a median follow-up of 4.56 years, 213 deaths (10.5%) occurred in older adults. Three trajectories were identified: Low-stable (38.5%, mean HbA1c 5.12%), Medium-declining (40.9%, 6.62%), and High-stable (20.6%, 8.50%). In younger adults, both High-stable and Medium-declining trajectories were associated with increased mortality risk; in older adults, only the High-stable trajectory significantly elevated risk (HR 1.73, P = 0.006). Five-trajectory analysis demonstrated that maintaining HbA1c between approximately 6.66%–7.94% did not increase mortality risk, whereas progressive hyperglycemia ≥8.20% significantly increased risk (HR 1.75, P = 0.021). Effective glycemic reduction mitigated hyperglycemia-associated harm. Conclusion Older adults with T2DM and CKD exhibit distinct glycemic-mortality patterns compared to younger patients. Maintaining HbA1c between 6.5%–8% was associated with optimal survival outcomes, whereas sustained hyperglycemia exceeding 8% warrants active intervention. Individualized relaxed glycemic targets may optimize the balance between survival benefit and treatment burden in this population.
XiaoLong et al. (2026) studied this question.