Glycemic control targets in older adults with type 2 diabetes and chronic kidney disease: a trajectory-based survival analysis of glycated hemoglobin.

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 2037 older adults as the primary cohort and 6075 younger adults as controls. Group-based trajectory modeling identified latent HbA1c evolution patterns. LASSO regression, multivariate Cox proportional hazards models, and Kaplan-Meier curves assessed mortality associations. A 5-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 = .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 = .021). Effective glycemic reduction mitigated hyperglycemia-associated harm.

CONCLUSIONS

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.