Onset Age May Not Increase Kidney Disease Burden among Adult-Onset Type 1 DiabetesPatients—A Multi-Center Cross-Sectional Study

Background The incidence of adult-onset type 1 diabetes (T1DM) is rising globally, yet the association between onset age and kidney disease burden—encompassing diabetic kidney disease (DKD), abnormal kidney function, microalbuminuria, and high progression risk of DKD—remains unclear in this population. This multi-center cross-sectional study aimed to investigate this correlation, addressing a critical knowledge gap for clinical practice and public health management. Methods A total of 481 adult-onset T1DM participants from the Guangdong T1DM Translational Medicine Study were stratified by onset age into <30 years (n=269) and ≥30 years (n=212) groups. Demographic, clinical, and laboratory data were collected, and kidney disease indicators were assessed per ADA 2025 standards. Logistic regression analyses were used to evaluate the association between onset age and kidney disease, with adjustments for gender, age of visit, diabetes duration, metabolic factors, and islet autoantibodies. Results The overall DKD prevalence was 22.7%, with no significant differences between the <30 years (23.8%) and ≥30 years (21.2%) groups ( P = 0.505). Similarly, microalbuminuria (23.0% vs. 19.3%, P = 0.325) and high progression risk of DKD (5.2% vs. 5.7%, P = 0.826) showed no intergroup disparities. Although the ≥30 years group had lower median eGFR (105.5 vs. 118.5 ml/min/1.73m², P < 0.001) and higher abnormal kidney function prevalence (23.1% vs. 13.8%, P = 0.008) in unadjusted analysis, these differences disappeared after adjusting for confounding factors. Multivariate logistic regression confirmed onset age ≥30 years was not independently associated with DKD (OR=1.32, 95% CI: 0.53-3.24, P = 0.552), microalbuminuria (OR=1.48, 95% CI: 0.59-3.72, P = 0.399), or high progression risk of DKD (OR=0.43, 95% CI: 0.07-2.78, P = 0.377). Conclusions Onset age may not increase kidney disease burden in adult-onset T1DM patients, differing from type 2 diabetes. Clinical risk assessment should prioritize comprehensive metabolic control (blood glucose, blood pressure, lipids) and regular kidney function monitoring, rather than onset age, providing actionable guidance for optimizing care in this growing population. Clinical trial number: not applicable.