Associations of time in tight range, time in range, and glycated hemoglobin with albuminuria and diabetic kidney disease in adult type 2 diabetes: a cross-sectional study

To evaluate associations of the indicators of glycemic control, HbA1c, continuous glucose monitoring (CGM)-derived time in tight range (TITR; 70–140 mg/dL), and time in range (TIR; 70–180 mg/dL) with albuminuria and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM). This cross-sectional study included 697 patients with T2DM. Albuminuria (UACR ≥ 30 mg/g) and DKD (eGFR < 60 mL/min/1.73 m² or albuminuria) were assessed. Multivariable logistic regression analyzed associations of TITR, TIR, and HbA1c (continuous/tertiles) with albuminuria and DKD. Among the participants, the prevalence of albuminuria and DKD was 34.6% and 37.9%, respectively. After full adjustment, higher TITR and TIR were independently associated with lower odds of albuminuria (TITR: OR 0.98, 95% CI 0.97–0.99; TIR: OR 0.98, 0.96–0.99) and DKD (TITR: OR 0.98, 0.97–0.99; TIR: OR 0.98, 0.96–0.99). The highest (vs. lowest) tertiles of TITR and TIR had significantly reduced risks (for albuminuria; TITR: OR 0.36, TIR: OR 0.42; for DKD, TITR: OR 0.35, TIR: OR 0.40; all p < 0.001). HbA1c showed weaker threshold associations (highest tertile ORs: albuminuria: 2.31, DKD: 2.31; p < 0.05). However, the AUCs for TITR, TIR, and HbA1c showed no significant differences. Restricted cubic spline analysis demonstrated a significant dose-response relationship, wherein higher levels of TITR/TIR were associated with progressively lower risks of albuminuria and DKD. Subgroup analyses revealed that diabetes duration significantly modified the association of TITR (P for interaction ≤ 0.021), with stronger inverse associations observed in patients with diabetes duration ≥ 10 years. In contrast, TIR showed a consistent association across diabetes duration subgroups. Both TITR and TIR are independently associated with albuminuria and diabetic kidney disease. While TIR serves as a consistent marker across different disease stages, TITR may offer refined risk stratification, particularly in individuals with longer diabetes duration. These metrics provide complementary value to HbA1c for assessing renal risk. Not applicable.