Association of Time in Range Parameters Using Continuous Glucose Monitoring with Microvascular Complications in Patients with Type 2 Diabetes Mellitus

Abstract

Background:
Type 2 diabetes mellitus (T2DM) is associated with progressive microvascular complications, including diabetic retinopathy, nephropathy, and neuropathy. Although glycated hemoglobin (HbA1c) remains the standard marker of glycemic control, it does not reflect daily glucose fluctuations or glycemic variability. Continuous glucose monitoring (CGM)-derived Time in Range (TIR) provides a comprehensive assessment of glucose patterns and may serve as an important marker associated with diabetes-related complications. This study aimed to evaluate the association between CGM-derived TIR parameters and microvascular complications in patients with T2DM.

Methods:
This observational study included patients with T2DM who underwent continuous glucose monitoring. Demographic characteristics, clinical parameters, HbA1c levels, and CGM-derived metrics, including TIR, Time Above Range (TAR), Time Below Range (TBR), and glucose variability, were assessed. Microvascular complications were evaluated through appropriate clinical and laboratory assessments. The association between TIR parameters and microvascular complications was analyzed using appropriate statistical methods.

Results:
A total of 200 patients with T2DM were included in the analysis. Microvascular complications were present in 59% of participants. Patients with microvascular complications had significantly lower TIR compared with those without complications (43.2 ± 15.6% vs 70.9 ± 13.8%, p<0.001). They also demonstrated higher HbA1c levels, increased TAR, and greater glucose variability. Lower TIR was significantly associated with diabetic retinopathy, nephropathy, and neuropathy. Multivariate analysis showed that reduced TIR remained independently associated with microvascular complications after adjustment for clinical factors and HbA1c.

Conclusion:
CGM-derived Time in Range is significantly associated with microvascular complications in patients with T2DM and provides additional information beyond HbA1c for assessing glycemic control. Incorporation of TIR into routine diabetes management may improve risk stratification and support individualized strategies for prevention of diabetes-related complications.