Correlation of HbA1c and Continuous Glucose Monitor Time in Range

Area of Science:

• Endocrinology
• Metabolic Diseases
• Pharmacotherapy

Background:

• Limited literature exists on the correlation between HbA1c and time in range (TIR) in type 2 diabetes patients using continuous glucose monitors (CGMs).
• Existing studies often do not assess crucial data like time spent in low or very low blood glucose levels.

Purpose of the Study:

• To evaluate the relationship between a reduced HbA1c and an increased TIR in patients with type 2 diabetes utilizing CGMs.
• To assess the impact of interdisciplinary team interventions on glycemic control metrics.

Main Methods:

• Retrospective chart review of adult patients with type 2 diabetes using CGMs for at least 3 months.
• Data included demographics, comorbidities, medications, HbA1c, and CGM metrics (TIR, time in hypoglycemia) at baseline and 3-month follow-up.
• Statistical analysis employed Fisher's exact, chi-square, and Mann-Whitney U tests.

Main Results:

• HbA1c levels decreased from 8.6% to 7.5% (P = 0.002) over 3 months.
• Time in range (TIR) increased from an average of 55.5% to 65.1% (P = 0.007).
• A significant inverse correlation was observed between HbA1c reduction and TIR increase (r = -0.7, P < 0.001).

Conclusions:

• A strong inverse relationship exists between HbA1c and TIR, indicating improved glycemic control with CGM use.
• Interdisciplinary interventions, particularly pharmacist-led medication adjustments, effectively improve glucose variability and TIR.
• While TIR improved, a slight increase in time spent in low or very low glucose levels was noted post-intervention.