Abstract
BACKGROUND: The 2025 American Diabetes Association guidelines emphasize the benefits of continuous glucose monitoring (CGM) for patients with diabetes receiving insulin therapy. CGM measures interstitial fluid glucose levels, offering an alternative to capillary (finger-stick) devices. This study aimed to evaluate the real-world impact of CGM devices on patients with uncontrolled type 2 diabetes (T2D) compared to traditional blood glucose monitoring (BGM) in a resource-limited population. METHODS: This is a retrospective study of patients 18 years or older, with T2D, with a glycated hemoglobin (HbA1c) > 9% at enrollment during the study period of December 1, 2021, to February 12, 2023, at an inner-city hospital. Patients with T2D using CGM devices were compared to a historical cohort of patients from the same population using BGM devices in the same period. The primary outcome was the HbA1c at 3 months. In total, 64 patients were included in the analysis after screening: 27 in the CGM group and 37 in the non-CGM group. RESULTS: For the primary end point of HbA1c at 3-months, the study found no significant difference between groups. After adjustment for baseline differences (age, HbA1c, creatinine, point-of-care glucose, and number of patients on injectables), average treatment effect (ATE) was -0.48% (SE = 0.27) in favor of the non-CGM group (P = .07). Potential outcome means were 8.8% (SE = 0.17) and 8.3% (SE = 0.2) for CGM and non-CGM groups respectively. Both groups achieved clinically meaningful reduction in HbA1c. CONCLUSION: Our study did not find that CGM titrated regimens resulted in a statistically significant difference in HbA1c change at 3 months compared to non-CGM based treatment. This may indicate that while diabetes technology can help achieve glucose goals in more controlled settings, optimal results in the real world is influenced by many factors, such as insurance coverage, patient adoption, and provider training. More research can be done on identifying factors that yield optimal results in CGM utilization in outpatient settings.