Continuous Glucose Monitoring Improves Glycemic Control and Reduces Clinical Events in Type 1 and Type 2 Diabetes: Study

The study, published in Diabetes Care, analyzed data from 719 adults with type 1 diabetes and 1,449 adults with type 2 diabetes. It highlighted that CGM metrics, including estimated blood glucose, time in range, and coefficient of variation, are closely linked to all-cause mortality risk.

Clinical trials and observational studies of continuous glucose monitoring have primarily focused on traditional type 1 diabetes (T1D) populations, emphasizing HbA1c and glycemic metrics like time in range. While evidence suggests potential benefits in reducing severe hypo- and hyperglycemia events, data on long-term outcomes, particularly for type 2 diabetes (T2D), remain limited. To fill this knowledge gap, Peter D. Reaven, Phoenix Veterans Affairs Health Care System, Phoenix, AZ, and colleagues evaluated the long-term benefits of initiating continuous glucose monitoring in adults with type 1 diabetes and type 2 diabetes, focusing on sustained glucose control and the reduction of serious clinical events.

For this purpose, the researchers conducted a retrospective observational cohort study within the Veterans Affairs Health Care System to compare glucose control, hypoglycemia- or hyperglycemia-related emergency room or hospital admissions, and all-cause hospitalization between CGM initiators and nonusers over 12 months, using propensity score overlap weighting.

The investigation uncovered the following findings:

• A total of 5,015 CGM users with type 1 diabetes (T1D) and 15,706 CGM users with type 2 diabetes (T2D) receiving insulin were identified from 1 January 2015 to 31 December 2020, along with similar numbers of nonusers.
• CGM users with T1D showed a significantly greater decline in HbA1c (−0.26%) than nonusers at 12 months.
• CGM users with T2D had a significantly greater decline in HbA1c (−0.35%) compared to nonusers at 12 months.
• More CGM users achieved HbA1c levels of <8% and <9% after 12 months compared to nonusers.
• In T1D, CGM initiation was associated with a significantly reduced risk of hypoglycemia (HR 0.69) and all-cause hospitalization (HR 0.75).
• In T2D, CGM use reduced the risk of hyperglycemia (HR 0.87) and all-cause hospitalization (HR 0.89).
• Several subgroups, based on factors like baseline age, HbA1c, hypoglycemic risk, or follow-up CGM use, showed even greater improvements.

The authors found that in a large national cohort, the initiation of continuous glucose monitoring was linked to sustained improvements in HbA1c in patients with later-onset type 1 and type 2 diabetes using insulin.

"This was also associated with a reduced risk of emergency room or hospital admissions for hypoglycemia or hyperglycemia, and all-cause hospitalization," they wrote.

Reference:

Peter D. Reaven, Michelle Newell, Salvador Rivas, Xinkai Zhou, Gregory J. Norman, Jin J. Zhou; Initiation of Continuous Glucose Monitoring Is Linked to Improved Glycemic Control and Fewer Clinical Events in Type 1 and Type 2 Diabetes in the Veterans Health Administration. Diabetes Care 1 April 2023; 46 (4): 854–863. https://doi.org/10.2337/dc22-2189