CGM Reduces Glycemic Events, Hospitalizations in Older Adults, Regardless of Diabetes Type

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An analysis of Veterans Affairs data from more than 20,000 people with diabetes provides an overview of the associations of CGM initiation with improved glycemic control and reduced hospitalization in this patient population.

An analysis of real-world data from more than 20,000 individuals with type 1 or type 2 diabetes (T2D) in the Veterans Affairs Health Care System suggests initiation of continuous glucose monitoring was associated with greater glucose control and led to a reduction in clinical events.

A retrospective observational cohort study with more than 5000 patients with type 1 diabetes (T1D) and more than 15,000 patients with T2D, results of the study provide further insight into the benefits of continuous glucose monitor (CGM) initiation in older patients with different types of diabetes.1

“This study indicates, in a large national cohort, that initiation of CGM was associated with meaningful improvements in HbA1c in both patients with T1D and those with T2D using insulin,” investigators wrote.1 “Importantly, these improvements in glycemic control were accompanied by a general trend toward reduced risk of admission to an ER or hospitalization for hypoglycemia or hyperglycemia. There was an even more consistent reduction in risk of all-cause hospitalization in both T1D and T2D.”

As data related to CGM use continues to emerge and the ease-of-use improves2, interest in exploring the potential of these devices in different population has grown in tandem. In the current study, a team led by Peter Reaven, MD, of the Phoenix Veterans Affairs Health Care System, and colleagues from the University of California, Los Angeles sought to estimate the benefits associated with CGM initiation, with a specific interest in the effects on glycemic control and adverse event risk, older adults with T1D or T2D. With this in mind, investigators designed their research endeavor as a retrospective observational cohort study within the Veterans Affairs Health Care System from January 1, 2015 through December 31, 2020.1

Investigators designed their study with long-term glucose control and incidence of hypoglycemia- or hyperglycemia-related admission to an emergency room or hospital and all-cause hospitalization as the primary outcomes of interest. Benefits of CGM initiation were estimated through comparisons of outcomes of interest among cohorts of propensity score overlap weighted initiators of CGM and nonusers at 12 months.

Overall, 5015 patients with T1D and 15,706 patients with T2D were identified for inclusion in the current study. Investigators pointed out similar numbers of nonusers were also identified for inclusion. The overlap weighted cohort of T1D patients included 3518 nonusers and 5015 users. The overlap weight cohort of T2D patients included 29,912 nonusers and 15,706 users.1

Upon analysis, results indicated declines in HbA1c at 12 months were significantly greater in CGM users with T1D (mean difference, -0.26% [95% CI, -0.33 to -0.19]) and T2D (-0.35% [95% CI, -0.40 to -0.31]) than in nonusers at 12 months, with investigators pointing out a greater proportion of patients using CGM achieved an HbA1c of less than 8% and less than 9% than those not using CGM.1

When assessing risk of events and hospitalization, results indicated CGM initiation was associated with a significantly reduced risk of hypoglycemia (Hazard Ratio [HR], 0.69 [95% CI, 0.48 to 0.98]) and all-cause hospitalization (HR, 0.75 [95% CI, 0.63 to 0.90]) among patients with T1D. In patients with T2D, CGM use was associated with a reduction in risk of hyperglycemia (HR, 0.87 [95% CI, 0.77 to 0.99]) and all-cause hospitalization (HR, 0.89 [95% CI, 0.83 to 0.97]). Investigators pointed out multiple patient subgroups defined by baseline age, HbA1c, hypoglycemic risk, and follow-up CGM use experienced even greater responses to CGM use.1

“This large real-world study demonstrated CGM initiation in T1D and T2D was linked to clinically meaningful and sustained improvements in glucose control and reductions in risk of hypoglycemic and hyperglycemic events contributing to ER or hospital admissions as well as to all-cause hospitalizations,” investigators wrote.1 “Study results also highlight that patient baseline characteristics and consistency of CGM use seem important determinants of the types of outcomes most likely to improve with initiation of CGM.”


  1. Reaven PD, Newell M, Rivas S, et al. 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. 2023. doi:10.2337/dc22-2189
  2. Campbell P. Study finds Dexcom G7 setup is easier, requires fewer tasks for older adults than previous generations. Endocrinology Network. Published November 10, 2022. Accessed February 21, 2023.