Background: Many patients with type 2 diabetes (T2D) have suboptimal control and are not meeting their glycemic targets. Use of CGM devices has increased substantially for patients with T2D. However, the effects of rtCGM on glycemia in T2D primary care patients, particularly those not on intensive insulin therapy, in real world settings has not been well studied.

Materials and Methods: This retrospective observational study examined data from 13 U.S. health systems and multispecialty medical groups. Personal rtCGM use was determined from prescription codes. The cohort included patients with a diagnosis for T2D and ≥1 outpatient visit with a primary care provider (PCP) in the 18 months prior to rtCGM use. The outcome was change in hemoglobin A1c (A1c) from baseline to 3-9 months after rtCGM initiation. The cohort was stratified into two groups based on baseline A1c (A1c >7.5 and A1c ≤7.5) .

Results: Between August 1, 2015, and September 30, 2020, 458 T2D patients initiated rtCGM (mean age 61, 50% female, 84% white, 50% commercial insurance, and a mean of 3.7 PCP visits in the prior year) . Of the 458 patients, 64 (14%) were prescribed antidiabetes drugs but not insulin (NIT) , 51 (11%) were prescribed basal but not bolus insulin (NIIT) , and 343 (75%) were prescribed bolus insulin, with or without basal insulin (IIT) . Univariate analysis of change in A1c showed for those with a baseline A1c >7.5 (n=306, 67%) , A1c changed an average of -0.9% (95% CI -0.7, -1.1, p<.001) and varied by diabetes management regimen: NIT -1.13% (SD=2.3%) , p<.01; NIIT -1.59% (SD=2.3%) , p<.001; IIT -0.76% (SD=1.6%) , p<.001. For those with a baseline A1c ≤7.5 (n = 152, 33%) , change in A1c was not statistically significant (0.12%, p=.123) .

Conclusions: These findings suggest, for poorly controlled patients with T2D, regardless of therapy regimen, rtCGM use improved glycemic control. This real-world evidence supports further studies of the benefits of rtCGM in the broader T2D population.


S.Shields: None. G.J.Norman: Employee; Dexcom, Inc. E.L.Ciemins: None.

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