Episodic Real-Time CGM Use in Adults with Type 2 Diabetes: Results of a Pilot Randomized Controlled Trial

Abstract

Introduction: Resistance to initiating insulin therapy is common for people with type 2 diabetes (T2D) using multiple oral agents, resulting in sustained poor glycemic control. We explored a non-pharmacologic option and examined whether adults with T2D and elevated hemoglobin A1c (HbA1c) who were using multiple, non-insulin antihyperglycemics could obtain glycemic benefit from limited, episodic use of real-time continuous glucose monitoring (rtCGM). Methods: A randomized, pilot trial enrolled patients with T2D who were using two or more non-insulin therapies and had HbA1c values of 7.8-10.5%. Following a baseline, 10-day, blinded CGM session, participants were randomized 2:1, rtCGM or self-monitoring of blood glucose (SMBG). Medication changes were not made during the 12-week study unless required for safety; benefits would result from lifestyle changes. The rtCGM group used unblinded rtCGM for three sessions at weeks 0, 4, and 8, and the control group managed diabetes with SMBG and wore blinded rtCGM at week 8. Glycemic endpoints were assessed. Results: Seventy participants were enrolled from eight North American sites and data were available from 68 (n = 45 rtCGM; n = 23 SMBG). Median (IQR) baseline HbA1c was 8.4 (0.8)% and 8.3 (1.2)% and median (IQR) change in HbA1c at week 12 was -0.5 (1.3)% and -0.2 (1.1)% for the rtCGM and SMBG groups, respectively (between-group difference p = 0.74). More than one-third (34.1%) of the rtCGM group vs 17.4% of the SMBG group reached the HbA1c goal of less than 7.5% at week 12 (between-group difference p = 0.12). Compared to run-in, mean (SD) time in range (TIR 70-180 mg/dL) at week 8 increased for the rtCGM group (56.3 [24.5]% vs 63.1 [25.5]%) while it decreased for the SMBG group (68.4 [21.5]% vs 55.1 [30.3]%). HbA1c reductions were not sustained at month 9. Conclusion: In this pilot study, limited episodic rtCGM use in people failing multiple non-insulin therapies resulted in modest, short-term glycemic benefits.

Magnitude of Glycemic Improvement in Patients with Type 2 Diabetes Treated with Basal Insulin: Subgroup Analyses from the MOBILE Study

“…Small studies have shown that modifications in diet, physical activity, and medication adherence motivated by ongoing CGM feedback are important factors in improving glycemic control in this population that may help reduce the need for intensification of treatment regimens. 7 , 8 , 11 The primary results of the MOBILE trial confirmed the utility of CGM with alarms as an important behavior modification tool leading to a clinically meaningful reduction in HbA1c in patients with type 2 diabetes treated with basal insulin therapy. 21 In this analysis, we observed a large treatment effect among patients with baseline HbA1c values ≥10% for achieving both a greater than 1% reduction in HbA1c (42% adjusted difference vs. BGM, P = 0.02) and achieving HbA1c levels <8% (50% adjusted difference vs. BGM, P = 0.001).…”

“…The way CGM may influence glycemic control in patients not receiving intensive insulin therapy is multifaceted, with a potentially greater impact arising from improvements in glucose monitoring, medication adherence, lifestyle modifications, and health care provider interactions. 7–9 …”

“…There is limited evidence that CGM may improve glycemic control in patients with type 2 diabetes on variable treatment regimens, 7 , 8 , 10 , 11 although it is not clear which patients may experience the most treatment benefit from ongoing CGM therapy.…”

“… 20 There is emerging data suggesting that the use of CGM can improve glycemic control in patients with type 2 diabetes treated with less intensive insulin regimens or with noninsulin agents alone. 7 , 8 However, it is unknown if a greater treatment response in those with worse baseline glycemic control persists in these populations without the use of short or rapid acting insulin.…”

Recent Updates to Clinical Practice Guidelines for Diabetes Mellitus

“…The active use of CGM devices is now recommended from the early stage of diagnosis of diabetes requiring insulin management. In previous guidelines, CGM devices were only recommended for patients requiring multiple daily injections or continuous subcutaneous insulin infusion, but this year’s recommendation extends to long-acting insulin (basal insulin) users [ 43 , 44 ]. The use of CGM devices is also recommended for children with diabetes using insulin, and AID systems are recommended for children with type 1 diabetes.…”