medwireNews: Discontinuing continuous glucose monitoring (CGM) leads to the loss of approximately half of the additional time in glycemic range (TIR) accrued during its use among people with type 2 diabetes, MOBILE study data show.
Roy Beck (Jaeb Center for Health Research, Tampa, Florida, USA) and co-investigators therefore say: “Continuation of CGM long term is necessary for the glycemic benefits to be sustained and ultimately contribute to risk reduction for long-term complications.”
The randomized MOBILE study initially revealed that 8 months of real-time CGM led to significantly greater reductions in glycated hemoglobin (HbA1c) and significantly more TIR than standard blood glucose monitoring in people with type 2 diabetes treated with basal without bolus insulin.
The current analysis focuses on a 6-month extension of the study, during which time half of the CGM group switched back to standard monitoring.
The researchers report that, at 14 months, the mean TIR was 50% among the 53 participants who discontinued CGM. This was a significant 12 percentage points lower than the 62% TIR observed at 8 months, but still higher than the baseline value of 38%.
“This worsening of TIR after discontinuing CGM is clinically relevant, as evidence is emerging that TIR is associated with the risk of diabetes-related complications in type 1 and type 2 diabetes,” Beck et al remark.
By comparison, mean TIR at baseline, 8, and 14 months was 44%, 56%, and 57%, respectively, among the 53 individuals who continued CGM, and 41%, 43%, and 45%, respectively, among the 57 participants who used standard monitoring throughout the study.
The adjusted treatment group difference in mean TIR between the groups that discontinued and continued CGM was a nonsignificant 6%.
Beck and team observed a similar pattern of results for HbA1c. In this case, mean HbA1c fell from 9.1% to 7.9% (76 to 63 mmol/mol) following the initiation of CGM, then increased again, to 8.2% (66 mmol/mol) 6 months after discontinuing CGM. In the group that continued CGM, the corresponding values were 9.1%, 8.2%, and 8.1% (65 mmol/mol), while for those in the standard monitoring group they were 9.0% (75 mmol/mol), 8.4% (68 mmol/mol), and 8.5% (69 mmol/mol).
The investigators note that “few glucose-lowering medications were added or discontinued and only minimal changes occurred in total daily insulin doses between months 8 and 14.”
They therefore believe that “the reduction in TIR […] after CGM discontinuation can be attributed mainly to behavioral changes triggered by the lack of CGM cues regarding glucose levels.”
“The fact that the drop in TIR after discontinuing CGM did not fully revert to levels before starting CGM suggests that there could be potential lasting benefits of the 8 months of CGM use possibly as a result of lifestyle and diet modifications or improved medication adherence,” the team concludes in Diabetes Care.
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Diabetes Care 2021; doi:10.2337/dc21-1304