Marked Improvement in A1C Levels After Initiation of Intermittently Scanned Continuous Glucose Monitoring Is Maintained Over 4 Years in Patients With Type 1 Diabetes

Abstract

Objective This study aimed to demonstrate the effectiveness of long-term use of intermittently scanned continuous glucose monitoring (isCGM) in adult patients with type 1 diabetes. Design and methods In this retrospective real-world study, 689 patients with type 1 diabetes who were >18 years of age and using isCGM were identified from the electronic patient records in North Karelia, Finland. A1C data were collected before and after the initiation of isCGM. The primary outcome was a change in the mean A1C over time after isCGM started. Results The greatest reductions in the mean A1C levels were observed 6 months (−0.54% [−5.9 mmol/mol], P <0.001) and 12 months (−0.42% [−4.6 mmol/mol] P <0.001) after the initiation of isCGM. Reduction in A1C remained significant for 4 years, although the mean reduction in A1C was −0.18% (−2.05 mmol/mol) (P = 0.009) at 48 months compared with baseline. In a subgroup analysis, patients with a baseline A1C >9% (75 mmol/mol) benefited the most from initiation of isCGM (reduction −0.97% [−10.6 mmol/mol], P <0.001 at 12 months and −0.92% [−10.1 mmol/mol], P <0.001 at 48 months). Neither sex nor age at the start of isCGM were correlated with A1C reduction. Conclusion Use of isCGM improves A1C levels significantly in adult patients with type 1 diabetes. Significant reduction in A1C persisted over 4 years of use, although the effect diminished over time.

The use of isCGM leads to marked reduction in severe hypoglycemia requiring emergency medical service or hospital admission and diabetic ketoacidosis in adult type 1 diabetes patients

“…In addition, our study demonstrated significant reductions in both severe hypoglycemia requiring EMS or hospital admission and hospitalizations for DKA after start of isCGM in a real-world setting. Also, the significant reduction of HbA1c is in line with previous RCTs [ 16 ] and real-world studies [ 7 , 14 , 17 ], as well as a recent meta-analysis [ 18 ], showing that isCGM is efficient in lowering HbA1c in patients with type 1 diabetes although our findings were modest compared to the findings from Evans et al (− 0.28% (− 3.1 mmol/mol) vs − 0.56% (− 6.1 mmol/mol)) [ 18 ] which may be due to the longer follow-up in our study.…”

“…FreeStyle Libre isCGM (later isCGM) was introduced to patients in 2016. From 2016 to 2020, Siun sote-funded isCGM was limited to type 1 diabetes patients fulfilling special criteria as described in our previous article [ 14 ]. These criteria included (1) suboptimal HbA1c despite optimized treatment with repeated hypoglycemic events, (2) planning to become or being pregnant, (3) fear of hypoglycemia, (4) fear of needles, leading to inability to perform SMBG, (5) end-stage renal disease and dialysis treatment, (6) inability to execute SMBG because of amputation or disability, and (7) difficulties in carrying out SMBG because of occupation.…”

Continuous glucose monitoring

“…Systematic review and meta-analysis data show that real-time CGM can improve glycaemic control, and can lead to longer periods in the target glucose range (known as “time in range”), reducing HbA 1c and reducing severe hypoglycaemia 67. Real world evidence suggests reduction in A 1c also occurs with isCGM 8…”

“…In the 2022 meta-analysis, real-time CGM alone had a small but statistically significant improvement in A 1c (mean difference (95% confidence interval) −0.22% −0.31 to −0.14, I 2 =79%) whereas isCGM showed no improvement in A 1c ,5 although real-world evidence suggests reduction in A 1c also occurs with isCGM 8…”

Association Between Adherence, A1C Improvement, and Type of Continuous Glucose Monitoring System in People with Type 1 Diabetes or Type 2 Diabetes Treated with Intensive Insulin Therapy

“…Use of CGM systems is associated with beneficial glycemic outcomes among people with T1D or T2D-IIT [ 3 – 5 ]. These glycemic outcomes are achieved through behavior change on behalf of the person with diabetes and careful adjustment and monitoring of their treatment regimen in consultation with a healthcare provider [ 6 ].…”