Estimating the cost-effectiveness of intermittently scanned continuous glucose monitoring in adults with type 1 diabetes in England

OBJECTIVE

We previously showed that intermittently scanned continuous glucose monitoring (isCGM) reduces HbA1c at 24 weeks compared with self-monitoring of blood glucose with finger pricking (SMBG) in adults with type 1 diabetes and high HbA1c levels (58-97 mmol/mol [7.5%-11%]). We aim to assess the economic impact of isCGM compared with SMBG.

METHODS

Participant-level baseline and follow-up health status (EQ-5D-5L) and within-trial healthcare resource-use data were collected. Quality-adjusted life-years (QALYs) were derived at 24 weeks, adjusting for baseline EQ-5D-5L. Participant-level costs were generated. Using the IQVIA CORE Diabetes Model, economic analysis was performed from the National Health Service perspective over a lifetime horizon, discounted at 3.5%.

RESULTS

Within-trial EQ-5D-5L showed non-significant adjusted incremental QALY gain of 0.006 (95% CI: -0.007 to 0.019) for isCGM compared with SMBG and an adjusted cost increase of £548 (95% CI: 381-714) per participant. The lifetime projected incremental cost (95% CI) of isCGM was £1954 (-5108 to 8904) with an incremental QALY (95% CI) gain of 0.436 (0.195-0.652) resulting in an incremental cost-per-QALY of £4477. In all subgroups, isCGM had an incremental cost-per-QALY better than £20,000 compared with SMBG; for people with baseline HbA1c >75 mmol/mol (9.0%), it was cost-saving. Sensitivity analysis suggested that isCGM remains cost-effective if its effectiveness lasts for at least 7 years.

CONCLUSION

While isCGM is associated with increased short-term costs, compared with SMBG, its benefits in lowering HbA1c will lead to sufficient long-term health-gains and cost-savings to justify costs, so long as the effect lasts into the medium term.

Comparing the glycaemic outcomes between real-time continuous glucose monitoring (rt-CGM) and intermittently scanned continuous glucose monitoring (isCGM) among adults and children with type 1 diabetes: A systematic review and meta-analysis of randomized controlled trials

AIM

To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the effectiveness of real-time continuous glucose monitoring (rtCGM) versus intermittently scanned continuous glucose monitoring (isCGM) on key glycaemic metrics (co-primary outcomes HbA1c and time-in-range [TIR] 70-180 mg/dL, 3.9-10.0 mmol/L) among people with type 1 diabetes (T1D).

METHODS

Medline, PubMed, Scopus, Web of Science and Cochrane Central Register of clinical trials were searched. Inclusion criteria were RCTs; T1D populations of any age and insulin regimen; comparing any type of rtCGM with isCGM (only the first generation had been compared to date); and reporting the glycaemic outcomes. Glycaemic outcomes were extracted post-intervention and expressed as mean differences and 95% CIs between the two comparators. Results were pooled using a random-effect meta-analysis. The risk of bias was assessed using the Cochrane RoB2 tool. The quality of evidence was assessed by the GRADE approach.

RESULTS

Five RCTs met the inclusion criteria (4 parallel and 1 crossover design; 4 with CGM use <8 weeks), involving 446 participants (354 adults; 92 children and adolescents). Overall, meta-analysis showed rtCGM compared to isCGM improved absolute TIR by +7.0% (95% CI: 5.8%-8.3%, I2  = 0%, p < 0.01) accompanied by a favorable effect on time-below-range <70 mg/dL (3.9 mmol/L) - 1.7% (95%CI: -3.0% to -0.4%; p = 0.03). No differences were seen regarding HbA1c.

CONCLUSIONS

This meta-analysis highlights that for people with T1D, rtCGM confers benefits over isCGM primarily related to increased TIR, with improvements in hypo- and hyperglycaemia.

A Case Report of Diabetes in a Patient with Glycogen Storage Disease Type 1a

Glycogen storage disease type 1a (GSD-1a) is a rare congenital disease. Recently, life expectancy with GSD-1a has been improved by its early diagnosis and management. Complications of diabetes with GSD-1a are extremely rare. The optimal treatment for glucose control using this disease combination remains unclear. The existence of GSD-1a and diabetes can cause both hypoglycemia and hyperglycemia, making glucose control especially problematic. In the present report, α-glucosidase inhibitor (α-GI) and dipeptidyl peptidase-4 (DPP-4) inhibitors improved hyperglycemia without symptoms of hypoglycemia in a patient with diabetes and GSD-1a using intermittent continuous glucose monitoring (isCGM).

Personalizing the Use of a Intermittently Scanned Continuous Glucose Monitoring Device in Individuals With Type 1 Diabetes: A Cost-Effectiveness Perspective in the Netherlands (FLARE-NL 9)

AIMS

Intermittently scanned continuous glucose monitoring (isCGM) is a method to monitor glucose concentrations without using a finger prick. Among persons with type 1 diabetes (T1D), isCGM results in improved glycemic control, less disease burden and improved health-related quality of life (HRQoL). However, it is not clear for which subgroups of patients isCGM is cost-effective. We aimed to provide a real-world cost-effectiveness perspective.

METHODS

We used clinical data from a 1-year nationwide Dutch prospective observational study (N = 381) and linked these to insurance records. Health-related quality of life was assessed with the EQ-5D-3L questionnaire. Individuals were categorized into 4 subgroups: (1) frequent hypoglycemic events (58%), (2) HbA1c > 70 mmol/mol (8.5%) (19%), (3) occupation that requires avoiding finger pricks and/or hypoglycemia (5%), and (4) multiple indications (18%). Comparing costs and outcomes 12 months before and after isCGM initiation, incremental cost-effectiveness ratios (ICERs) were calculated for the total cohort and each subgroup from a societal perspective (including healthcare and productivity loss costs) at the willingness to pay of €50,000 per quality-adjusted life year (QALY) gained.

RESULTS

From a societal perspective, isCGM was dominant in all subgroups (ie higher HRQoL gain with lower costs) except for subgroup 1. From a healthcare payer perspective, the probabilities of isCGM being cost-effective were 16%, 9%, 30%, 98%, and 65% for the total cohort and subgroup 1, 2, 3, and 4, respectively. Most sensitivity analyses confirmed these findings.

CONCLUSIONS

Comparing subgroups of isCGM users allows to prioritize them based on cost-effectiveness. The most cost-effective subgroup was occupation-related indications, followed by multiple indications, high HbA1c and the frequent hypoglycemic events subgroups. However, controlled studies with larger sample size are needed to draw definitive conclusions.

Two Cases With Type 1 Diabetes Treated With Insulin Pump Therapy Using a Telemedicine Approach During the COVID-19 Pandemic

Type 1 diabetes mellitus (T1D) is an autoimmune-related disease resulting in insulin dependency, treated with insulin injection via pen devices or continuous subcutaneous insulin infusion (CSII). Face-to-face instruction for managing insulin injection and dosing and machine-to-device troubleshooting are required early to initiate CSII from insulin injections. Thus, T1D individuals may encounter significant barriers to pen devices or CSII introduction if they live in remote rural areas. In this regard, intermittently scanned continuous glucose monitoring (isCGM) can share visualized glucose profiles via a cloud-platform-based system, offering the potential as an effective tool in telemedicine. Herewith, we report two cases of subjects with T1D living in remote rural areas whose CSII was safely introduced in outpatient settings with the aid of cloud-platform-based isCGM and a video-meeting tool. They showed improved glucose profiles after CSII initiation. Even under the coronavirus disease 2019 (COVID-19) pandemic, the telemedicine system enabled healthcare providers to monitor glucose profiles and confirm device procedures of CSII. We emphasize the usefulness of online instruction with cloud-platform-based isCGM for introducing CSII in cases with barriers to healthcare access, particularly during the COVID-19 pandemic.

"Empowering Us": A Community-Led Survey of Real-World Perspectives of Adults with Type 1 Diabetes Using Insulin Pumps and Continuous Glucose Monitoring to Manage Their Glucose Levels

OBJECTIVE

To conduct an Australian community-led survey of adults with type 1 diabetes (T1D), identifying priorities for, and barriers to, optimal use of advanced glucose management technologies.

RESEARCH DESIGN AND METHODS

A 30-question online survey of current or past users of insulin pump therapy (IPT), real-time continuous glucose monitoring (RT-CGM), or intermittently scanned CGM (isCGM) explored perceptions regarding device design, access, education, outcomes, and support.

RESULTS

Between November 2021 and January 2022, surveys were completed by 3,380 participants (age [mean±SD] 45±16 years; 62% female; 20±14 years diabetes), with 55%, 82%, and 55% reporting experience with IPT, RT-CGM, and isCGM, respectively. Overall, most considered diabetes technology '(extremely) important' for maintaining target glucose levels (98%) and reducing hypoglycaemia severity and frequency (93%). For most, technology contributed positively to emotional well-being (IPT 89%; RT-CGM 91%; isCGM 87%), which was associated with device effectiveness in maintaining glucose in range, comfort, and convenience. Barriers included affordability (IPT 68%; RT-CGM 81%; isCGM 69%) and insufficient information for informed choices about device suitability (IPT 39%; RT-CGM 41%; isCGM 36%).

CONCLUSIONS

Technology is perceived by adults with T1D as important for managing glycaemia and emotional well-being. Modifiable barriers to use include affordability, and information regarding device suitability.

Real-life 24-week changes in glycemic parameters among European users of flash glucose monitoring with type 1 and 2 diabetes and different levels of glycemic control

AIM

To evaluate real-life changes of glycemic parameters among flash glucose monitoring (FLASH) users who do not meet glycemic targets.

METHODS

De-identified data were obtained between 2014 and 2021 from patients using FLASH uninterrupted for a 24-week period. Glycemic parameters during first and last sensor use were examined in four identifiable groups: type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM) on basal-bolus insulin, T2DM on basal insulin, and T2DM without insulin treatment. Within each group, subgroup analyses were performed in persons with initial suboptimal glycemic regulation (time in range (TIR; 3.9-10 mmol/L) <70%, time above range (TAR; >10 mmol/L) >25%, or time below range (TBR; <3.9 mmol/L) >4%).

RESULTS

Data were obtained from 1,909 persons with T1DM and 1,813 persons with T2DM (1,499 basal-bolus insulin, 189 basal insulin, and 125 non-insulin users). In most of the performed analyses, both overall and in the various subgroups, significant improvements were observed in virtually all predefined primary (TIR) and secondary endpoints (eHbA1c, TAR, TBR and glucose variability).

CONCLUSIONS

24-weeks FLASH use in real life by persons with T1DM and T2DM with suboptimal glycemic regulation is associated with improvement of glycemic parameters, irrespective of pre-use regulation or treatment modality.

The Frequency of Intermittently Scanned Glucose and Diurnal Variation of Glycemic Metrics

BACKGROUND

The relation between the frequency of intermittently scanned continuous glucose monitoring (isCGM) and diurnal variation of time in range (TIR) and time below range (TBR) is unknown.

METHOD

A total of 163 persons with type 1 diabetes who used isCGM had glucose data for 60 days downloaded. Mean TIR and median TBR were calculated for 15-minute periods and presented for daytime and nighttime. The values for tertiles of scanning frequency were compared.

RESULTS

The 1st tertile (n = 53) of the population scanned <10 times; the 2nd tertile (n = 56) 10-13 times, and the 3rd tertile (n = 54) >13 per 24 hours. TIR (%, mean ± (SD)) increased significantly from the 1st to the 3rd scan tertile both during the day (43.8 ± 14.8, 52.0 ± 12.3, 62.1 ± 12.8) and the night (44.5 ± 17.3, 52.3 ± 18.5, 64.0 ± 13.9; P < .0001). In contrast, TBR (median, (IQR)) was not significantly associated with scan tertiles during daytime (3.5% (1.1-7.8), 4.4% (1.8-6.1), 3.5% (2.1-6.1); P = .85) or nighttime (3.8% (1.4-13.7), 5.0% (1.6-9.6), 5.7% (3.6-10.9); P = .24). In a multiple regression model, a 50% increase in 24-hour scanning frequency was associated with a 7.8 percentage point increase in TIR (95% CI, 5.6-10.0).

CONCLUSIONS

Increased scanning frequency was associated with a higher TIR both during daytime and nighttime with no change in TBR.

Intermittently scanned continuous glucose monitoring is associated with lower spontaneous abortion rate compared with conventional blood glucose monitoring in pregnant women with type 1 diabetes: An observational study

AIM

The objective of the present real-life study in France was to assess and compare characteristics and outcomes in a cohort of pregnant women with type 1 diabetes (T1D) using intermittently scanned continuous glucose monitoring (isCGM) or conventional blood glucose monitoring (BGM).

MATERIAL AND METHODS

We performed an observational study of a cohort of 153 women with T1D: 77 women were using isCGM, and 76 were using BGM. We compared the groups' maternal characteristics and maternal-fetal complications. The level of HbA1c was measured before pregnancy and then four times (after 8-12, 24-28, 30-33, and 35-37 weeks of gestation).

RESULTS

The two groups were similar in terms of age, prepregnancy BMI, diabetes duration, and diabetic vascular complications. There were no significant intergroup differences in the obstetric history. The spontaneous abortion rate was lower in the isCGM group than in the blood glucose monitoring group (5.3% vs. 20%, respectively; p = .0129), while the prepregnancy and first-trimester HbA1c levels were similar. There were no significant intergroup differences in the incidence of other maternal-fetal complications.

CONCLUSIONS

This observational study demonstrates that isCGM use is associated with lower spontaneous abortion compared with conventional BGM. Large prospective studies are needed to corroborate our findings and fully understand the relationship between glucose data at the time of conception/early pregnancy and foetal outcome.

The Impact of Baseline User Characteristics on the Benefits of Real-Time Versus Intermittently Scanned Continuous Glucose Monitoring in Adults With Type 1 Diabetes: Moderator Analyses of the ALERTT1 Trial

BACKGROUND

ALERTT1 showed that switching from intermittently scanned continuous glucose monitoring (isCGM) without alerts to real-time CGM (rtCGM) with alert functionality improved time in range (TIR; 70-180 mg/dL), glycated hemoglobin (HbA1c), time <54 mg/dL, and Hypoglycemia Fear Survey version II worry subscale (HFS-worry) score after six months in adults with type 1 diabetes (T1D). Moderator analyses aimed to identify certain subgroups that would benefit more from switching to rtCGM than others.

METHODS

Post hoc analyses of ALERTT1 evaluated the impact of 14 baseline characteristics on the difference (delta) in mean TIR, HbA1c, time <54 mg/dL, and HFS-worry score at six months between rtCGM and isCGM. Therefore, the delta was allowed to depend on each of these variables by including interactions in the moderator analysis model. Analyses were performed separately for each variable; variables with P < .10 in the univariable analysis were combined into a single model.

RESULTS

Univariable analyses showed no dependency of delta TIR, HbA1c, or time <54 mg/dL on variables other than CGM type. Only delta HFS-worry score depended on baseline HbA1c (P = .0059), indicating less worries with rtCGM in people with baseline HbA1c <6.5% or ≥8%. Given P < .10 for dependency of delta TIR on insulin therapy type (favoring multiple daily injections), baseline HbA1c, and baseline TIR, these variables were combined into a multivariable analysis; interactions were not statistically significant.

CONCLUSIONS

Except for HFS-worry score, no interactions between 14 baseline characteristics and the six-month intervention effect of rtCGM on TIR, HbA1c, or time <54 mg/dL were observed, supporting the conclusion of ALERTT1 that switching from isCGM without alerts to rtCGM with alert functionality is beneficial for a wide range of people with T1D.

Glycemic Metrics Derived From Intermittently Scanned Continuous Glucose Monitoring

BACKGROUND

Glucose data from intermittently scanned continuous glucose monitoring (isCGM) is a combination of scanned and imported glucose values. The present knowledge of glycemic metrics originate mostly from glucose data from real-time CGM sampled every five minutes with a lack of information derived from isCGM.

METHODS

Glucose data obtained with isCGM and hemoglobin A1c (HbA1c) were obtained from 169 patients with type 1 diabetes. Sixty-one patients had two observations with an interval of more than three months.

RESULTS

The best regression line of HbA1c against mean glucose was observed from 60 days prior to HbA_1c measurement as compared to 14, 30, and 90 days. The difference between HbA1c and estimated HbA1c (=glucose management indicator [GMI]) first observed correlated with the second observation (R2 0.61, P < .001). Time in range (TIR, glucose between 3.9 and 10 mmol/L) was significantly related to GMI (R2 0.87, P < .001). A TIR of 70% corresponded to a GMI of 6.8% (95% confidence interval, 6.3-7.4). The fraction of patients with the optimal combination of TIR >70% and time below range (TBR) <4% was 3.6%. The fraction of patients with TBR>4% was four times higher for those with high glycemic variability (coefficient of variation [CV] >36%) than for those with lower CV.

CONCLUSION

The individual difference between HbA1c and GMI was reproducible. High glycemic variability was related to increased TBR. A combination of TIR and TBR is suggested as a new composite quality indicator.

Benefits of a Switch from Intermittently Scanned Continuous Glucose Monitoring (isCGM) to Real-Time (rt) CGM in Diabetes Type 1 Suboptimal Controlled Patients in Real-Life: A One-Year Prospective Study §

The switch from intermittently scanned continuous glucose monitoring (isCGM) to real-time (rt) CGM could improve glycemic management in suboptimal controlled type 1 diabetes patients, but long-term study is lacking. We evaluated retrospectively the ambulatory glucose profile (AGP) in such patients after switching from Free Style Libre 1 (FSL1) to Dexcom G4 (DG4) biosensors over 1 year. Patients (n = 21, 43 ± 15 years, BMI 25 ± 5, HbA1c 8.1 ± 1.0%) had severe hypoglycemia and/or HbA1c ≥ 8%. AGP metrics (time-in-range (TIR) 70–180 mg/dL, time-below-range (TBR) <70 mg/dL or <54 mg/dL, glucose coefficient of variation (%CV), time-above-range (TAR) >180 mg/dL or >250 mg/dL, glucose management indicator (GMI), average glucose) were collected the last 3 months of FSL1 use (M0) and of DG4 for 3, 6 (M6) and 12 (M12) months of use. Values were means ± standard deviation or medians [Q1;Q3]. At M12 versus M0, the higher TIR (50 ± 17 vs. 45 ± 16, p = 0.036), and lower TBR < 70 mg/dL (2.5 [1.6;5.5] vs. 7.0 [4.5;12.5], p = 0.0007), TBR < 54 mg/dL (0.7 [0.4;0.8] vs. 2.3 [0.8;7.0], p = 0.007) and %CV (39 ± 5 vs. 45 ± 8, p = 0.0009), evidenced a long-term effectiveness of the switch. Compared to M6, TBR < 70 mg/dL decreased, %CV remained stable, while the improvement on hyperglycemia exposure decreased (higher GMI, TAR and average glucose). This switch was a relevant therapeutic option, though a loss of benefit on hyperglycemia stressed the need for optimized management of threshold alarms. Nevertheless, few patients attained the recommended values for AGP metrics, and the reasons why some patients are “responders” vs. “non-responders” warrant to be investigated.

Diabetes Knowledge and Metabolic Control in Type 1 Diabetes Starting With Continuous Glucose Monitoring: FUTURE-PEAK

PURPOSE

To investigate whether diabetes knowledge and health literacy impact glycemic control after 1 year of intermittently scanned continuous glucose monitoring (isCGM) in people with type 1 diabetes  ≥ 16 years.

METHODS

In this prospective real-world cohort study, we assessed diabetes knowledge using a new 10-item questionnaire [Patient Education and Knowledge (PEAK)] and health literacy using the validated 6-item Newest-Vital Sign-D (NVS-D) questionnaire. Primary endpoint was association between PEAK score and change in hemoglobin A1c (HbA1c). Secondary endpoints were link between NVS-D score and change in HbA1c and that between time spent in/above/below range and PEAK/NVS-D scores.

RESULTS

851 subjects were consecutively recruited between July 2016 and July 2018. Median PEAK score was 8 (range: 0-10), and median NVS-D score was 6 (range 0-6). HbA1c evolved from 7.9% (7.8%-8.0%), 63 (62-64) mmol/mol, at start to 7.7% (7.6%-7.7%), 61 (60-61) mmol/mol (P < 0.001), at 6 months and to 7.8% (7.7%-7.9%), 62 (61-63) mmol/mol, at 12 months (P < 0.001). HbA1c only improved in subgroups with higher scores [PEAK subgroups with score 7-8 (P = 0.005) and 9-10 (P < 0.001) and NVS-D score 4-6 (P < 0.001)]. At 12 months, time spent below 70 mg/dL was reduced by 15% (P < 0.001), and time spent below 54 mg/dL was reduced by 14% (P < 0.001), irrespective of PEAK/NVS-D score. Multiple linear regression analysis demonstrated an association of PEAK score, scan frequency, and baseline HbA1c with evolutions in time in range and time in hyperglycemia.

CONCLUSIONS

isCGM reduced time in hypoglycemia, and HbA1c evolved favorably. Our findings suggest that diabetes and health literacy affect glucometrics, emphasizing the importance of education.

Intermittently scanned continuous glucose monitoring is associated with high satisfaction but increased HbA1c and weight in well-controlled youth with type 1 diabetes

OBJECTIVE

We undertook a 24-month prospective observational single-center real-world trial to study impact of access to intermittently scanned continuous glucose monitoring (isCGM) on quality of life (QOL) and glycemic control of youth with type 1 diabetes (T1D).

METHODS

Between September 2016 and November 2017, 138 children and adolescents with T1D were recruited. Demographic, metabolic, and QOL data were collected during 24 months of routine follow-up. Primary endpoint was the evolution of QOL, with secondary outcomes change in HbA1c, occurrence of acute diabetes complications, and school absenteeism.

RESULTS

Ninety-two percent of participants found isCGM more user-friendly than capillary finger-stick tests and had high treatment satisfaction, without change in diabetes-specific QOL. HbA1c significantly increased from 7.2% (7.0-7.3) (55 mmol/mol [53-56]) at baseline to 7.6% (7.4-7.8) (60 mmol/mol [57-62]) at 12 months (P < .0001) and was unchanged up to 24 months. Overall increase was mainly driven by children with baseline HbA1c <7.0% (<53 mmol/mol). Additionally, BMI adjusted for age was higher at study end. In year before isCGM, 228 days per 100 patient-years of school absenteeism were reported, which dramatically decreased to 13 days per 100 patient-years (P = .016) after 24 months. Parents of children also reported less work absenteeism (P = .011).

CONCLUSION

The use of isCGM by T1D pediatrics is associated with high treatment satisfaction and fewer days of school absence. However, increased HbA1c and weight may reflect a looser lifestyle, with less attention to diet and more avoidance of hypoglycemia. Intensive education specifically focusing on these points may mitigate these issues.

Effects of unrestricted access to flash glucose monitoring in type 1 diabetes

AIMS

We assessed adherence and long-term effects on HbA1c of unrestricted access to flash glucose monitoring (FGM) in a single diabetes centre.

METHODS

In this observational study, we reviewed data files for all 411 patients with type 1 diabetes attending our clinic during a 2-year period. Adherence was reported in those who initiated FGM in our clinic (n = 321). Baseline and final HbA1c were noted for patients who continued FGM for more than 6 months without clinical conditions or interventions at baseline that could interfere with the effect of FGM on glycaemic control (n = 270).

RESULTS

After 2 years, the fraction of patients using FGM increased from 3% to 72%. Adherence to FGM was 88%. Baseline and final HbA1c was median (interquartile range) 63 mmol/mol (56, 74) (7.9% (7.3, 8.9)) and 59 mmol/mol (53, 68) (7.6% (7.0, 8.4)), respectively. The estimated difference final-baseline HbA1c was -4 mmol/mol (95% CI -5, -3) (-0.4% (-0.5, -0.3)) (P < .001). No significant difference was seen for patients with baseline HbA1c ≤ 7% (53 mmol/mol). The interval from initiation of FGM to final HbA1c was median 562 days (IQR 417, 662). The number of scans/day was median 11 (IQR 8, 13) and correlated negatively with both final and baseline HbA1c but not with change in HbA1c.

CONCLUSIONS

Following the introduction of unlimited access, nearly three quarters of the patients were FGM users. Long-term adherence was good, and HbA1c improved in all patients except in those with optimal glycaemic control at baseline.

Glycemic Variability and Hypoglycemic Excursions With Continuous Glucose Monitoring Compared to Intermittently Scanned Continuous Glucose Monitoring in Adults With Highest Risk Type 1 Diabetes

BACKGROUND

The I-HART CGM study has shown that real-time continuous glucose monitoring (rtCGM) has greater beneficial impact on hypoglycemia than intermittently scanned continuous glucose monitoring (iscCGM) in adults with type 1 diabetes at high risk (Gold score ≥4 or recent severe hypoglycemia using insulin injections). In this subanalysis, we present the impact of rtCGM and iscCGM on glycemic variability (GV).

METHODS

Forty participants were recruited to this parallel group study. Following two weeks of blinded rtCGM (DexcomG4), participants were randomized to rtCGM (Dexcom G5; n = 20) or iscCGM (Freestyle Libre; n = 20) for eight weeks. An open-extension phase enabled participants on rtCGM to continue for a further eight weeks and those on iscCGM to switch to rtCGM over this period. Glycemic variability measures at baseline, 8- and 16-week endpoints were compared between groups.

RESULTS

At the eight-week endpoint, between-group differences demonstrated significant reduction in several GV measures with rtCGM compared to iscCGM (GRADE%hypoglycemia, index of glycemic control [IGC], and average daily risk range [ADRR]; P < .05). Intermittently scanned continuous glucose monitoring reduced mean average glucose and glycemic variability percentage and GRADE%hyperglycemia compared with rtCGM (P < .05). At 16 weeks, the iscCGM group switching to rtCGM showed significant improvement in GRADE%hypoglycemia, personal glycemic status, IGC, and ADRR.

CONCLUSION

Our data suggest most, but not all, GV measures improve with rtCGM compared with iscCGM, particularly those measures associated with the risk of hypoglycemia. Selecting appropriate glucose monitoring technology to address GV in this high-risk cohort is important to minimize the risk of glucose extremes and severe hypoglycemia.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT03028220.

Non-adjunctive flash glucose monitoring system use during summer-camp in children with type 1 diabetes: The free-summer study

BACKGROUND

A factory-calibrated sensor for intermittently scanned continuous glucose monitoring (isCGM) is accurate and safe in children with type 1 diabetes (T1D). Data on isCGM effectiveness as a replacement for self-monitoring of blood glucose (SMBG) in this population is scarce.

OBJECTIVE

The aim of this study was to evaluate the non-adjunctive use of isCGM in children with T1D during 2 weeks in a challenging summer-camp setting.

METHODS

In this two-arm, parallel, randomized, outpatient clinical trial we enrolled 46 children (25 females, mean ± SD: age 11.1 ± 2.6 years, glycated hemoglobin (HbA1c) 7.4% ± 0.7%): 26 in the isCGM group were blinded for the SMBG and insulin dosing was isCGM-based, whereas 20 in the control group were blinded for isCGM and performed SMBG-based insulin dosing. The primary outcome of intention-to-treat analysis was between-group difference in the proportion of time within range 3.9 to 10 mmol/L (TIR).

RESULTS

There was no significant difference in TIR (3.9-10 mmol/L) between the two groups. In participants with suboptimal metabolic control (HbA1c > 7%) we observed a significant reduction in time spent above 10 mmol/L (P < 0.05) and an improvement in TIR (P = 0.05) in the isCGM group. No severe hypoglycemic events or serious adverse events occurred. Overall mean absolute relative difference (MARD) between isCGM and SMBG was 18.3%, with median absolute relative difference (ARD) of 8%. Consensus error grid analysis demonstrated 82.2% and 95.2% of results in zone A, and zone A + B, respectively.

CONCLUSION

The non-adjunctive use of isCGM was as safe and effective as SMBG, and reduced time spent in hyperglycemia in a sub-population of children with T1D with suboptimal glycemic control.

TRIAL REGISTRATION

NCT03182842.