Pediatric Medicaid Patients With Type 1 Diabetes Benefit From Continuous Glucose Monitor Technology

Background:We determined the uptake rate of continuous glucose monitors (CGMs) and examined associations of clinical and demographic characteristics with CGM use among patients with type 1 diabetes covered by Colorado Medicaid during the first two years of CGM coverage with no out-of-pocket cost.Method:We retrospectively reviewed data from 892 patients with type 1 diabetes insured by Colorado Medicaid (Colorado Health Program [CHP] and CHP+, Colorado Medicaid expansion). Demographics, insulin pump usage, CGM usage, and hemoglobin A1c (A1c) were extracted from the medical record. Data downloaded into CGM software at clinic appointments were reviewed to determine 30-day use prior to appointments. Subjects with some exposure to CGM were compared to subjects never exposed to CGM, and we examined the effect of CGM use on glycemic control.Results:Twenty percent of subjects had some exposure to CGM with a median of 22 [interquartile range 8, 29] days wear. Sixty one percent of CGM users had >85% sensor wear. Subjects using CGM were more likely to be younger (P < .001), have shorter diabetes duration (P < .001), and be non-Hispanic White (P < .001) than nonusers. After adjusting for age and diabetes duration, combined pump and CGM users had a lower A1c than those using neither technology (P = .006). Lower A1c was associated with greater CGM use (P = .002) and increased percent time in range (P < .001).Conclusion:Pediatric Medicaid patients successfully utilized CGM. Expansion of Medicaid coverage for CGM may help improve glycemic control and lessen disparities in clinical outcomes within this population.     

An Examination of the Glucose Management Indicator in Young Children with Type 1 Diabetes

Background:Previous studies utilizing glucose data from continuous glucose monitors (CGM) to estimate the Glucose Management Indicator (GMI) have not included young children or determined appropriate GMI formulas for young children with type 1 diabetes (T1D).Methods:We extracted CGM data for 215 children with T1D (0-6 years) from a repository. We defined sampling periods ranging from the 3-27 days prior to an HbA1c measurement and compared a previously established GMI formula to a young child-specific GMI equation based on the sample’s CGM data. We examined associations between HbA1c, GMI values, and other CGM metrics for each sampling period.Results:The young child-specific GMI formula and the published GMI formula did not evidence significant differences when using 21-27 days of CGM data. The young child-specific GMI formula demonstrated higher correlations to laboratory HbA1c when using 18 or fewer days of CGM data. Overall, the GMI estimate and HbA1c values demonstrate a strong relationship in young children with T1D.Conclusions:Future research studies may consider utilizing the young child-specific GMI formula if the data collection period for CGM values is under 18 days. Further, researchers and clinicians may consider changing the default number of days of data used to calculate glycemic metrics in order to maximize validity of CGM-derived metrics.     

Patient Controlled,Off-label Use of Continuous Glucose Monitoring: Real-World Medical Costs and Effects of Patient Controlled Sensor Augmented Pump Therapy in Adult Patients Type 1 Diabetes

Background:Continuous glucose monitoring (CGM) has shown promise to reduce glycated hemoglobin (HbA1c) levels, but its cost-effectiveness is seen as uncertain by reimbursement agencies. The aim of this study was to explore the impact of real-world, off-label, patient controlled CGM use in combination with continuous subcutaneous insulin infusion (CSII) on costs and effects in patients with type 1 diabetes in a Swedish clinic.Methods:A real-world, retrospective study with questionnaire on CGM use by adult patients with type 1 diabetes on CSII (Animas Vibe) were offered sensor augmented pump therapy (SAPT) (Dexcom G4) as part of hospital innovation funding program. Direct medical costs, HbA1c, and complications following switch from CSII with self-monitoring of blood glucose (SMBG) to SAPT were calculated.Results:Questionnaire data showed that CGM sensors were on average used 92% of the time for 22 days. One hundred and thirty-nine (95%) of 146 respondents used each sensor for longer than one week. Data analysis showed a statistically significant HbA1c decrease of 0.56% (6.1 mmol/mol) after change to SAPT. In patients using the sensor 100%, the decrease was 0.89% (9.8 mmol/mol). The analysis showed that SAPT led to higher costs (5500 USD/year) than CSII + SMBG (3680 USD/year), with incremental costs being 1815 USD per year to achieve an HbA1c decrease of 0.56% (6.1 mmol/mol). The incidence of all complications declined after switch to SAPT.Conclusion:The primary data analysis showed a decrease in HbA1c values following switch to SAPT, corresponding to previous cost-effectiveness studies, but at substantially lower costs due to longer sensor off-label use.     

Comparison Between One-Point Calibration and Two-Point Calibration Approaches in a Continuous Glucose Monitoring Algorithm

Background:The purpose of this study was to investigate the effect of using a 1-point calibration approach instead of a 2-point calibration approach on the accuracy of a continuous glucose monitoring (CGM) algorithm.Method:A previously published real-time CGM algorithm was compared with its updated version, which used a 1-point calibration instead of a 2-point calibration. In addition, the contribution of the corrective intercept (CI) to the calibration performance was assessed. Finally, the sensor background current was estimated real-time and retrospectively. The study was performed on 132 type 1 diabetes patients.Results:Replacing the 2-point calibration with the 1-point calibration improved the CGM accuracy, with the greatest improvement achieved in hypoglycemia (18.4% median absolute relative differences [MARD] in hypoglycemia for the 2-point calibration, and 12.1% MARD in hypoglycemia for the 1-point calibration). Using 1-point calibration increased the percentage of sensor readings in zone A+B of the Clarke error grid analysis (EGA) in the full glycemic range, and also enhanced hypoglycemia sensitivity. Exclusion of CI from calibration reduced hypoglycemia accuracy, while slightly increased euglycemia accuracy. Both real-time and retrospective estimation of the sensor background current suggest that the background current can be considered zero in the calibration of the SCGM1 sensor.Conclusions:The sensor readings calibrated with the 1-point calibration approach indicated to have higher accuracy than those calibrated with the 2-point calibration approach.     

Predictors of use and improvement in glycemic indices after initiating continuous glucose monitoring in real world: Data from Saudi Arabia

Background and aimsTo identify predictors of use and benefit from continuous glucose monitoring (CGM) in people with type 1 diabetes (T1D).MethodsPredictors of CGM use and changes in glycemic indices and other clinical parameters after initiating intermittently-scanned CGMs were examined in 116 individuals with T1D living in Saudi Arabia. Participants were categorized based on frequency of CGM sensor scanning at month 6 into: Frequent users (≥10 scans/day) and infrequent users (<10 scans/day).ResultsFrequent CGM users had an improvement in time in range (TIR) and time above range (TAR) at months 6 and 12; whereas infrequent users had comparable improvements but only at month 12. Individuals with baseline TIR <50% had a significant improvement in TIR and TAR; whereas those with baseline TIR ≥50% had a significant improvement only in time below range (TBR). Baseline TIR <50% and higher frequency of scans were predictive of improvement in TIR at month 6 (OR: 4.84, p <0.01, 1.05, p= 0.04; respectively); whereas baseline TBR was the only predictor of improvement in TBR (OR:1.24,p < 0.01). Being a woman, higher number of scans/day during the first 2 weeks of CGM use, and having a lower A1C at baseline predict being a frequent scanner at month 6 (OR: 2.81, p=0.04; 1.12, p <0.01; and 0.73, p <0.01; respectively).ConclusionsImprovement in glycemic control with CGM use can be predicted by: number of scans per day and baseline TIR and TBR in people with T1D.     

Effects of structured Ramadan Nutrition Plan on glycemic control and variability using continuous glucose monitoring in individuals with type 2 diabetes: A pilot study

Background and aimsContinuous glucose monitoring (CGM) has been increasingly used in recent years to evaluate glycemic control and variability in individuals with diabetes observing Ramadan fasting. However, the effectiveness of the Ramadan Nutrition Plan (RNP) in individuals with type 2 diabetes (T2D) using CGM-derived measures has not been investigated. The study aimed to evaluate the effects of structured RNP versus standard care using CGM in individuals with T2D.MethodsThis parallel non-randomized interventional study with patients’ preference design involved 21 individuals with T2D (mean age: 49 ± 10 years, BMI: 30.0 ± 6.2 kg/m²). Participants chose to receive either structured RNP (sRNT; structured Ramadan Nutrition Therapy group; n = 14) or standard care (SC; n = 7). Participants wore CGM 5 days before Ramadan and during Ramadan. CGM-derived measures of glycemic variability were calculated using Glyculator version 2.0.ResultsCompared to the SC group, the sRNT group significantly reduced their fasting blood glucose levels, HbA1c, total cholesterol, diastolic blood pressure, and increased dietary fiber intake. CGM data showed the sRNT group had significantly lower average sensor glucose, peak sensor value, estimated A1c, percentage and duration of time-above-range, J-index, mean amplitude of glycemic excursion (MAGE), and continuous overall net glycemic action (CONGA); and a significantly higher percentage of time-in-range (TIR).ConclusionsThe structured RNP significantly improved clinical outcomes, glycemic control and variability in individuals with T2D. The study highlights the importance of utilizing CGM sensor data to monitor glycemic excursions during Ramadan fasting. Adequately powered randomized controlled trials are needed to confirm the findings.     

The Accuracy of Continuous Glucose Monitoring in the Medical Intensive Care Unit

Objective:To assess the accuracy of continuous glucose monitoring (CGM) in medical intensive care unit (MICU) patients.Methods:A Medtronic Enlite^® sensor accuracy was assessed versus capillary blood glucose (CBG) and plasma glucose (PG) using the mean absolute relative difference (MARD), surveillance error grid (SEG) analysis and modified Bland-Altman plots.Results:Using CBG as a reference, MARD was 6.6%. Overall, 99.7% of the CGM readings were within the “no risk” zone. No significant differences in accuracy were seen within vasopressor subgroups. Using PG as the reference, MARD was 8.8%. The surveillance error grid analysis showed 95.2% of glucose readings were within the “no risk” zone. There were no device-related adverse events.Conclusion:The CGM sensor showed acceptable accuracy in MICU patients, regardless of vasopressor use.     

Perceived Burdens and Benefits Associated With Continuous Glucose Monitor Use in Type 1 Diabetes Across the Lifespan

Background:Continuous glucose monitors (CGMs) help people with type 1 diabetes (T1D) improve their glycemic profiles but are underutilized. To better understand why, perceived CGM burdens and benefits in nonusers versus users with type 1 diabetes across the lifespan were assessed.Methods:Burdens (BurCGM) and benefits of CGM (BenCGM) questionnaires were completed during T1D outpatient visits (n = 1334) from February 2019 to February 2020. Mean scores were calculated (scale one to five; higher scores reflect greater perceived burdens/benefits). Data were collected from medical records including glycated hemoglobin (HbA1c) within 3 months of the visit.Results:Individuals of all ages using CGM described more benefits and less burdens (mean scores 4.48 and 1.69, respectively) when compared with those who were not using CGM (mean score 4.19 and 2.35, respectively) (P < .001). There were no differences in burdens or benefits by sex. Non-CGM users aged ≥50 years had higher mean BurCGM scores than those aged <50 years (P = .004); the cost was the greatest barrier in those aged 27+ years. Other burdens were readings not trusted, painful to wear, and takes too much time to use. For those aged 65+, nonusers versus users, 18.5% versus 3.1% agreed with “it was too hard to understand CGM information,” and 21.4% versus 7.7% agreed that CGM causes too much worry. Mean HbA1C was lower in CGM users (8.1%) versus non-CGM users (mean A1c 9.1%; P < .001).Conclusions:CGM was perceived as having more burdens and less benefits in nonusers, with differences in concerns varying across the lifespan. Lower costs and age-appropriate education are needed to address these barriers.     

Continuous Glucose Monitoring Decreases Hypoglycemia Avoidance Behaviors,but Not Worry in Parents of Youth With New Onset Type 1 Diabetes

Background:Existing research shows that hypoglycemia fear (HF) is common in parents of children with established type 1 diabetes (T1D). We examined parental HF in the T1D recent-onset period and evaluated whether continuous glucose monitoring (CGM) adoption relates to improved outcomes of parental HF.Methods:In TACKLE-T1D, a prospective study of five- to nine-year olds with recent-onset T1D, parents completed the Hypoglycemia Fear Survey-Parents (HFS-P) at baseline (T1) and 6 (T2) and 12 (T3) months post-baseline. The HFS-P measures worry about hypoglycemia (HFS-Worry score) as well as hypoglycemia avoidance behaviors (HFS-Behavior score). We recorded CGM start dates for youth during the same time period through medical record review.Results:Between T1 and T2, 31 youth (32.3%) initiated CGM therapy, and between T2 and T3, an additional 17 youth (17.7%) began using CGM, leaving 48 youth who never initiated CGM therapy (50%) in the recent-onset period. Parents reported moderate HFS-Worry scores at T1 (32.9 ± 11.9), which increased between T1 and T2 (37.6 ± 11.4, P < .001) and plateaued between T2 and T3 (37.7 ± 12.4, P = .89). In contrast, parental HFS-Behavior scores decreased between T1 (33.1 ± 5.8) and T2 (32.2 ± 6.0, P = .005) and plateaued between T2 and T3 (32.2 ± 6.0, P = .95). Baseline HFS-Behavior and Worry scores were associated with increased adoption of CGM between T1-T2 and T2-T3, respectively. Parents of children initiating CGM therapy between T1 and T2 showed the largest decrease in HFS-Behavior (P = .03).Conclusions:Initiating CGM therapy within the first 12 months of T1D may help reduce parents’ use of hypoglycemia avoidance behaviors, but has little effect on parents’ hypoglycemia worry.     

Predictive Factors of the Adherence to Real-Time Continuous Glucose Monitoring Sensors: A Prospective Observational Study (PARCS STUDY)

Background:Information about factors related to better adherence to continuous glucose monitoring (CGM) sensor adherence is quite limited.Materials and Methods:Forty-six participants with type 1 diabetes using continuous subcutaneous insulin infusion (CSII) without CGM were recruited. The participants’ characteristics and diabetes-related quality of life (QOL) were evaluated at baseline and one year after starting to use CGM. Participants wearing the sensor for ≥60% of the time were considered as adherent.Results:The mean age of the 46 participants was 44.1 ± 15.0 years old and the mean glycohemoglobin (HbA1c) was 7.7 ± 1.0%; 60.9% of the participants were classified as adherent. The duration of using CSII was longer in the adherent group, and the degree of diabetic retinopathy was significantly different. There were no significant differences in age, frequency of self-monitoring of blood glucose, or Hypoglycemia Fear Survey (HFS-B for behavior, HFS-W for worry) score at baseline between the adherent and nonadherent groups. The Problem Areas in Diabetes (PAID) score at baseline was significantly higher and the total CSII-QOL score at baseline was significantly lower in the adherent group. The usage of dual-wave bolus was significantly increased in the adherent group (34.6%-61.5%, P = .016), but not in the nonadherent group (33.3%-33.3%, P > .999). The HbA1c level showed a significant improvement in the adherent group (7.8%-7.3%, P < .001), but not in the nonadherent group (7.5%-7.2%, P = .102).Conclusions:Higher adherence to CGM sensors may be associated with a heavier emotional burden of diabetes and a worse QOL in relation to CSII at baseline.     

Effect of Using Additional Readers for Flash Glucose Monitoring System on Metabolic Control,Safety, and the Incidence of Complications in Patients With Diabetes Mellitus

Background:The FreeStyle Libre is a flash glucose monitoring (FGM) system, and glucose levels are measured when the reader is brought to the sensor. Additional readers allow for the conversion into a continuous glucose monitoring (CGM) system. These transmitters read data from the sensor and send them to a bluetooth-enabled device thanks to which the user acquires glucose measurements automatically. This modification allows the patient to receive alerts when blood glucose values are abnormal.Methods:The study relied on the results of an anonymous online survey conducted among patients with diabetes or their caregivers who use Facebook groups. A total of 132 respondents who met certain criteria (diabetic who use FGM system longer than 3 months, at least 14 days per month) were enrolled in the study.Results:A significant decrease in self-reported glycated hemoglobin levels was found in adults and children using readers (variable: age P = .008; time P < .001), regardless of the age. The use of additional readers was associated with a significant decrease in the number of self-reported episodes of hypoglycemia (P < .001) and an improvement in the quality of life (based on self-reported limitations in everyday activities, social contacts, work/school, or doing sports).Conclusion:The use of additional readers for FGM system improves the metabolic control of diabetes and the quality of life, and has a positive effect on the safety of treatment. Flash glucose monitoring used together with additional readers operates as a CGM system and seems to be helpful for patients for the monitoring of interstitial levels of glucose; however, they should be careful when they use do it yourself solution.     

Exploring Parental Experiences of Using a Do-It-Yourself Solution for Continuous Glucose Monitoring Among Children and Adolescents With Type 1 Diabetes: A Qualitative Study

Background:MiaoMiao (MM) is a Bluetooth transmitter, which when paired with a smart phone/device, converts the Abbott FreeStyle Libre flash glucose monitoring system into a Do-It-Yourself (DIY) continuous glucose monitor (CGM). Families are increasingly adopting DIY CGM solutions, but little is known about parent and child experiences with these add-on technologies. We aimed to explore experiences of families using MM-CGM including challenges faced and their advice to others who may choose to use the technology.Methods:Between May and July 2019, we conducted 12 semistructured interviews (in person or via video conference) with parents of children (aged ≤16 years) with type 1 diabetes using MM-CGM. Interviews were audio recorded; professionally transcribed and key themes were identified through thematic analysis.Results:Overall, parents used MM-CGM to proactively manage their child’s blood glucose. In all participants, this led to a perceived decrease in frequency of hypoglycemia. Participants reported that the visibility and easy access to blood glucose readings, glucose trends, and customized alarms on parent’s phones decreased their disease burden and improved their sleep quality. Common barriers to using MM-CGM included difficulty of the setting up process, connectivity issues, and lack of support from medical teams.Conclusion:This study highlights the potential feasibility of using a DIY CGM system like MM-CGM, which could be an empowering and cost-effective tool for enabling remote monitoring of blood glucose in real time.     

Use of Personal Continuous Glucose Monitoring Device Is Associated With Reduced Risk of Hypoglycemia in a 16-Week Clinical Trial of People With Type 1 Diabetes Using Continuous Subcutaneous Insulin Infusion

Aims:Continuous glucose monitoring (CGM) has the potential to promote diabetes self-management at home with a better glycemic control as outcome. Investigation of the effect of CGM has typically been carried out based on randomized controlled trials with prespecified CGM devices on CGM-naïve participants. The aim of this study was to investigate the effect on glycemic control in people using their personal CGM before and during the trial.Materials and Methods:Data from the Onset 5 trial of 472 people with type 1 diabetes using either their personal CGM (n = 117) or no CGM (n = 355) and continuous subcutaneous insulin infusion in a 16-week treatment period were extracted. Change from baseline in glycated hemoglobin A1c (HbA_1c), number of hypoglycemic episodes, and CGM metrics at the end of treatment were analyzed with analysis of variance repeated-measures models.Results:Use of personal CGM compared with no CGM was associated with a reduction in risk of documented symptomatic hypoglycemia (event rate ratio: 0.82; 95% CI: 0.69-0.97) and asymptomatic hypoglycemia (event rate ratio: 0.72; 95% CI: 0.53-0.97), reduced time spent in hypoglycemia (P = .0070), and less glycemic variability (P = .0043) without a statistically significant increase in HbA_1c (P = .2028).Conclusions:Results indicate that use of personal CGM compared with no CGM in a population of type 1 diabetes is associated with a safer glycemic control without a statistically significantly deteriorated effect on HbA_1c, which adds to the evidence about the real-world use of CGM, where device type is not prespecified, and users are not CGM naïve.     

Diabetes Technology Experiences Among Latinx and Non-Latinx Youth with Type 1 Diabetes

Background:Diabetes technologies, such as insulin pumps and continuous glucose monitors (CGM), have been associated with improved glycemic control and increased quality of life for young people with type 1 diabetes (T1D); however, few young people use these devices, especially those from minority ethnic groups. Current literature predominantly focuses on white patients with private insurance and does not report experiences of diverse pediatric patients with limited resources.Methods:To explore potential differences between Latinx and non-Latinx patients, English- and Spanish-speaking young people with T1D (n = 173, ages 11-25 years) were surveyed to assess attitudes about and barriers to diabetes technologies using the Technology Use Attitudes and Barriers to Device Use questionnaires.Results:Both English- and Spanish-speaking participants who identified as Latinx were more likely to have public insurance (P = .0001). English-speaking Latinx participants reported higher Hemoglobin A1c values (P = .003), less CGM use (P = .002), and more negative attitudes about technology (generally, P = .003; and diabetes-specific, P < .001) than either non-Latinx or Spanish-speaking Latinx participants. Barriers were encountered with equivalent frequency across groups.Conclusions:Latinx English-speaking participants had less positive attitudes toward general and diabetes technology than Latinx Spanish-speaking and non-Latinx English-speaking peers, and differences in CGM use were associated with socioeconomic status. Additional work is needed to design and deliver diabetes interventions that are of interest to and supportive of patients from diverse ethnic and language backgrounds.     

Observed Characteristics Associated with Diabetes Device Use Among Teens with Type 1 Diabetes

Background:Despite advancements in diabetes technologies, disparities remain with respect to diabetes device use in youth with type 1 diabetes (T1D). We compared sociodemographic, diabetes, and psychosocial characteristics associated with device (pump and continuous glucose monitor [CGM]) use in 13- to 17-year-old teens with T1D.Materials/Methods:Data were derived from a multicenter clinical trial to optimize self-care and glycemic control in teens with T1D. We categorized teens as pump users versus non-users and CGM users versus non-users based on their diabetes device usage. Chi-square and t-tests compared characteristics according to device use.Results:The sample comprised 301 teens (50% female) with baseline mean ± SD age 15.0 ± 1.3 years, T1D duration 6.5 ± 3.7 years, and HbA1c 8.5 ± 1.1% (69 ± 12 mmol/mol). Two-thirds (65%) were pump users, and 27% were CGM users. Pump users and CGM users (vs. non-users) were more likely to have a family annual household income ≥$150,000, private health insurance, and a parent with a college education (all P < .001). Pump users and CGM users (vs. non-users) also performed more frequent daily blood glucose (BG) checks (both P < .001) and reported more diabetes self-care behaviors (both P < .05). Pump users were less likely to have baseline HbA1c ≥9% (75 mmol/mol) (P = .005) and to report fewer depressive symptoms (P = .02) than pump non-users. Parents of both CGM and pump users reported a higher quality of life in their youth (P < .05).Conclusion:There were many sociodemographic, diabetes-specific, and psychosocial factors associated with device use. Modifiable factors can serve as the target for clinical interventions; youth with non-modifiable factors can receive extra support to overcome potential barriers to device use.     

A Review of the First Long-term Implantable Continuous Glucose Monitoring System Available in the United States

Background:Although real-time continuous glucose monitoring (rtCGM) has been shown to improve glycemic control in patients with type 1 diabetes mellitus and type 2 diabetes mellitus treated with insulin, rates of adoption have been low. A novel approach, with the use of a long-term implantable continuous glucose monitoring (LTI CGM) has the potential to overcome barriers to rtCGM. The purpose of this review is to provide a background on the first LTI CGM technology to be approved, along with a review of contraindications, interference, safety, accuracy, and efficacy. Considerations for patient selection are discussed based on the available evidence.Methods:PubMed, EMBASE, and Cochrane Library were searched for keywords and subject headings to identify studies assessing LTI CGM.Results:Seven studies were identified which assessed LTI CGM. Mean absolute relative difference is similar to available CGM devices. Rates of adverse events were low. Change in hemoglobin A1c with LTI CGM may be comparable to rtCGM.Conclusions:Based on the available evidence, LTI CGM appears to be safe and accurate. Additional clinical trial investigation is warranted to evaluate the glycemic efficacy of LTI CGM.     

Time in Specific Glucose Ranges,Glucose Management Indicator,and Glycemic Variability: Impact of Continuous Glucose Monitoring (CGM) System Model and Sensor on CGM Metrics

Background:International consensus recommends a set of continuous glucose monitoring (CGM) metrics to assess quality of diabetes therapy. The impact of individual CGM sensors on these metrics has not been thoroughly studied yet. This post hoc analysis aimed at comparing time in specific glucose ranges, coefficient of variation (CV) of glucose concentrations, and glucose management indicator (GMI) between different CGM systems and different sensors of the same system.Method:A total of 20 subjects each wore two Dexcom G5 (G5) sensors and two FreeStyle Libre (FL) sensors for 14 days in parallel. Times in ranges, GMI, and CV were calculated for each 14-day sensor experiment, with up to four sensor experiments per subject. Pairwise differences between different sensors of the same CGM system as well as between sensors of different CGM system were calculated for these metrics.Results:Pairwise differences between sensors of the same model showed larger differences and larger variability for FL than for G5, with some subjects showing considerable differences between the two sensors. When pairwise differences between sensors of different CGM models were calculated, substantial differences were found in some subjects (75th percentiles of differences of time spent <70 mg/dL: 5.0%, time spent >180 mg/dL: 9.2%, and GMI: 0.42%).Conclusion:Relevant differences in CGM metrics between different models of CGM systems, and between different sensors of the same model, worn by the same study subjects were found. Such differences should be taken into consideration when these metrics are used in the treatment of diabetes.     

Effect of CGM in the HbA1c and Coefficient of Variation of glucose in a pediatric sample

Aim of the studyPrevious studies have found no significant improvements in glycated hemoglobin (HbA1c), while using Continuous Glucose Monitoring (CGM), with children and adolescents. The aim of this paper is to measure the change in HbA1c, and the Coefficient of Variation in glucose levels, when using CGM, once the effect of other relevant variables, such as gender, actual age, the years the patient has had diabetes, use of an insulin pump, the presence of autoimmune disease, other associated pathologies, and weekly hours of exercise, are controlled for.MethodsThis is a retrospective study that uses a linear regression model. Data was collected from Type 1 Diabetes Mellitus (T1DM), children diagnosed between 2003 and 2017 in the Pediatric Unit for Diabetes in Zaragoza, Spain. We used a linear regression and the method of estimation is Ordinary Least Squares.ResultsResults show that the use of CGM decreased the HbA1c value by 3.5% and the Coefficient of Variation by 14%.ConclusionsThe implication of these results is that this device helped in the management of diabetes, although more research is needed to distinguish between different devices in terms of their efficacy.     

Clinical Accuracy of a Continuous Glucose Monitoring System With an Advanced Algorithm

Background:

We assessed the performance of a modified Dexcom G4 Platinum system with an advanced algorithm, in comparison with frequent venous samples measured on a laboratory reference (YSI) during a clinic session and in comparison to self-monitored blood glucose (SMBG) during home use.

Methods:

Fifty-one subjects with diabetes were enrolled in a prospective multicenter study. Subjects wore 1 sensor for 7-day use and participated in one 12-hour in-clinic session on day 1, 4, or 7 to collect YSI reference venous glucose every 15 minutes and capillary SMBG test every 30 minutes. Carbohydrate consumption and insulin dosing and timing were manipulated to obtain data in low and high glucose ranges.

Results:

In comparison with the laboratory reference method (n = 2,263) the system provided a mean and median absolute relative differences (ARD) of 9.0% and 7.0%, respectively. The mean absolute difference for CGM was 6.4 mg/dL when the YSIs were within hypoglycemia ranges (≤ 70 mg/dL). The percentage in the clinically accurate Clarke error grid A zone was 92.4% and in the benign error B zone was 7.1%. Majority of the sensors (73%) had an aggregated MARD in reference to YSI ≤ 10%. The MARD of CGM-SMBG for home use was 11.3%.

Conclusions:

The study showed that the point and rate accuracy, clinical accuracy, reliability, and consistency over the duration of wear and across glycemic ranges were superior to current commercial real-time CGM systems. The performance of this CGM is reaching that of a self-monitoring blood glucose meter in real use environment.     

Multisite Study of an Implanted Continuous Glucose Sensor Over 90 Days in Patients With Diabetes Mellitus

Background:

Continuous glucose monitoring (CGM), which enables real-time glucose display and trend information as well as real-time alarms, can improve glycemic control and quality of life in patients with diabetes mellitus. Previous reports have described strategies to extend the useable lifetime of a single sensor from 1-2 weeks to 28 days. The present multisite study describes the characterization of a sensing platform achieving 90 days of continuous use for a single, fully implanted sensor.

Method:

The Senseonics CGM system is composed of a long-term implantable glucose sensor and a wearable smart transmitter. Study subjects underwent subcutaneous implantation of sensors in the upper arm. Eight-hour clinic sessions were performed every 14 days, during which sensor glucose values were compared against venous blood lab reference measurements collected every 15 minutes using mean absolute relative differences (MARDs).

Results:

All subjects (mean ± standard deviation age: 43.5 ± 11.0 years; with 10 sensors inserted in men and 14 in women) had type 1 diabetes mellitus. Most (22 of 24) sensors reported glucose values for the entire 90 days. The MARD value was 11.4 ± 2.7% (range, 8.1-19.5%) for reference glucose values between 40-400 mg/dl. There was no significant difference in MARD throughout the 90-day study (P = .31). No serious adverse events were noted.

Conclusions:

The Senseonics CGM, composed of an implantable sensor, external smart transmitter, and smartphone app, is the first system that uses a single sensor for continuous display of accurate glucose values for 3 months.