Effect on glycemic control by short- and long-term use of continuous glucose monitoring in clinical practice

An overview of advancements in closed-loop artificial pancreas system

Type 1 diabetes (T1D) is one of the world's health problems with a prevalence of 1.1 million for children and young adults under the age of 20. T1D is a health problem characterized by autoimmunity and the destruction of pancreatic cells that produce insulin. The available treatment is to maintain blood glucose within the desired normal range. To meet bolus and basal requirements, T1D patients may receive multiple daily injections (MDI) of fast-acting and long-acting insulin once or twice daily. In addition, insulin pumps can deliver multiple doses a day without causing injection discomfort in individuals with T1D. T1D patients have also monitored their blood glucose levels along with insulin replacement treatment using a continuous glucose monitor (CGM). However, this CGM has some drawbacks, like the sensor needs to be replaced after being inserted under the skin for seven days and needs to be calibrated (for some CGMs). The treatments and monitoring devices mentioned creating a lot of workloads to maintain blood glucose levels in individuals with T1D. Therefore, to overcome these problems, closed-loop artificial pancreas (APD) devices are widely used to manage blood glucose in T1D patients. Closed-loop APD consists of a glucose sensor, an insulin infusion device, and a control algorithm. This study reviews the progress of closed-loop artificial pancreas systems from the perspective of device properties, uses, testing procedures, regulations, and current market conditions.

Factors influencing the effectiveness of using flash glucose monitoring on glycemic control for type 1 diabetes in Saudi Arabia

BACKGROUND

In 2017, 35000 Saudi children and adolescents were living with a type 1 diabetes (T1D) diagnosis. Diabetic complications are minimized upon strengthened glycemic regulation. The annual cost of treating diabetic patients with complications was four-fold higher than for patients without complications. The use of flash glucose monitoring (FGM) enables better diabetes treatment and thereby improves glycemic control. Understanding the factors that affect effectiveness of FGM will help enhance the device’s use and management of hospital resources, resulting in improved outcomes.

AIM

To investigate factors that affect effectiveness of the FGM system for glycated hemoglobin (HbA1c) levels/glycemic control among T1D patients.

METHODS

A retrospective empirical analysis of T1D patient records from King Abdul-Aziz University Hospital and Prince Sultan Military Medical City was performed. T1D patients who began FGM between 2017 and 2019 were included.

RESULTS

The data included 195 T1D patients (70 males and 125 females) with a mean age of 23.6 ± 8.1 years. Among them, 152 patients used multiple daily injection and 43 used an insulin pump. The difference in HbA1c level from baseline and after using FGM was -0.60 ± 2.10, with a maximum of 4.70 and a minimum of -6.30. There was a statistically significant negative correlation between the independent variables (age, duration of diabetes, level of engagement) and HbA1c. The group with the highest HbA1c mean (9.85) was 18-years-old, while the group with the lowest HbA1c mean (7.87) was 45-years-old. Patients with a low level of engagement (less than six scans per day) had the highest HbA1c mean (9.84), whereas those with a high level of engagement (more than eight scans per day) had the lowest HbA1c mean (8.33).

CONCLUSION

With proper education, FGM can help people with uncontrolled T1D over the age of 18 years to control their glucose level.

Healthcare Resource Waste Associated with Patient Nonadherence and Early Discontinuation of Traditional Continuous Glucose Monitoring in Real-World Settings: A Multicountry Analysis

BACKGROUND

Traditional continuous glucose monitoring (CGM) provides detailed information on glucose patterns and trends to inform daily diabetes management decisions, which is particularly beneficial for patients with a history of hypoglycemia unawareness. However, a high level of patient adherence (≥70%) is required to achieve clinical benefits. The aim of this study was to assess the impact of real-world patient nonadherence and early discontinuation on healthcare resource use.

METHODS

A cost calculator was designed to evaluate monthly healthcare resource waste within the first year of traditional CGM initiation by combining estimates of real-world nonadherence and early discontinuation from the literature with the wholesale acquisition costs of the current technology in the United States (for a commercial payer and for Medicare), or its equivalent in Sweden, Germany, or the Netherlands.

RESULTS

Based on an early discontinuation rate of 27% and nonadherence rates of 13.9%-31.1% over the 12 months following initiation, the healthcare resource waste associated with nonadherence and early discontinuation was $220,289 and $21,775, respectively, for every 100 patients initiating CGM in the U.S. commercial payer scenario. In the Medicare scenario, the corresponding figures were $72,648 and $5,675, respectively. In both scenarios, nonadherence and early discontinuation accounted for ∼24% of resources being wasted within the first year of CGM initiation. Similar results were observed using the local costs in the other countries analyzed.

CONCLUSIONS

The healthcare resource waste associated with traditional CGM nonadherence and early discontinuation warrants deliberate consideration when selecting suitable patients for this technology.

Effect of artificial pancreas systems on glycaemic control in patients with type 1 diabetes: a systematic review and meta-analysis of outpatient randomised controlled trials

BACKGROUND

Closed-loop artificial pancreas systems have been in development for several years, including assessment in numerous varied outpatient clinical trials. We aimed to summarise the efficacy and safety of artificial pancreas systems in outpatient settings and explore the clinical and technical factors that can affect their performance.

METHODS

We did a systematic review and meta-analysis of randomised controlled trials comparing artificial pancreas systems (insulin only or insulin plus glucagon) with conventional pump therapy (continuous subcutaneous insulin infusion [CSII] with blinded continuous glucose monitoring [CGM] or unblinded sensor-augmented pump [SAP] therapy) in adults and children with type 1 diabetes. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials for studies published from 1946, to Jan 1, 2017. We excluded studies not published in English, those involving pregnant women or participants who were in hospital, and those testing adjunct medications other than glucagon. The primary outcome was the mean difference in percentage of time blood glucose concentration remained in target range (3·9-10 mmol/L or 3·9-8 mmol/L, depending on the study), assessed by random-effects meta-analysis. This study is registered with PROSPERO, number 2015:CRD42015026854.

FINDINGS

We identified 984 reports; after exclusions, 27 comparisons from 24 studies (23 crossover and one parallel design) including a total of 585 participants (219 in adult studies, 265 in paediatric studies, and 101 in combined studies) were eligible for analysis. Five comparisons assessed dual-hormone (insulin and glucagon), two comparisons assessed both dual-hormone and single-hormone (insulin only), and 20 comparisons assessed single-hormone artificial pancreas systems. Time in target was 12·59% higher with artificial pancreas systems (95% CI 9·02-16·16; p<0·0001), from a weighted mean of 58·21% for conventional pump therapy (I²=84%). Dual-hormone artificial pancreas systems were associated with a greater improvement in time in target range compared with single-hormone systems (19·52% [95% CI 15·12-23·91] vs 11·06% [6·94 to 15·18]; p=0·006), although six of seven comparisons compared dual-hormone systems to CSII with blinded CGM, whereas 21 of 22 single-hormone comparisons had SAP as the comparator. Single-hormone studies had higher heterogeneity than dual-hormone studies (I² 79% vs 66%). Bias assessment characteristics were incompletely reported in 12 of 24 studies, no studies masked participants to the intervention assignment, and masking of outcome assessment was not done in 12 studies and was unclear in 12 studies.

INTERPRETATION

Artificial pancreas systems uniformly improved glucose control in outpatient settings, despite heterogeneous clinical and technical factors.

FUNDING

None.

Design and Methods of a Randomized Trial of Continuous Glucose Monitoring in Persons With Type 1 Diabetes With Impaired Glycemic Control Treated With Multiple Daily Insulin Injections (GOLD Study)

BACKGROUND

The majority of individuals with type 1 diabetes today have glucose levels exceeding guidelines. The primary aim of this study was to evaluate whether continuous glucose monitoring (CGM), using the Dexcom G4 stand-alone system, improves glycemic control in adults with type 1 diabetes treated with multiple daily insulin injections (MDI).

METHODS

Individuals with type 1 diabetes and inadequate glycemic control (HbA1c ≥ 7.5% = 58 mmol/mol) treated with MDI were randomized in a cross-over design to the Dexcom G4 versus conventional care for 6 months followed by a 4-month wash-out period. Masked CGM was performed before randomization, during conventional treatment, and during the wash-out period to evaluate effects on hypoglycemia, hyperglycemia, and glycemic variability. Questionnaires were used to evaluate diabetes treatment satisfaction, fear of hypoglycemia, hypoglycemia confidence, diabetes-related distress, overall well-being, and physical activity during the different phases of the trial. The primary endpoint was the difference in HbA1c at the end of each treatment phase.

RESULTS

A total of 205 patients were screened, of whom 161 were randomized between February and December 2014. Study completion is anticipated in April 2016.

CONCLUSIONS

It is expected that the results of this study will establish whether using the Dexcom G4 stand-alone system in individuals with type 1 diabetes treated with MDI improves glycemic control, reduces hypoglycemia, and influences quality-of-life indicators and glycemic variability.

Using technology to advance type 1 diabetes care among women during the reproductive years and in pregnancy

The prevalence of diabetes is increasing globally. Technology to improve care among individuals with diabetes is constantly being developed. Women living with Type 1 Diabetes Mellitus (T1DM) have unique challenges affecting their glucose control relating to menstrual cycles, pregnancy, and menopause. The purpose of this review is to examine the literature related to the use of technology to help women with T1DM manage their diabetes during the reproductive years, pregnancy, and beyond. Continuous subcutaneous insulin infusion (CSII) therapy can provider equivalent or better glucose control when compared with multiple daily injections (MDI), with less hypoglycemia, diabetic ketoacidosis, and weight gain. The CSII therapy has features that could help improve glucose control over the menstrual cycle, menopause, and pregnancy, although the most studied of these stages is pregnancy. Continuous glucose monitoring (CGM) can be combined with any insulin delivery system (MDI or CSII) to provide data on glucose values every few minutes and show glucose trends over time. CGM introduction can highlight glucose variability for women with T1DM, may be beneficial during pregnancy, and can reduce hypoglycemia. Sensor-augmented pump therapy and hybrid artificial pancreas (closed-loop) systems are promising tools that improve outcomes among individuals with diabetes. The use of modern technology to improve glucose and metabolic control among menopausal women with diabetes has not been well studied. Internet and phone-based technologies are emerging as important tools that may help with diabetes self-care for women living with diabetes.

Predicting the effectiveness of insulin pump therapy on glycemic control in clinical practice: a retrospective study of patients with type 1 diabetes from 10 outpatient diabetes clinics in Sweden over 5 years

BACKGROUND

Multicenter long-term studies of predictors for the effectiveness of continuous subcutaneous insulin infusion (CSII) in clinical practice are lacking. We hypothesized that there are substantially greater reductions in hemoglobin A1c (HbA1c) in patients with poor glycemic control and that other predictors may also exist.

SUBJECTS AND METHODS

We used data from 10 outpatient diabetic clinics in Sweden and studied CSII treatment over 5 years. Patients with HbA1c values available ≤ 6 months before starting CSII and at 5 years were included (n = 272, 82% of CSII patients) along with 2,437 contemporaneous controls on multiple daily insulin injections (MDI). Baseline variables evaluated were age, sex, diabetes duration, insulin dose, body mass index (BMI), HbA1c at baseline, and outpatient clinical care unit.

RESULTS

At 5 years, significantly greater reductions in HbA1c by CSII compared with MDI were found for patients with higher baseline HbA1c (P = 0.032) and lower baseline BMI (P = 0.013). For baseline HbA1c levels of 7.0%, 8.0%, and 9.0% and a BMI of 25 kg/m(2), the reduction in HbA1c level by CSII was 0.08% (difference not significant), 0.16% (95% confidence interval, 0.03-0.29%), and 0.25% (95% confidence interval, 0.11-0.39%), respectively. Corresponding analyses for the change in HbA1c level from start to 1 and 2 years revealed a significant interaction of insulin pump therapy only with baseline HbA1c levels (P < 0.001 and P = 0.030, respectively). The interaction term between outpatient clinical care unit and CSII treatment was statistically significant for some care units, with some care units demonstrating a benefit from CSII and others demonstrating a detriment.

CONCLUSIONS

Patients with high HbA1c levels have a greater probability of improved HbA1c after initiating pump therapy, but effects remain relatively modest even for patients with poor control. Factors predicting successful insulin pump use need further study.

Continuous glucose monitoring pilot in low-income type 1 diabetes patients

BACKGROUND

Continuous glucose monitoring (CGM) has been shown to be a valuable tool to improve glycemic control in patients with diabetes. The objective of this pilot study was to develop and implement CGM in an existing diabetes clinic for low-income patients on multiple daily injections.

SUBJECTS AND METHODS

This was a single-center, prospective, randomized controlled, crossover pilot study. Initial focus groups were held to create low-literacy, Spanish and English guides to the use of carbohydrate counting and CGM. These tools were implemented to train participants on carbohydrate counting and insulin adjustments participants. Subjects were then randomized to start in Group A (CGM) or Group B (self-monitoring blood glucose and then switched after 28 weeks). Hemoglobin A1c (HbA1c) was obtained at baseline and at the end of both study phases.

RESULTS

Twenty-five economically challenged, primarily Latino participants with minimal prior education on intensive diabetes management completed the study. No significant reduction in HbA1c or decrease in time spent in parameters of low and high blood glucose was shown. However, eighty percent of participants who completed the study wanted to continue to use CGM once the research study was over. The participants also felt that the CGM made adjusting insulin easier.

CONCLUSIONS

CGM can be implemented in patients from a low-income public clinic; however, HbA1c reduction was not achieved. Given the underlying lack of baseline self-management knowledge, a longer trial might be necessary to see benefit with CGM in this population.

Role of continuous glucose monitoring in the management of diabetic pregnancy

Self-monitoring of blood glucose (SMBG) with intermittent capillary glucose fingerstick tests is currently the universally accepted method of glucose monitoring in pregnancy. During pregnancy SMBG tests are recommended before and after meals and before bed (typically 7 values/d). Continuous glucose monitoring systems consist of a disposable subcutaneous glucose-sensing device, electrochemically measuring glucose levels in subcutaneous tissues every 10 seconds, providing an average interstitial glucose value every 5 minutes (typically 288 values/d). From a research perspective this provides unprecedented insights into the pathophysiology of glucose metabolism, while from a clinical perspective it can facilitate enhanced patient-professional decision making, patient motivation, and improved glycaemic control. CGM has thus been described as a "roadmap for effective self-management" and as a "stepping stone in the journey towards a cure." This review will consider the lessons learned and evidence supporting current and potential future use of CGM in the management of diabetes in pregnancy.

Pilot study of a prototype minimally invasive intradermal continuous glucose monitor

INTRODUCTION

The purpose of this study was to assess point accuracy, rate-of-change accuracy, and safety of a prototype, minimally invasive continuous glucose monitoring (CGM) device over a 12 h in-clinic study. The CGM system consisted of a wireless electronics module with a disposable glucose sensor attached to the bottom. The electronics module was affixed to the abdomen using an adhesive pad on the bottom of the disposable sensor housing.

METHODS

Two CGM sensors were inserted into the abdominal tissue (left and right) of 15 adults aged 26-67 years, 5 with normoglycemia, 5 with type 1 diabetes, and 5 with type 2 diabetes. Over a 12 h period, each participant was fed three meals. Reference venous blood samples were drawn at periodic intervals (12.4 ± 5.3 min), and glucose was measured at the bedside using a laboratory reference method. For each participant, a single plasma equivalent glucose concentration was used for retrospective sensor calibration.

RESULTS

A total of 1082 paired data points were obtained from 15 subjects and 25 of 30 sensors. Statistical analysis yielded a mean absolute relative difference of 12.6% and a mean absolute difference of 16.0 mg/dl. Continuous glucose error grid analysis showed the combined point and rate-of-change accuracy was 97.4% in zone A and 1.5% in zone B (98.9% A+B), with 1.1% erroneous readings.

CONCLUSIONS

The prototype CGM system provided clinically accurate results 98.9% of the time and was well tolerated by participants, with little or no pain and no adverse events.