Current Continuous Glucose Monitoring Systems Research Articles

Exploring the Continuous Glucose Monitoring in Pediatric Diabetes: Current Practices, Innovative Metrics, and Future Implications

Continuous glucose monitoring (CGM) systems, including real-time CGM and intermittently scanned CGM, have revolutionized diabetes management, particularly in children and adolescents with type 1 diabetes (T1D). These systems provide detailed insights into glucose variability and detect asymptomatic and nocturnal hypoglycemia, addressing limitations of traditional self-monitoring blood glucose methods. CGM devices measure interstitial glucose concentrations constantly, enabling proactive therapeutic decisions and optimization of glycemic control through stored data analysis. CGM metrics such as time in range, time below range, and coefficient of variation are crucial for managing T1D, with emerging metrics like time in tight range and glycemia risk index showing potential for enhanced glycemic assessment. Recent advancements suggest the utility of CGM systems in monitoring the early stages of T1D and individuals with obesity complicated by pre-diabetes, highlighting its therapeutic versatility. This review discusses the current CGM systems for T1D during the pediatric age, established and emerging metrics, and future applications, emphasizing the critical role of CGM devices in improving glycemic control and clinical outcomes in children and adolescents with diabetes.

Perceptions of Continuous Glucose Monitoring Systems in the T1D Exchange Diabetes Registry: Satisfaction, Concerns, and Areas for Future Improvement.

Manufacturers continue to improve performance and usability of continuous glucose monitoring (CGM) systems. As CGM becomes a standard of care, especially for people on insulin therapy, it is important to routinely gauge how satisfied people with diabetes are with this technology. This article describes survey feedback from a large cohort of people with diabetes using older and current CGM systems and highlights areas of current satisfaction, concern, and future system improvement.

Practical Application of Continuous Glucose Monitoring in Clinical Practice: Case Studies.

The prevalence of diabetes continues to rise exponentially and contributes significantly to morbidity, mortality, and health care resource utilization. Individuals with diabetes have adopted continuous glucose monitoring (CGM) as their preferred method for glucose measurement. Primary care clinicians should become proficient in utilizing this technology in their practices. This case-based article provides practical guidance in CGM interpretation allowing patients to become successful partners in diabetes self-management. Our approach to data interpretation and shared decision-making is applicable to all current CGM systems.

Comparing the Rise in Glucose Concentration in Blood, Aqueous and Interstitial Fluid During a Glucose Tolerance Test.

The purpose of the study was to determine if aqueous glucose levels rise in a comparable time frame to interstitial fluid and could therefore be suitable for a continuous glucose monitoring (CGM) site. An intravenous glucose tolerance test was performed on five New Zealand white rabbits. Aqueous humor from the posterior and anterior chamber of the eye and venous blood were sampled for glucose concentration measurement. Glucose concentrations in the interstitial fluids were monitored using a CGM system. A compartment model was created to map the glucose response curves in each compartment. The delay in rising glucose concentrations between blood and interstitial fluid and aqueous humor in the posterior chamber and anterior chamber of the eye were analyzed. The results showed a statistically similar time lag and rate of change in glucose concentrations between blood and interstitial fluids or aqueous humor in either the posterior or anterior chamber. The results of this study add further support to the aqueous humor being used as an alternative CGM site. The study provides the basis for developing an intraocular continuous glucose sensor that can overcome limitations of current CGM systems.

Hypoglycemia detection with current continuous glucose monitoring systems: How accurate are they?

Hypoglycemia detection with current continuous glucose monitoring systems: How accurate are they?

893-P: Miniaturized, User-Insertable Wireless Continuous Glucose Monitoring System with Next Generation Speed, Accuracy, and Longevity

The accuracy, response speed, cost, and size are important determinants of the performance of a Continuous Glucose Monitoring (CGM) system. Current CGM systems either require (i) percutaneous wires with bulky skin-worn transmitters, frequent removal/insertion, and thousands of dollars, or (ii) bulky implants, special semi-surgical procedures, and frequent recalibrations. By integrating modern semiconductor and nano technologies, IMS invented miniaturized (0.1mmx0.6mmx3mm i.e., smaller than a sesame seed) fully wireless, minimally invasive subdermal CGM platform. The sensor is user-insertable under the skin using an injector and is also user-removable. It is powered via an external smartwatch transmitter using standard RFID technology. This enables low power RF communication with the transmitter. The transmitter uses a bluetooth low-energy link to send the data to a smartphone reader enabling machine-learning based decision support. IMS has verified the system through extensive in-vitro and in-vivo testing; the latest test for more than 1 month in a porcine model (Figure 1). The sensor shows fast response speed, best-in-class accuracy, and highly biocompatible operation due to use of standard materials and small size. We are currently working to get FDA IDE for first-in-human study. Figure 1. Sensor Performance Results (a) using FDA iCGM (b) Clarke Error Grid. Disclosure M. Mujeeb-U-Rahman: None. M. Honarvar Nazari: None. M. Sencan: Employee; Self; Integrated Medical Sensors. Funding National Institutes of Health (DK109811, DK111001)

Hypoglycaemia Remains the Key Obstacle to Optimal Glycaemic Control - Continuous Glucose Monitoring is the Solution.

We queried PubMed and other internet databases to identify studies, meta-analyses, review articles and other data sources regarding hypoglycaemia incidence/costs/impacts and continuous glucose monitoring (CGM) use. Our analysis of the evidence showed that hypoglycaemia remains a significant health concern and a primary obstacle to optimal adherence to prescribed diabetes treatment. In addition to its adverse clinical consequences, hypoglycaemia negatively impacts quality of life and places additional financial burdens on patients, patient families, employers and healthcare payers. Clinical trials have shown that the use of CGM can reduce the incidence and duration of hypoglycaemic episodes. This article reviews relevant CGM studies, discusses the prevalence and clinical/financial implications of hypoglycaemia, and explores the strengths and limitations of current CGM systems in minimising the burden of hypoglycaemia.

Role of Continuous Glucose Monitoring in Clinical Trials: Recommendations on Reporting.

Thanks to significant improvements in the precision, accuracy, and usability of continuous glucose monitoring (CGM), its relevance in both ambulatory diabetes care and clinical research is increasing. In this study, we address the latter perspective and derive provisional reporting recommendations. CGM systems have been available since around the year 2000 and used primarily in people with type 1 diabetes. In contrast to self-measured glucose, CGM can provide continuous real-time measurement of glucose levels, alerts for hypoglycemia and hyperglycemia, and a detailed assessment of glycemic variability. Through a broad spectrum of derived glucose data, CGM should be a useful tool for clinical evaluation of new glucose-lowering medications and strategies. It is the only technology that can measure hyperglycemic and hypoglycemic exposure in ambulatory care, or provide data for comprehensive assessment of glucose variability. Other advantages of current CGM systems include the opportunity for improved self-management of glycemic control, with particular relevance to those at higher risk of or from hypoglycemia. We therefore summarize the current status and limitations of CGM from the perspective of clinical trials and derive suggested recommendations for how these should facilitate optimal CGM use and reporting of data in clinical research.

What Are the Next Steps in Continuous Glucose Monitoring?

The development of glucose sensors for continuous glucose monitoring (CGM) is likely still in its early days. A number of novel approaches-along with many attempts to improve current CGM systems-are in development. The next generation of glucose sensors (NGGS) will also enable, for example, reliable glucose measurement in the low glycemic range. NGGS systems represent an important step forward for closed-loop systems. This commentary discusses a number of aspects that are relevant in this context.

Contribution of an Intrinsic Lag of Continuous Glucose Monitoring Systems to Differences in Measured and Actual Glucose Concentrations Changing at Variable Rates in Vitro

Current continuous glucose monitoring (CGM) systems measure glucose levels in the interstitial fluid to estimate blood glucose concentration. A lag time has been observed between CGM system glucose readings and blood glucose levels when glucose levels are changing. Although this lag has been attributed to the time it takes glucose to equilibrate between blood and interstitial fluid compartments, it is unclear to what extent these inaccuracies reflect an intrinsic delay of the device itself. Four Guardian® REAL-Time CGM systems (CGMSs) (Medtronic Diabetes, Minimed, CA) and eight glucose sensors were tested in glucose solutions prepared in Krebs bicarbonate buffers at 37 °C. Glucose readings obtained from CGMSs were compared with actual glucose concentrations during controlled changes in glucose concentration performed at four rates (30, 90, and 220 mg/dl/hr(-1) and an instantaneous change of 110 mg/dl) using a linear gradient maker. Irrespective of the rate and direction of changes in glucose concentration, the readings obtained from CGMSs were significantly different from actual glucose levels. The faster the rise or fall in actual glucose concentration, the more pronounced the mismatch with CGMS glucose readings. Furthermore, the intrinsic lag times (8.3 to 40.1 min) were high enough to account for the lags reported in previous in vivo studies. The lag intrinsic of the CGMS may make a significant contribution to the mismatch between CGM system readings and blood glucose concentrations.

Microdialysis based device for continuous extravascular monitoring of blood glucose

Glycemic control of intensive care patients can be beneficial for this patient group but the continuous determination of their glucose concentration is challenging. Current continuous glucose monitoring systems based on the measurement of interstitial fluid glucose concentration struggle with sensitivity losses, resulting from biofouling or inflammation reactions. Their use as decision support systems for the therapeutic treatment is moreover hampered by physiological time delays as well as gradients in glucose concentration between plasma and interstitial fluid. To overcome these drawbacks, we developed and clinically evaluated a system based on microdialysis of whole blood. Venous blood is heparinised at the tip of a double lumen catheter and pumped through a membrane based micro-fluidic device where protein-free microdialysate samples are extracted. Glucose recovery as an indicator of long term stability was studied in vitro with heparinised bovine blood and remained highly stable for 72 h. Clinical performance was tested in a clinical trial in eight healthy volunteers undergoing an oral glucose tolerance test. Glucose concentrations of the new system and the reference method correlated at a level of 0.96 and their mean relative difference was 1.9 +/- 11.2%. Clinical evaluation using Clark's Error Grid analysis revealed that the obtained glucose concentrations were accurate and clinically acceptable in 99.6% of all cases. In conclusion, results of the technical and clinical evaluation suggest that the presented device delivers microdialysate samples suitable for accurate and long term stable continuous glucose monitoring in blood.

Minimally-Invasive and Non-Invasive Continuous Glucose Monitoring Systems: Indications, Advantages, Limitations and Clinical Aspects

Accurate and reliable devices sensing glucose on a (near)-continuous basis may facilitate specific therapeutic adjustments that need to be made to avoid hypo- and hyperglycaemic excursions, thereby improving metabolic control. Current continuous glucose monitoring (CGM) systems indicate the glucose level, the direction and magnitude of change of glucose levels, and can be used to assess glycaemic variability. In addition, real-time CGM sensors can serve as a tool to predict impending glucose excursions, thereby providing alarm signals of hypo- and hyperglycaemic values warning the patient to take preventative actions. Quality of life may also improve by using CGM via reducing the fear of hypoglycaemia. Particularly patients with brittle diabetes, hypoglycaemia unawareness, gastroparesis, pregnant women, or pump users, who are motivated to participate in their diabetes care and are technologically adept, may benefit from CGM. However, to successfully implement CGM in daily practice, these devices must be accurate and reliable, and one must be aware of the limitations of current CGM systems, that originate from physiological and technical aspects. Whether CGM succeeds in improving metabolic control, reducing hypoglycaemic episodes, and improving quality of life in the majority of patients remains to be proven. Should this be the case, real-time CGM may reduce chronic diabetic complications, and avoid hospitalisations, thereby reducing health care costs. In this article we will review indications, advantages, limitations, clinical and technical aspects of current minimally-invasive and non-invasive CGM sensors.