Continuous glucose monitoring: A review of the technology and clinical use

Prediction Quality of Glucose Trend Indicators in Two Continuous Tissue Glucose Monitoring Systems

BACKGROUND

Continuous interstitial glucose monitoring (CGM) systems often provide glucose trend indicators (e.g., arrows) in addition to current glucose values. These indicators are recommended to be used in therapeutic decisions, because they are ascribed predictive qualities by CGM system manufacturers and expert committees. This study assessed how reliably trend indicators match future glucose change, because such information is missing.

METHODS

In a clinical trial, two different CGM systems were used by 20 participants, with two sensors of each system per patient. Participants used the systems for 14 days with three study site visits (48 h each). During study site visits, glucose trend indicators, as displayed by the CGM systems, were recorded at least once per hour during daytime and once at night in a diary. In addition, CGM data were downloaded from the devices. Trend indicators were compared with glucose change calculated from CGM data >30 min after recording the trend indicator.

RESULTS

Approximately 60% of trend indicators matched the glucose change calculated from CGM data. More than 10% of trend indicators differed by at least two trend indicator categories. Focusing on trend indicators recorded around carbohydrate (CHO) intake and insulin deliveries resulted in approximately half of trend indicators matching the calculated glucose change.

CONCLUSIONS

Trend indicators do not always match future glucose change, especially within the first few hours after CHO intake and insulin deliveries. Manufacturers' labeling and recommendations should reflect this, so that CGM users can make informed decisions.

Current and Emerging Trends in Point-of-Care Technology and Strategies for Clinical Validation and Implementation

BACKGROUND

Point-of-care technology (POCT) provides actionable information at the site of care to allow rapid clinical decision-making. With healthcare emphasis shifting toward precision medicine, population health, and chronic disease management, the potential impact of POCT continues to grow, and several prominent POCT trends have emerged or strengthened in the last decade.

CONTENT

This review summarizes current and emerging trends in POCT, including technologies approved or cleared by the Food and Drug Administration or in development. Technologies included have either impacted existing clinical diagnostics applications (e.g., continuous monitoring and targeted nucleic acid testing) or are likely to impact diagnostics delivery in the near future. The focus is limited to in vitro diagnostics applications, although in some sections, technologies beyond in vitro diagnostics are also included given the commonalities (e.g., ultrasound plug-ins for smart phones). For technologies in development (e.g., wearables, noninvasive testing, mass spectrometry and nuclear magnetic resonance, paper-based diagnostics, nanopore-based devices, and digital microfluidics), we also discuss their potential clinical applications and provide perspectives on strategies beyond technological and analytical proof of concept, with the end goal of clinical implementation and impact.

SUMMARY

The field of POCT has witnessed strong growth over the past decade, as evidenced by new clinical or consumer products or research and development directions. Combined with the appropriate strategies for clinical needs assessment, validation, and implementation, these and future POCTs may significantly impact care delivery and associated outcomes and costs.

Hypoglycaemia in type 1 diabetes: technological treatments, their limitations and the place of psychology

Advances in technology allowing improved insulin delivery and glucose monitoring can significantly reduce the burden of hypoglycaemia when used appropriately. However, limitations of the current technology, and the skills, commitment and motivation required to use them, mean that it does not work for all people. Education and informed professional support are key to success. In the context of problematic hypoglycaemia, data suggest that newer technology has lower efficacy and uptake in those with most need. Identifying the causes of hypoglycaemia and understanding some of the underlying behavioural drivers may prove useful and psycho-educational strategies may be effective in selected individuals. Ultimately, as in many spheres of medicine, successful management of problematic hypoglycaemia depends upon matching the right treatment to the right individual.

Interstitial Glucose and Physical Exercise in Type 1 Diabetes: Integrative Physiology, Technology, and the Gap In-Between

Continuous and flash glucose monitoring systems measure interstitial fluid glucose concentrations within a body compartment that is dramatically altered by posture and is responsive to the physiological and metabolic changes that enable exercise performance in individuals with type 1 diabetes. Body fluid redistribution within the interstitial compartment, alterations in interstitial fluid volume, changes in rate and direction of fluid flow between the vasculature, interstitium and lymphatics, as well as alterations in the rate of glucose production and uptake by exercising tissues, make for caution when interpreting device read-outs in a rapidly changing internal environment during acute exercise. We present an understanding of the physiological and metabolic changes taking place with acute exercise and detail the blood and interstitial glucose responses with different forms of exercise, namely sustained endurance, high-intensity, and strength exercises in individuals with type 1 diabetes. Further, we detail novel technical information on currently available patient devices. As more health services and insurance companies advocate their use, understanding continuous and flash glucose monitoring for its strengths and limitations may offer more confidence for patients aiming to manage glycemia around exercise.

Diabetes Device Use and Glycemic Control among Youth with Type 1 Diabetes: A Single-Center, Cross-Sectional Study

AIM

The purpose of this cross-sectional study was to determine the rates of diabetes device use (insulin pump and continuous glucose monitor (CGM)) and association with glycemic control in youth with type 1 diabetes in a large, diverse pediatric center.

METHODS

Demographic and clinical data were obtained from 1992 patients who met the eligibility criteria (age < 26 years, diabetes duration ≥ 1 year, and ≥1 clinic visit in the preceding 12 months). Statistical analyses assessed the likelihood of device use based on demographic characteristics and the association between device use and glycemic control based on most recent hemoglobin A1c (HbA1c).

RESULTS

Mean age was 13.8 ± 4.2 years, 50.7% were female, diabetes duration was 6.2 ± 4 years, and mean HbA1c was 8.7 ± 1.8%. Overall, 38.2% of patients were on pump therapy and 18.5% were on CGM. Patients who were non-Hispanic (NH) white, privately insured, and with primary English-speaking parent(s) had higher rates of insulin pump use, as well as CGM use (P < 0.001 for both). Female patients had higher rates of pump use only (P < 0.01). Private health insurance, NH white race/ethnicity, and CGM use were each associated with lower HbA1c (P = 0.03, <0.001, and <0.008, resp.).

CONCLUSION

At a large, diverse, pediatric diabetes center, disparities in diabetes device use were present across sex, race/ethnicity, health insurance coverage, and primary language of parent(s). CGM use was associated with lower HbA1c. Quality improvement efforts are underway to ensure improved access, education, and clinical programs for advanced diabetes devices for T1D patients.