While A1C is well established as an important risk marker for diabetes complications, with the increasing use of continuous glucose monitoring (CGM) to help facilitate safe and effective diabetes ...management, it is important to understand how CGM metrics, such as mean glucose, and A1C correlate. Estimated A1C (eA1C) is a measure converting the mean glucose from CGM or self-monitored blood glucose readings, using a formula derived from glucose readings from a population of individuals, into an estimate of a simultaneously measured laboratory A1C. Many patients and clinicians find the eA1C to be a helpful educational tool, but others are often confused or even frustrated if the eA1C and laboratory-measured A1C do not agree. In the U.S., the Food and Drug Administration determined that the nomenclature of eA1C needed to change. This led the authors to work toward a multipart solution to facilitate the retention of such a metric, which includes renaming the eA1C the glucose management indicator (GMI) and generating a new formula for converting CGM-derived mean glucose to GMI based on recent clinical trials using the most accurate CGM systems available. The final aspect of ensuring a smooth transition from the old eA1C to the new GMI is providing new CGM analyses and explanations to further understand how to interpret GMI and use it most effectively in clinical practice. This Perspective will address why a new name for eA1C was needed, why GMI was selected as the new name, how GMI is calculated, and how to understand and explain GMI if one chooses to use GMI as a tool in diabetes education or management.
Previous clinical trials showing the benefit of continuous glucose monitoring (CGM) in the management of type 1 diabetes predominantly have included adults using insulin pumps, even though the ...majority of adults with type 1 diabetes administer insulin by injection.
To determine the effectiveness of CGM in adults with type 1 diabetes treated with insulin injections.
Randomized clinical trial conducted between October 2014 and May 2016 at 24 endocrinology practices in the United States that included 158 adults with type 1 diabetes who were using multiple daily insulin injections and had hemoglobin A1c (HbA1c) levels of 7.5% to 9.9%.
Random assignment 2:1 to CGM (n = 105) or usual care (control group; n = 53).
Primary outcome measure was the difference in change in central-laboratory-measured HbA1c level from baseline to 24 weeks. There were 18 secondary or exploratory end points, of which 15 are reported in this article, including duration of hypoglycemia at less than 70 mg/dL, measured with CGM for 7 days at 12 and 24 weeks.
Among the 158 randomized participants (mean age, 48 years SD, 13; 44% women; mean baseline HbA1c level, 8.6% SD, 0.6%; and median diabetes duration, 19 years interquartile range, 10-31 years), 155 (98%) completed the study. In the CGM group, 93% used CGM 6 d/wk or more in month 6. Mean HbA1c reduction from baseline was 1.1% at 12 weeks and 1.0% at 24 weeks in the CGM group and 0.5% and 0.4%, respectively, in the control group (repeated-measures model P < .001). At 24 weeks, the adjusted treatment-group difference in mean change in HbA1c level from baseline was -0.6% (95% CI, -0.8% to -0.3%; P < .001). Median duration of hypoglycemia at less than <70 mg/dL was 43 min/d (IQR, 27-69) in the CGM group vs 80 min/d (IQR, 36-111) in the control group (P = .002). Severe hypoglycemia events occurred in 2 participants in each group.
Among adults with type 1 diabetes who used multiple daily insulin injections, the use of CGM compared with usual care resulted in a greater decrease in HbA1c level during 24 weeks. Further research is needed to assess longer-term effectiveness, as well as clinical outcomes and adverse effects.
clinicaltrials.gov Identifier: NCT02282397.
Context and Aim
Continuous glucose monitoring (CGM) is becoming widely accepted as an adjunct to diabetes management. Compared to standard care, CGM can provide detailed information about glycaemic ...variability in an internationally standardised ambulatory glucose profile, enabling more informed user and clinician decision making. We aimed to review the evidence, user experience and cost‐effectiveness of CGM.
Methods
A literature search was conducted by combining subject headings ‘CGM’ and ‘flash glucose monitoring’, with key words ‘type 1 diabetes’ and ‘type 2 diabetes’, limited to ‘1999 to current’. Further evidence was obtained from relevant references of retrieved articles.
Results
There is a strong evidence for CGM use in people with type 1 diabetes, with benefits of reduced glycated haemoglobin and hypoglycaemia, and increased time in range. While the evidence for CGM use in type 2 diabetes is less robust, similar benefits have been demonstrated. CGM can improve diabetes‐related satisfaction in people with diabetes (PWD) and parents of children with diabetes, as well as the clinician experience. However, CGM does have limitations including cost, accuracy and perceived inconvenience. Cost‐effectiveness analyses have indicated that CGM is a cost‐effective adjunct to type 1 diabetes management that is associated with reduced diabetes‐related complications and hospitalisation.
Conclusions
Continuous glucose monitoring is revolutionising diabetes management. It is a cost‐effective adjunct to diabetes management that has the potential to improve glycaemic outcomes and quality of life in PWD, especially type 1 diabetes.
To determine accuracy, safety and acceptability of the FreeStyle Libre Flash Glucose Monitoring System in the paediatric population.
Eighty-nine study participants, aged 4-17 years, with type 1 ...diabetes were enrolled across 9 diabetes centres in the UK. A factory calibrated sensor was inserted on the back of the upper arm and used for up to 14 days. Sensor glucose measurements were compared with capillary blood glucose (BG) measurements. Sensor results were masked to participants.
Clinical accuracy of sensor results versus BG results was demonstrated, with 83.8% of results in zone A and 99.4% of results in zones A and B of the consensus error grid. Overall mean absolute relative difference (MARD) was 13.9%. Sensor accuracy was unaffected by patient factors such as age, body weight, sex, method of insulin administration or time of use (day vs night). Participants were in the target glucose range (3.9-10.0 mmol/L) ∼50% of the time (mean 12.1 hours/day), with an average of 2.2 hours/day and 9.5 hours/day in hypoglycaemia and hyperglycaemia, respectively. Sensor application, wear/use of the device and comparison to self-monitoring of blood glucose were rated favourably by most participants/caregivers (84.3-100%). Five device related adverse events were reported across a range of participant ages.
Accuracy, safety and user acceptability of the FreeStyle Libre System were demonstrated for the paediatric population. Accuracy of the system was unaffected by subject characteristics, making it suitable for a broad range of children and young people with diabetes.
NCT02388815.
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► We review the advances in non-invasive glucose monitoring in last two decades. ► Initially, the various non-invasive glucose monitoring techniques are described. ► Thereafter, the ...non-invasive glucose monitoring devices are presented. ► The future trends in technology are discussed in the last section.
The frequent monitoring of glucose is an essential part of diabetes management. Despite the fact that almost all the commercially successful blood glucose monitoring devices are invasive, there is an immense need to develop non-invasive glucose monitoring (NGM) devices that will alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking the blood sample for glucose testing. There have been numerous developments in the field of NGM during the last decade, which stress the need for a critical review. This manuscript aims to review the various NGM techniques and devices. The challenges and future trends in NGM are also discussed.
The use of continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems has gained wide acceptance in diabetes care. These devices have been demonstrated to be ...clinically valuable, improving glycemic control and reducing risks of hypoglycemia in ambulatory patients with type 1 diabetes and type 2 diabetes. Approximately 30-40% of patients with type 1 diabetes and an increasing number of insulin-requiring patients with type 2 diabetes are using pump and sensor technology. As the popularity of these devices increases, it becomes very likely that hospital health care providers will face the need to manage the inpatient care of patients under insulin pump therapy and CGM. The American Diabetes Association advocates allowing patients who are physically and mentally able to continue to use their pumps when hospitalized. Health care institutions must have clear policies and procedures to allow the patient to continue to receive CSII treatment to maximize safety and to comply with existing regulations related to self-management of medication. Randomized controlled trials are needed to determine whether CSII therapy and CGM systems in the hospital are associated with improved clinical outcomes compared with intermittent monitoring and conventional insulin treatment or with a favorable cost-benefit ratio.
Providing culturally competent care to the growing number of limited-English proficiency (LEP) Latinos with diabetes in the United States is challenging.
To evaluate changes in risk factor control ...among LEP Latinos with diabetes who switched from language-discordant (English-only) primary care physicians (PCPs) to language-concordant (Spanish-speaking) PCPs or vice versa.
This pre-post, difference-in-differences study selected 1605 adult patients with diabetes who self-identified as Latino, whose preferred language was Spanish, and who switched PCPs between January 1, 2007, and December 31, 2013. Study participants were members of the Kaiser Permanente Northern California health care system (an integrated health care delivery system with access to bilingual PCPs and/or professional interpreter services). Spanish-speaking and English-only PCPs were identified by self-report or utilization data.
Change in patient-PCP language concordance after switching PCPs.
Glycemic control (glycated hemoglobin HbA1c < 8%), poor glycemic control (HbA1c > 9%), low-density-lipoprotein (LDL) control (LDL < 100 mg/dL), and systolic blood pressure (SBP) control (SBP < 140 mm Hg).
Overall, 1605 LEP Latino adults with diabetes (mean SD age, 60.5 13.1 years) were included in this study, and there was a significant net improvement in glycemic and LDL control among patients who switched from language-discordant PCPs to concordant PCPs relative to those who switched from one discordant PCP to another discordant PCP. After adjustment and accounting for secular trends, the prevalence of glycemic control increased by 10% (95% CI, 2% to 17%; P = .01), poor glycemic control decreased by 4% (95% CI, -10% to 2%; P = .16) and LDL control increased by 9% (95% CI, 1% to 17%; P = .03). No significant changes were observed in SBP control. Prevalence of LDL control increased 15% (95% CI, 7% to 24%; P < .001) among LEP Latinos who switched from concordant to discordant PCPs. Risk factor control did not worsen following a PCP switch in any group.
We observed significant improvements in glycemic control among LEP Latino patients with diabetes who switched from language-discordant to concordant PCPs. Facilitating language-concordant care may be a strategy for diabetes management among LEP Latinos.
As the increasing prevalence of type 2 diabetes mellitus has put pressure on health systems to appropriately manage these patients, there have been a growing number of mobile apps designed to improve ...the self-management of diabetes. One such app, BlueStar, has been shown to significantly reduce hemoglobin A
(HbA
) levels in small studies and is the first app in the United States to receive Food and Drug Administration approval as a mobile prescription therapy. However, the impact of the app across real-world population among different clinical sites and health systems remains unclear.
The primary objective of this study was to conduct a pragmatic randomized controlled trial of the BlueStar mobile app to determine if app usage leads to improved HbA
levels among diverse participants in real-life clinical contexts. We hypothesized that this mobile app would improve self-management and HbA
levels compared with controls.
The study consisted of a multicenter pragmatic randomized controlled trial. Overall, 110 participants randomized to the immediate treatment group (ITG) received the intervention for 6 months, and 113 participants randomized to the wait-list control (WLC) group received usual care for the first 3 months and then received the intervention for 3 months. The primary outcome was glucose control measured by HbA
levels at 3 months. Secondary outcomes assessed intervention impact on patient self-management, experience of care, and self-reported health utilization using validated scales, including the Problem Areas in Diabetes, the Summary of Diabetes Self-Care Activities, and the EuroQol-5D. Intervention usage data were collected directly from the app.
The results of an analysis of covariance controlling for baseline HbA
levels did not show evidence of intervention impact on HbA
levels at 3 months (mean difference ITG-WLC -0.42, 95% CI -1.05 to 0.21; P=.19). Similarly, there was no intervention effect on secondary outcomes measuring diabetes self-efficacy, quality of life, and health care utilization behaviors. An exploratory analysis of 57 ITG participants investigating the impact of app usage on HbA
levels showed that each additional day of app use corresponded with a 0.016-point decrease in participants' 3-month HbA
levels (95% CI -0.03 to -0.003). App usage varied significantly by site, as participants from 1 site logged in to the app a median of 36 days over 14 weeks (interquartile range IQR 10.5-124); those at another site used the app significantly less (median 9; IQR 6-51).
The results showed no difference between intervention and control arms for the primary clinical outcome of glycemic control measured by HbA
levels. Although there was low usage of the app among participants, results indicate contextual factors, particularly site, had a significant impact on overall usage. Future research into the patient and site-specific factors that increase app utilization are needed.
Clinicaltrials.gov NCT02813343; https://clinicaltrials.gov/ct2/show/NCT02813343 (Archived by WebCite at https://clinicaltrials.gov/ct2/show/NCT02813343).
The FreeStyle Libre flash glucose monitor became available on prescription (subject to local health authority approval) in all four nations of the UK from November 2017, a watershed moment in the ...history of diabetes care. Calibration free, the FreeStyle Libre is a disc worn on the arm for 14 days which is designed largely to replace the recommended 4–10 painful finger‐stick blood glucose tests required each day for the self‐management of diabetes. This review discusses clinical data from randomized and observational studies, considers device accuracy metrics and deliberates its popularity and the potential challenges that this new device brings to diabetes care in the UK. In randomized trials, FreeStyle Libre use is associated with a reduction in hypoglycaemia and, in observational studies, improvements in HbA1c levels. User satisfaction is high and adverse events are low. Accuracy of the FreeStyle Libre is comparable to currently available real‐time continuous glucose monitors in adults, children and during pregnancy; the cost of the FreeStyle Libre is lower. Glucose data can be visualized in multiple devices and platforms, and summarized in an ambulatory glucose profile to aid pattern recognition and insulin dose adjustment. There is a need for appropriate education, of both users and healthcare professionals, to harness the full benefits. Further randomized studies to assess the long‐term impact on HbA1c, particularly in those with high baseline HbA1c and in specific age groups, such as adolescents and young adults, are warranted. The potential impact on complications, is yet to be realized.
What's new?
The FreeStyle Libre is a novel interstitial flash glucose monitor designed to replace finger‐stick glucose tests, available through the UK National Health Service, subject to local health authority approval, from November 2017.
In this narrative review, we summarize the current evidence on the efficacy of the FreeStyle Libre with regard to HbA1c, hypoglycaemia and quality of life from randomized and observational studies.
Device accuracy data are presented, both as stand‐alone data and in comparison to existing continuous glucose monitors and blood glucose meters.
We discuss advantages, disadvantages and adverse events, and summarize key practice/safety areas aimed at helping clinicians and funders to make informed decisions about the future role of the FreeStyle Libre in diabetes management.
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