Continuous Glucose Monitoring Systems in Noninsulin-Treated People with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Narrative Review: Continuous Glucose Monitoring (CGM) in Older Adults with Diabetes

INTRODUCTION

Continuous glucose monitoring (CGM) has revolutionised diabetes care, with proven effect on glycaemic control, adverse diabetic events (such as hypoglycaemia and diabetic ketoacidosis) and hospitalisations in the general population. However, the evidence for CGM in older people is less robust.

METHOD

We conducted a narrative review of trials reporting data comparing standard blood glucose monitoring (SBGM) and CGM in adults over 65 with type 1 or type 2 diabetes who were treated with insulin published between 1999 and 2024.

RESULTS

Seventeen studies were identified, including eight retrospective cohort studies and five randomised controlled trials (RCTs). Sixteen of the 17 papers were based in Europe or North America. The studies were highly heterogeneous; however, they provided clear evidence supporting the use of CGM in reducing hypoglycemia in older adults, with potential benefits for overall wellbeing and quality of life..

CONCLUSIONS

Current approaches to diabetes care in older adults may over-rely on HbA1c (haemoglobin A1c) as a measurement of control given accuracy may be reduced in older adults and propensity for hypoglycaemia. Although goals should be personalised, avoidance of hypoglycaemia is a key goal for many older people with diabetes. There is good evidence that CGM can improve time-in-range and reduce hypoglycaemia and glucose variability in older adults. CGM should be considered for older adults as a means of reducing hypoglycaemia and associated potential harm.

Addressing the Diabetes Tsunami Requires Expanded Access to Diabetes Technologies

The use of continuous glucose monitoring (CGM) and automated insulin delivery (AID) technologies can improve patient outcomes and overall quality of life while helping to reduce the long-term costs. However, current eligibility criteria imposed by many major commercial insurers limit access to these technologies among a large portion of the diabetes population. This narrative review and commentary highlights the evidence supporting the use of CGM and AID in the various diabetes populations, discuss the current eligibility criteria that make these technologies inaccessible to individuals who would benefit, and present recommendations for modifying these criteria.

A Randomized Controlled Trial Using Continuous Glucose Monitoring to Guide Food Choices and Diabetes Self-Care in People with Type 2 Diabetes not Taking Insulin

Objective: Continuous glucose monitoring (CGM) is an effective tool for individuals with type 2 diabetes (T2D) on insulin. This study evaluated the effect of using CGM to reduce hyperglycemia, by focusing on food and lifestyle choices, in people with T2D not taking insulin. Methods: A 6-month randomized, prospective four-center study was conducted. The primary end point was a within-group reduction in time above range >180 mg/dL (TAR180) at 3 months. Participants were asked not to make diabetes medication changes in the first 3 months. Seventy-two adults not on insulin or sulfonylurea therapy, with glycated hemoglobin (HbA1c) 7.5%-12%, were randomized to use CGM alone (n = 31) or CGM plus a food logging app (n = 41) to aid diabetes management. Participants attended guided education visits. Differences in CGM metrics, HbA1c, and body weight were compared. Results: The CGM alone group decreased TAR180 from 55% at baseline to 27% at 3 months (P < 0.001) and 21% at 6 months (P < 0.001); the CGM plus food logging app group decreased TAR180 from 53% at baseline to 30% at both 3 and 6 months (P < 0.001 for both). For all participants, time in range (70-180 mg/dL) increased from 46% at baseline to 71% at 3 months (P < 0.001) and to 72% at 6 months (P < 0.001). HbA1c and weight were reduced by 1.3% (P < 0.001) and 7 pounds (lbs.) (P < 0.001) for all participants at 6 months. Conclusion: People with T2D not taking insulin showed large, clinically significant improvements in CGM metrics and HbA1c when using either CGM alone or with a food logging app. This occurred with a near absence of medication changes in the first 3 months and were therefore likely due to changes in food and/or lifestyle choices.

Continuous glucose monitoring among nurse practitioners in primary care: Characteristics associated with prescribing and resources needed to support use

BACKGROUND

Continuous glucose monitoring (CGM) can improve health for people with diabetes but is limited in primary care (PC). Nurse Practitioners (NPs) in PC can improve diabetes management through CGM, but NPs' interest in CGM and support needed are unclear.

PURPOSE

We describe behaviors and attitudes related to CGM for diabetes management among NPs in PC.

METHODOLOGY

This cross-sectional web-based survey of NPs practicing in PC settings used descriptive statistics to describe CGM experience and identify resources to support prescribing. We used multivariable regression to explore characteristics predicting prescribing and confidence using CGM for diabetes.

RESULTS

Nurse practitioners in hospital-owned settings were twice as likely to have prescribed CGM (odds ratio [OR] = 2.320, 95% CI [1.097, 4.903]; p = .002) than private practice; those in academic medical centers were less likely (OR = 0.098, 95% CI [0.012, 0.799]; p = .002). Past prescribing was associated with favorability toward future prescribing (coef. = 0.7284, SE = 0.1255, p < .001) and confidence using CGM to manage diabetes (type 1: coef. = 3.57, SE = 0.51, p < .001; type 2: coef. = 3.49, SE = 0.51, p < .001). Resources to prescribe CGM included consultation with an endocrinologist (62%), educational website (61%), and endocrinological e-consultations (59%).

CONCLUSIONS

Nurse practitioners are open to prescribing CGM and can improve diabetes management and health outcomes for PC patients.

IMPLICATIONS

Research should explore mechanisms behind associations with CGM experience and attitudes. Efforts to advance CGM should include educational websites and endocrinology consultations for NPs in PC.

Use of Glucose Monitoring Devices Among Adults with Diabetes in Germany: Results from Nationwide Surveys Conducted in 2017 and 2021/2022

Background: Devices for continuous glucose monitoring (CGM) have been developed to optimize blood glucose control and liberate people with diabetes from finger-prick glucose measurements. Since 2016, the devices have been reimbursed in Germany for people with diabetes receiving insulin therapy, resulting in their increased use among people with type 1 diabetes (T1D) and type 2 diabetes (T2D). We investigated the prevalence of CGM use and its associated factors among German adults with diabetes in 2017 and 2021/2022. Methods: Participants aged 18 years or older with diagnosed diabetes were identified from two nationwide population-based telephone surveys in 2017 (n = 1396) and 2021/2022 (n = 1456). Prevalence and dynamics of CGM use were examined overall and stratified by sociodemographic and diabetes-related characteristics. Factors associated with CGM use were obtained from logistic regression models. Results: The overall prevalence of CGM use was 8.2% in 2017 and 16.6% in 2021/2022. An increase in CGM use was observed across all the subgroups except for those without antidiabetic medications. CGM use increased from 31.1% to 75.4% in adults with T1D, from 6.3% to 13.6% in adults with T2D, and from 14.6% to 36.7% in all insulin users. In both surveys, younger age, insulin use, T1D, and reporting hypoglycemia were associated with CGM use. In addition, in 2017, higher education level and absence of obesity were associated with CGM use, whereas in 2021/2022, participation in the diabetes self-management education program and higher self-assessed quality of diabetes care were associated with CGM use. Conclusion: Among adults with diabetes in Germany, CGM use increased about twofold within 5 years, irrespective of sociodemographic factors. Educational inequality in CGM use diminished over time. The higher self-rated quality of diabetes care associated with the recent use of CGM provides further evidence to support its use among all adults with diabetes in Germany.

Exploring usability metrics in continuous glucose monitoring systems: insights from the voice of people with diabetes in Italy

Introduction

Continuous Glucose Monitoring (CGM) systems are crucial in diabetes management, offering clinical and psychological benefits despite operational challenges. Usability assessment of real-time and intermittently-scanned CGM systems is a notable research gap. This study, in collaboration with diabetes patient associations, explores CGM usability from the perspective of Italian individuals with diabetes.

Methods

A roundtable discussion with patient association representatives was conducted to discuss CGM usability, followed by a detailed online survey of 281 Italian patients on CGM usage, satisfaction, and feature preferences.

Results

Findings show a significant positive impact on Quality of Life (87/100) and moderate usability (66/100). Core CGM functions are widely used, while data sharing with healthcare professionals is underutilized. The study offers diverse insights into CGM usability from both the roundtable and survey data.

Conclusions

The study underscores the importance of CGM in diabetes management and highlights the need for continuous technological improvements. It emphasizes the role of patient associations in enhancing communication with manufacturers and CGM education. Effective collaboration between healthcare professionals and patients is vital for optimal CGM use, advocating for personalized care strategies tailored to individual patient needs.

Effect of introduction of intermittently scanned continuous glucose monitoring on glycaemic control in individuals living with type 2 diabetes mellitus treated with non-insulin therapies-A randomised controlled trial

AIMS

This pilot randomised controlled trial aimed to evaluate the effect of introducing isCGM on glycaemic control and diabetes distress in individuals with T2DM receiving non-insulin therapies.

MATERIALS AND METHODS

Forty adults with T2DM were randomised to either receive FreeStyle Libre 2 (Libre 2), an isCGM system, or FreeStyle Libre Pro iQ (Libre Pro) also known as 'blinded' CGM. Participants were followed for 12 weeks. The primary outcome was a fall in haemoglobin A1c (HbA1c) of ≥5.5 mmol/mol. Diabetes distress was assessed using the two-item diabetes distress scale (DDS2).

RESULTS

The median age was 59.5 years; 57.5% were male. Of the Libre 2 users, 53% achieved a ≥5.5 mmol/mol reduction in HbA1c compared to 35% in the Libre pro group (p = 0.34). Compared to Libre Pro, the use of Libre 2 was associated with an improved time in range at 12 weeks of 18 percentage points (confidence interval 2-35, p = 0.028). Participants in the Libre 2 group exhibited a non-significant reduction in HbA1c levels of 8 mmol/mol compared to the Libre Pro group after 12 weeks. However, no significant differences were observed in other CGM metrics or diabetes distress between the study groups.

CONCLUSIONS

The use of isCGM in individuals living with T2DM on non-insulin therapy showed promise in improving glycaemic control, as evidenced by increased TIR, albeit without a significant reduction in HbA1c or impact on diabetes distress, suggesting this could be potentially beneficial in individuals with T2DM.

7. Diabetes Technology: Standards of Care in Diabetes-2025

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

"Life with Diabetes": A Pilot Study on an Experiential Continuous Glucose Monitoring Curriculum for Resident Physicians

BACKGROUND

The use of technology in diabetes mellitus (DM) management has been growing. The indications and coverage for continuous glucose monitoring (CGM) have increased. Primary care (PC) clinics, including resident continuity clinics, are the frontline for DM management; however, they struggle to adopt CGM.

AIM

To implement a CGM curriculum to resident physicians to improve knowledge and confidence.

SETTING

An internal medicine (IM) resident PC clinic in an urban academic medical institution.

PARTICIPANTS

Twenty-four IM residents.

DESCRIPTION

We designed a curriculum that included a lecture about CGM indications, interpretation, ordering, and insurance consideration; and a voluntary, experiential learning module in which the residents wore a CGM.

EVALUATION

We conducted a retrospective pre-post survey with a 4-point Likert scale. Average self-reported scores in knowledge increased for CGM (1) indications from 1.85 to 3.45, (2) ordering from 1.35 to 3.05, (3) functioning from 2.20 to 3.50, and (4) data interpretation from 1.85 to 3.25 (all p < 0.0001). Confidence for "describing CGM monitoring" and "fielding questions about CGM" increased from 2.25 to 3.65 (p < 0.0001) and 1.90 to 3.30 (p < 0.0001).

DISCUSSION

Given the demand for DM management in the PC setting, this targeted CGM curriculum has promise to help residents adopt CGM into their practice.

Carbohydrate Ingestion Increases Interstitial Glucose and Mitigates Neuromuscular Fatigue during Single-Leg Knee Extensions

INTRODUCTION

We aimed to investigate the neuromuscular contributions to enhanced fatigue resistance with carbohydrate (CHO) ingestion and to identify whether fatigue is associated with changes in interstitial glucose levels assessed using a continuous glucose monitor (CGM).

METHODS

Twelve healthy participants (six males, six females) performed isokinetic single-leg knee extensions (90°·s -1 ) at 20% of the maximal voluntary contraction (MVC) torque until MVC torque reached 60% of its initial value (i.e., task failure). Central and peripheral fatigue were evaluated every 15 min during the fatigue task using the interpolated twitch technique and electrically evoked torque. Using a single-blinded crossover design, participants ingested CHO (85 g sucrose per hour), or a placebo (PLA), at regular intervals during the fatigue task. Minute-by-minute interstitial glucose levels measured via CGM and whole blood glucose readings were obtained intermittently during the fatiguing task.

RESULTS

CHO ingestion increased time to task failure over PLA (113 ± 69 vs 81 ± 49 min, mean ± SD; P < 0.001) and was associated with higher glycemia as measured by CGM (106 ± 18 vs 88 ± 10 mg·dL -1 , P < 0.001) and whole blood glucose sampling (104 ± 17 vs 89 ± 10 mg·dL -1 , P < 0.001). When assessing the values in the CHO condition at a similar time point to those at task failure in the PLA condition (i.e., ~81 min), MVC torque, percentage voluntary activation, and 10 Hz torque were all better preserved in the CHO versus PLA condition ( P < 0.05).

CONCLUSIONS

Exogenous CHO intake mitigates neuromuscular fatigue at both the central and peripheral levels by raising glucose concentrations rather than by preventing hypoglycemia.

Current landscape and comprehensive management of glycemic variability in diabetic retinopathy

Diabetic retinopathy (DR), a well-known microvascular complication of diabetes mellitus, remains the main cause of vision loss in working-age adults worldwide. Up to now, there is a shortage of information in the study regarding the contributing factors of DR in diabetes. Accumulating evidence has identified glycemic variability (GV), referred to fluctuations of blood glucose levels, as a risk factor for diabetes-related complications. Recent reports demonstrate that GV plays an important role in accounting for the susceptibility to DR development. However, its exact role in the pathogenesis of DR is still not fully understood. In this review, we highlight the current landscape and relevant mechanisms of GV in DR, as well as address the mechanism-based therapeutic strategies, aiming at better improving the quality of DR management in clinical practice.

Continuous glucose monitoring for glycaemic control and cardiovascular risk reduction in patients with type 2 diabetes not on insulin therapy: A clinical trial

AIM

To evaluate the impact of the Dexcom G6 continuous glucose monitoring (CGM) device on glycaemic control and cardiometabolic risk in patients with type 2 diabetes mellitus (T2DM) at high cardiovascular risk who are not on insulin therapy.

MATERIALS AND METHODS

Adults with T2DM with glycated haemoglobin (HbA1c) >7% and body mass index (BMI) ≥30 kg/m2 not using insulin were enrolled in a two-phase cross-over study. In phase 1, CGM data were blinded, and participants performed standard glucose self-monitoring. In phase 2, the CGM data were unblinded, and CGM, demographic and cardiovascular risk factor data were collected through 90 days of follow-up and compared using paired tests.

RESULTS

Forty-seven participants were included (44% women; 34% Black; mean age 63 years; BMI 37 kg/m2; HbA1c 8.4%; 10-year predicted atherosclerotic cardiovascular disease risk 24.0%). CGM use was associated with a reduction in average glucose (184.0 to 147.2 mg/dl, p < .001), an increase in time in range (57.8 to 82.8%, p < .001) and a trend towards lower glucose variability (26.2 to 23.8%). There were significant reductions in HbA1c, BMI, triglycerides, blood pressure, total cholesterol, diabetes distress and 10-year predicted risk for atherosclerotic cardiovascular disease (p < .05 for all) and an increase in prescriptions for sodium-glucose cotransporter 2 inhibitors (36.2 to 83.0%) and glucagon-like peptide-1 receptor agonists (42.5 to 87.2%, p < .001 for both).

CONCLUSIONS

Dexcom G6 CGM was associated with improved glycaemic control and cardiometabolic risk in patients with T2DM who were not on insulin. CGM can be a safe and effective tool to improve diabetes management in patients at high risk for adverse cardiovascular outcomes.

Continuous Glucose Monitor: Reclaiming Type 2 Diabetes Self-efficacy and Mitigating Disparities

Context

The rise in continuous glucose monitor (CGM) use has been characterized by widening disparities between the least and most socially marginalized. Given access barriers, there is limited CGM patient experience information that is inclusive of those with type 2 diabetes mellitus from socially marginalized backgrounds.

Objective

To understand the CGM usage experience in the primary care setting across a US Medicaid population with type 2 diabetes at federally qualified health centers.

Methods

This qualitative study used semi-structured phone interviews with 28 English- or Spanish-speaking participants prescribed the CGM who were enrolled in a US Medicaid program that subsidized CGMs. Audio recordings of interviews were transcribed and analyzed by reflective thematic analysis.

Results

Twenty-eight participants (75% female, median age 56 years with interquartile-range 48-60 years) were interviewed. Participants were from different racial/ethnic backgrounds: 21% non-Hispanic White, 57% Hispanic, and 18% non-Hispanic Black. Participants primarily spoke English (68%) or Spanish (32%), and 53% reported 9 or fewer years of formal education. We identified 6 major themes: initial expectations and overcoming initiation barriers, convenience and ease promote daily use, increased knowledge leads to improved self-management, collaboration with provider and clinical team, improved self-reported outcomes, and barriers and burdens are generally tolerated.

Conclusion

CGM use was experienced as easy to understand and viewed as a tool for diabetes self-efficacy. Expanded CGM access for socially marginalized patients with type 2 diabetes can enhance diabetes self-management to help mitigate diabetes outcome disparities.

Once-weekly insulin icodec versus once-daily long-acting insulins for type 2 diabetes mellitus: Systematic review and meta-analysis

Background

Insulin icodec is a novel, long-acting, once-weekly basal insulin analog. Its comparative efficacy and safety with basal once-daily insulins in type 2 diabetes mellittus is uncertain.

Objective

Evaluate potential efficacy, benefits and risks associated with icodec compared to once-daily basal insulin analogs (degludec or glargine).

Methods

We systematically searched PubMed, Cochrane, and Embase for randomized controlled trials (RCTs) published until June 2023 comparing icodec versus long-acting insulin analogs (degludec and glargine) in type 2 diabetes mellitus (T2DM) with at least 12 weeks of follow-up. Binary endpoints were assessed with risk ratios (RRs) and continuous endpoints were compared using mean differences (MDs), with 95% confidence intervals (CIs). The protocol was registered in PROSPERO (CRD42023452468).

Results

A total of seven RCTs and 3286 patients with T2DM were included, of whom 1509 (60.6%) received icodec treatment. The follow-up period ranged from 16 to 78 weeks. Compared with once-daily basal insulin analogs, icodec led to a greater improvement in HbA1c (MD -0.15%; 95% CI -0.21, -0.10; p < 0.0001; I2 = 0%) and time in range (TIR) (MD 2.83%; 95%CI 0.94; 4.71; p = 0.003; I2 = 22%). Body weight was increased with icodec treatment (MD 0.78 Kg; 95%CI 0.42, 1.15; p < 0.01; I2 = 86%). There was also a higher rate of injection site reactions (RR 1.89; 95%CI 1.12, 3.18; p = 0.016; I2 = 0%) and nasopharyngitis (RR 1.94; 95%CI 1.11, 3.38; p = 0.020; I2 = 0%) in the icodec group, compared with once-daily regimens. There was no significant difference between groups in fasting plasma glucose.

Conclusions

In this meta-analysis of RCTs, insulin icodec led to better control of HbA1c and TIR as compared with once-daily insulin regimens, albeit with increased weight gain and a higher rate of injection site reaction in the Icodec group.

The role of real-time continuous glucose monitoring in diabetes management and how it should link to integrated personalized diabetes management

Diabetes is a complex metabolic condition that demands tailored, individualized approaches for effective management. Real-time continuous glucose monitoring (rtCGM) systems have improved in terms of design, usability and accuracy over the years and play a pivotal role in the delivery of integrated personalized diabetes management (iPDM). iPDM is a comprehensive multidisciplinary approach that combines individualized care strategies utilizing technologies and interventions and encourages the active involvement of the person with diabetes in the care provided. The use of stand-alone rtCGM and its integration with other diabetes technologies, such as hybrid automated insulin delivery, have enabled improved glycaemic and quality of life outcomes for people with diabetes. As the uptake of rtCGM and associated technologies is increasing and becoming the standard of care for people with diabetes, it is important that efforts are focused on associated goals such as reducing health inequalities in terms of access, aligning structured education with rtCGM usage, choosing the right technology based on needs and preferences, and minimizing burden while aiming for optimal glucose outcomes. Utilizing rtCGM in other settings than outpatients and in diabetes cohorts beyond type 1 and type 2 diabetes needs further exploration. This review aims to provide an overview of the role of rtCGM and how best to link rtCGM to iPDM, highlighting its role in enhancing personalized treatment strategies.