Overcoming barriers in continuous glucose monitoring: Challenges and future directions in diabetes management

ABSTRACT

Recent updates on the efficacy of continuous glucose monitoring (CGM) and a critical examination of the current challenges in its implementation were summarized. The barriers to widespread adoption of this technology should be addressed, considering the impact of different cultural contexts. The strategies to overcome these obstacles and the benefits of CGM for future glucose management will be discussed.

Primary reasons for CGM discontinuation.

INTRODUCTION

Recent studies have consistently demonstrated the efficacy of CGM in improving glycemic control across both type 1 and type 2 diabetes populations. In adults with type 1 diabetes, the GOLD randomized clinical trial showed that CGM uses significantly improved glycemic control compared to conventional therapy, evidenced by better time‐in‐range and lower HbA1c levels ¹ . Similarly, a study in adolescents and young adults with type 1 diabetes found that CGM use over 26 weeks resulted in a modest yet significant reduction in HbA1c, supporting its role in enhancing glycemic management for this age group ² .

In hospitalized patients with diabetes, CGM‐guided insulin administration was shown to improve glycemic control compared to standard methods, with the potential for reduced hypoglycemia ³ . In adults with insulin‐treated type 2 diabetes, the Steno2tech study revealed that CGM use led to significantly improved glycemic control and time‐in‐range, outperforming traditional blood glucose monitoring ⁴ . Moreover, a meta‐analysis confirmed the positive impact of CGM on glycemic metrics in type 2 diabetes, highlighting its potential for broader application in managing this population ⁵ .

In gestational diabetes mellitus, CGM use has shown promising results, lowering maternal HbA1c (−0.22%, 95% CI −0.42, −0.03) and gestational weight gain, alongside reduced infant birth weight, compared to traditional glucometer. These findings emphasize its potential for improving both maternal and neonatal outcomes. Additionally, advanced hybrid closed‐loop systems integrating CGM with insulin delivery have significantly enhanced time in range, reduced hypoglycemia, and alleviated patient burden ⁶ .

EFFICACY OF CGM IN DIABETES‐RELATED COMPLICATIONS

Glycemic variability refers to the fluctuations in blood glucose levels, which is associated with an increased risk of hypoglycemia, microvascular and macrovascular complications, and mortality in individuals with diabetes ⁷ , ⁸ . CGM enables a more effective assessment of glycemic variability, which provides a comprehensive understanding of glycemic control. Time in range (TIR) refers to the percentage of time that glucose values remain within a target range. Higher TIR has been linked to a lower risk of albuminuria, retinopathy, cardiovascular disease mortality, all‐cause mortality, and abnormal carotid intima‐media thickness ⁷ . CGM also increases TIR, reduces time below range and time above range, and lowers glycemic variability ⁹ . However, CGM use does not significantly impact the incidence of severe hypoglycemia and macrovascular complications in patients with type 2 diabetes ⁹ .

Studies focusing on individuals with type 1 diabetes have demonstrated that lower TIR is associated with an increased occurrence of microvascular complications such as neuropathy, retinopathy, or nephropathy ¹⁰ . Furthermore, lower TIR is an independent risk factor for hospitalizations due to hypoglycemia or ketoacidosis ¹⁰ . In pregnant individuals with type 1 diabetes, higher TIR is associated with a reduced risk of preeclampsia and large‐for‐gestational‐age infants. Studies have shown that even small improvements in TIR can have a substantial positive impact on pregnancy outcomes ¹¹ . TIR, as a key indicator, has been shown to be associated with the reduction of risks for multiple complications. CGM not only provides more comprehensive glucose monitoring data but also helps improve glycemic control and reduces the risk of various diabetes complications.

These studies collectively underscore CGM's effectiveness in enhancing glycemic control, reducing HbA1c, and improving patient outcomes across both type 1 and type 2 diabetes. Since the approval of the MiniMed CGM in 1999 ¹² , its application in blood glucose control has been increasingly documented in the literature, gradually establishing its role as a cornerstone in modern diabetes management. Newer CGM models have demonstrated significant advancements in accuracy and patient acceptance, further solidifying their place in precision medicine and routine diabetes care.

With technological advancements, CGM use has become more widespread, offering substantial benefits in diabetes management. Studies have shown that early initiation of CGM can significantly enhance patient acceptance ¹³ . However, despite its proven effectiveness, several barriers to CGM adoption remain, preventing many patients from achieving optimal diabetes control and limiting its full potential to transform diabetes care.

THE HIGH COST OF CGM

In the United States, the qualifications for CGM reimbursement proposed by the Centers for Medicare & Medicaid Services fall significantly short of covering the diabetic population as supported by current evidence. Modifications to these qualifications to expand insurance coverage for CGM were suggested ¹⁴ . Similarly, in Asia, the reimbursement criteria for CGM for Taiwan, Japan, and South Korea are presented in Table 1.

Table 1.

Reimbursement criteria for continuous glucose monitoring (CGM) in Asia

Taiwan 33	Indications: Type 1 diabetes (holding a Catastrophic Illness Certificate), neonatal diabetes, or diabetes caused by near‐total pancreatectomy, and meeting any of the following conditions: Significant blood glucose fluctuations and two HbA1c values in the past 6 months greater than or equal to 8% Hypoglycemia unawareness Frequent severe hypoglycemia requiring assistance for treatment, with a record of emergency visits or hospitalization due to hypoglycemia in the past 3 months Pregnancy Pregnant patients with type 2 diabetes or gestational diabetes who are receiving insulin injections Glycogen storage diseases types 0, 1, 3, 6, or 9, with a history of severe hypoglycemia or continued use of cornstarch therapy
	Payment regulations: Outpatient use: Up to two applications per year with an interval of at least 1 month. If more than two applications are required within a year, prior approval is necessary Inpatient use: Prior approval is necessary. Up to two applications per year with an interval of at least 1 month Limited to medical institutions within the diabetes shared care network. Personnel performing the test, interpreting physicians, dietitians, and health educators must have completed training courses related to continuous glucose monitoring
Japan 34	Eligibility: ○ Patients who perform daily home injections of insulin preparations or insulin‐like growth factor C preparations ○ Patients with significant blood glucose fluctuations ○ Children under 12 years of age with hypoglycemia Medical management requirements: ○ Blood glucose management is conducted using an intermittently scanned continuous glucose monitoring (isCGM) system by a specialist physician or a full‐time physician with more than 5 years of experience in diabetes treatment Applicable conditions: ○ Nonhospitalized patients ○ Patients undergoing intensive insulin therapy ○ Patients who have previously undergone intensive insulin therapy and now use mixed insulin preparations at least twice daily Additional points: ○ Guidance based on blood glucose monitoring results ○ Add‐on points can be calculated up to three times every 3 months and included in the predetermined points
South Korea 35	Eligibility for coverage: Patients with type 1 diabetes who require insulin injections Comprehensive examination: When a continuous glucose monitoring (CGM) device is used for the first time, including electrode attachment and education on device usage, it can be calculated once. If the device model is replaced, an additional calculation is allowed General examination: After continuous use of the CGM device for a certain period (at least 14 days), when the attending physician reviews and interprets the recorded data, provides a written interpretation report, stores the data, and educates the patient on the examination results, it can be calculated up to six times per year

These stringent reimbursement criteria have been the primary reason CGM adoption remains limited.

Although CGM is relatively expensive, it may ultimately result in more cost‐effective outcomes if it can enhance the prevention of diabetes‐related complications. A systematic review indicated that CGM is a cost‐effective tool for type 1 diabetes, especially for those with poor blood glucose control or at high risk of hypo‐ or hyperglycemia ¹⁵ .

The high cost of CGM imposes a heavy financial burden on patients for long‐term use. However, a study demonstrated that even using CGM for just two weeks significantly improves six‐month glycemic control in patients with type 1 diabetes compared to those who only use glucometer ¹⁶ .

DISCOMFORT ASSOCIATED WITH CGM USAGE

Discomfort from wearing CGM has been identified as one of the main reasons for discontinuing its use. A study for type 1 diabetes revealed that, although CGM usage was associated with improved HbA1c levels, the primary reasons for discontinuation are outlined in Figure 1. These challenges remain unresolved and require further attention ¹⁷ .

Figure 1.

Primary reasons for CGM discontinuation.

INTERPRETATION OF CGM DATA

In clinical practice, the interpretation of CGM results should be done cautiously, as it may vary depending on the placement of the device. In an experiment involving 46 volunteers ¹⁸ , CGM devices were worn on both arms. Regardless of intermittent fasting or free eating, the average blood glucose levels on the right arm were consistently 3.7 mg/dL higher than those on the left arm.

INFORMATION OVERLOAD FROM CGM

In a study recruiting 111 patients, it was found that information overload negatively impacted the usability of CGM ¹⁹ . Moreover, people with diabetes who had never used CGM perceived a higher degree of information overload compared to the actual reports from current users. Therefore, they require more relevant information about CGM to alleviate their fears regarding its use.

BIAS AMONG HEALTHCARE PROVIDERS

Implicit biases among healthcare providers significantly impact patients' access to CGM‐assisted therapy. Among 109 healthcare providers, 66 (61%) were observed to have implicit biases related to insurance, while 37 (34%) exhibited implicit biases related to race/ethnicity ²⁰ . These biases can reduce patients' opportunities to access CGM, creating barriers to effective treatment.

PSYCHOLOGICAL CHANGES AND SOCIAL SUPPORT RELATED TO CGM USE

The use of CGM may cause psychological changes in the diabetic population and their families. Surprisingly, studies have indicated that adolescents using CGM may have a greater fear of hypoglycemia compared to those using a glucometer. Additionally, CGM‐using adolescents and their parents may exhibit more negative emotions compared to those in the glucometer group, leading to higher levels of anxiety and depression. However, this is the opposite in adults, where CGM users exhibit less anxiety compared to glucometer users. In summary, CGM users should be mindful of potential psychological changes to avoid negative impacts that may hinder glycemic control ²¹ .

In a 69‐week randomized‐controlled trial (including a 17‐week washout period) involving 161 patients randomly assigned to CGM or glucometer groups, it was observed that patients who used CGM for less than 70% of the time did not show significant improvements in HbA1c. This suggests that prolonged use of CGM may increase psychological stress on patients, leading to poorer glycemic control outcomes ¹ .

A study on type 1 diabetes to distinguish the psychosocial differences between those who benefited from CGM (Responders) and those who did not (Nonresponders) was conducted ²² . They found the following characteristics of Responders: Responders tend to approach frustrations as problems to be solved rationally; they use real‐time data for glycemic management and past data to adjust basal insulin doses and diet; their partners provide positive support for CGM use. However, both Responders and Nonresponders expressed concerns about the appearance of using CGM. Therefore, providing appropriate assistance to CGM users, encouraging them to fully utilize the data for blood glucose control, fostering companion support, and helping them face frustrations can enhance the benefits of CGM for glycemic management.

This demonstrates that CGM can impose not only physical but also psychological burdens on patients. Through adequate education by healthcare professionals and proper communication with patients, their psychological expectations regarding CGM can be addressed ²³ .

POTENTIAL BARRIERS IN DIFFERENT SETTINGS

Intensive‐care unit (ICU)

Whether CGM use is beneficial for ICU or non‐ICU patients and the existing barriers to its use are thoroughly discussed ²⁴ . Potential barriers include frequent use of acetaminophen in ICU patients, which is considered a significant factor interfering with CGM data interpretation. Intravascular CGM may lead to thrombosis formation, increasing the risk of catheter‐related infections. Additionally, since critical care teams primarily manage ICU patients, the lack of specialized training in CGM usage may result in incorrect interpretation of CGM values.

Currently, data on CGM use in non‐ICU hospitalized patients are relatively scarce compared to ICU settings. Although experts believe the advantages of CGM over conventional care are promising, there may still be unexplored barriers worth investigating. For instance, providing adequate training to healthcare personnel to correctly interpret CGM values remains essential.

Elderly population

Elderly people with diabetes account for a significant proportion of all diabetic population, making it crucial to address their use of CGM. Previous studies on self‐care among elderly people with diabetes have indicated that hand function can be a barrier to self‐care in this population ²⁵ . Additionally, long‐term diabetes‐related vision deterioration and age‐related learning difficulties in using CGM‐related applications may further increase the challenges for these patients in utilizing CGM effectively ²⁶ .

Gestational diabetes mellitus

CGM has been shown to help improve glycemic control in patients with gestational diabetes mellitus. However, there are still some barriers: for instance, acetaminophen and aspirin, which are commonly used during pregnancy, can interfere with sensor transmission. Additionally, due to the strict glycemic control required for gestational diabetes patients, the risk of hypoglycemia increases. However, the accuracy of CGM during hypoglycemic periods still needs improvement ²⁷ .

BURDEN ON CHILDREN AND THEIR CAREGIVERS

An article evaluating the sleep quality of 13 parents of children with type 1 diabetes using CGM showed similar perceived sleep quality before and after CGM use. However, sleep diaries indicated more frequent nighttime awakenings when using CGM, as well as an increase in total wake time, as recorded by actigraphy. Although subjective sleep quality did not change, it has been demonstrated that CGM may negatively affect sleep continuity, which is an important potential barrier to consider when using CGM ²⁸ .

CLINICAL EDUCATION FOR HEALTHCARE PROVIDERS

According to a study interviewing 31 diabetes educators, three major barriers to adopting new diabetes technologies were identified:

1. Accessibility of technology: This includes the lack of systematic processes to evaluate the benefits and trade‐offs of device usage for patients, the absence of commercial shared video systems, and difficulty accessing relevant applications.

2. Availability of support: This involves insufficient manpower to assist patients in using CGM and inadequate compensation for educators' efforts.

3. Rapid technological advancements: Educators face significant challenges in keeping up with the latest developments in devices and technologies. Moreover, incomplete information provided by patients adds to the difficulty, partly due to programming deficiencies ²⁹ .

Thus, new diabetes management technologies not only burden patients but also place additional strain on healthcare providers, warranting attention.

A survey conducted on 201 clinical diabetes care providers assessed their readiness to promote CGM and classified them into three groups ³⁰ .

1. Ready clinicians: These providers hold a positive attitude toward CGM, have sufficient time during consultations to assist patients, and keep up with technological advancements. They approach barriers, including cost‐related and noncost‐related issues, with a positive outlook.

2. Cautious clinicians: While they have a favorable attitude toward CGM, they believe they lack sufficient time to review CGM data during consultations. They also perceive the most significant barriers for patients, including financial and nonfinancial obstacles, among the three groups.

3. Not yet ready clinicians: This group has the most negative attitude toward CGM and new diabetes technologies. Keeping up with advancements poses a considerable challenge for them. Their patients are primarily adults, with the lowest proportion of type 1 diabetes cases and the lowest CGM usage rates. These clinicians mainly work in community hospitals and are older.

This highlights that some healthcare providers still lack confidence in new diabetes management technologies. Improving their understanding and providing sufficient education about CGM will be crucial for its future promotion.

PATIENTS NEED ASSISTANCE FROM HEALTHCARE PROVIDERS

Healthcare providers play a crucial role in assisting patients with CGM use. In an ongoing study, people with diabetes are divided into three groups: a routine care group, a group using a self‐directed digital integrated healthcare platform, and a group combining the digital platform, CGM, and feedback from healthcare providers ³¹ . The study observes changes in HbA1c over 6 months to determine whether combining CGM with healthcare provider support improves HbA1c outcomes. The results are yet to be validated.

It has already been confirmed that several measures can help improve traditional glucometer adherence, including problem‐solving, contingency management, goal‐setting, cognitive behavioral therapy, etc. However, no confirmed strategies currently exist to improve adherence to CGM use ³² .

CONCLUSION

With technological advancements, CGM has brought significant benefits to blood glucose management. However, it also comes with challenges that need to be addressed, such as the high cost of CGM, discomfort from wearing the device, the interpretation of large amounts of CGM data, psychological changes caused by CGM use, biases among healthcare providers, and insufficient clinical education for medical staff. These are issues that must be tackled in the future.

DISCLOSURE

JIANG, YI‐DER is an Editorial Board member of JOURNAL OF DIABETES INVESTIGATION and a co‐author of this article. To minimize bias, they were excluded from all editorial decision‐making related to the acceptance of this article for publication.