The Role of Continuous Glucose Monitoring (CGM) in Pediatric Diabetes Management

What is continuous glucose monitoring (CGM)?

Continuous Glucose Monitoring (CGM) is an advanced technology that continuously tracks blood glucose levels throughout the day and night. Unlike traditional fingerstick tests that provide isolated readings, CGM devices offer a constant stream of real-time data. This allows for the identification of glucose level patterns and trends, enabling more informed diabetes management decisions.

CGM is particularly beneficial for children with type 1 diabetes, as it:

• Reduces the need for multiple daily fingerstick tests
• Provides immediate alerts for high or low glucose levels
• Enhances parental confidence in managing their child's diabetes

By continuously monitoring glucose levels, CGM helps children and their caregivers make timely adjustments to insulin dosing, diet, and physical activity, ultimately leading to better glycemic control and quality of life.

What is interstitial fluid?

Interstitial fluid is the fluid found in the spaces between cells in the body. It is part of the extracellular fluid compartment and is vital in transporting nutrients and waste products between the cells and the bloodstream. In the context of CGM, the CGM sensor is inserted under the skin into the interstitial fluid. The sensor measures the glucose concentration in this fluid, which closely correlates with blood glucose levels. By detecting changes in interstitial glucose, CGM devices can provide a continuous stream of data that reflects overall glycemic control.

Understanding the role of interstitial fluid is crucial for CGM users. It explains the slight delay between blood glucose changes and the readings displayed on the CGM device. This delay, typically around 5-10 minutes, occurs because glucose takes time to move from the bloodstream into the interstitial fluid.

How does a continuous glucose monitor (CGM) work?

A Continuous Glucose Monitor (CGM) works by using a small sensor inserted under the skin to measure glucose levels in the interstitial fluid. Here's a step-by-step breakdown of how CGM devices function:

• Sensor insertion: A tiny electrode, called a CGM sensor, is inserted just under the skin, usually on the abdomen or arm. This sensor measures glucose levels in the interstitial fluid every few minutes, typically every 5 minutes.
• Data transmission: The CGM sensor wirelessly transmits the glucose data to a display device, which can be a dedicated receiver, a smartphone, or a smartwatch. This allows users and their caregivers to monitor glucose levels in real time.
• Real-time readings and trends: The display on a CGM shows the current glucose reading along with trend arrows indicating whether the glucose level is rising, falling, or stable. This real-time data helps identify immediate changes and patterns in glucose levels, enabling timely interventions.

Many parents find the trend arrows in a CGM helpful in managing their child's diabetes. For example, suppose the arrow points upward, indicating a rising glucose level. In that case, they may choose to administer a corrective dose of insulin or encourage their child to engage in physical activity to prevent hyperglycemia.

• Alerts and notifications: Most CGM devices offer customisable alarms and notifications that alert users when their glucose level is too high or too low. These alerts on a CGM can be set up to notify caregivers remotely, which is especially useful for young children who may not recognise the signs of hyper- or hypoglycemia themselves.
• Integration with insulin therapy: CGM can be used alongside insulin pumps as part of sensor-augmented pump (SAP) therapy or with multiple daily injections. Some systems are fully integrated, displaying CGM readings on the pump's screen. Advanced systems, like the Medtronic Paradigm Veo, include features such as low glucose suspend, which halts insulin delivery when glucose levels drop below a preset threshold.
• Retrospective analysis: CGM data can be analysed retrospectively to understand patterns of glucose levels at different times of the day or in response to various foods and activities. This CGM information helps in adjusting diabetes management routines, such as diet and insulin dosing, to achieve better glycemic control.

Did you know? Studies have shown that consistent use of CGM can improve haemoglobin A1c (HbA1c) levels and reduce the time spent in hypoglycemic ranges, especially when used frequently (at least 6 days a week).

Are CGMs easy to use?

CGM devices are generally designed to be user-friendly, particularly for children and their caregivers. Here are some aspects that make a CGM relatively easy to use:

• Simple sensor insertion: The process of inserting the CGM sensor is straightforward and can be done at home. Many devices come with automated insertion tools to make this step easier.
• Real-time data: The real-time glucose readings and trend arrows on a CGM provide immediate feedback, allowing users to make quick and informed decisions about their diabetes management. This reduces the reliance on frequent fingerstick blood glucose tests.
• Customisable alerts: Parents and caregivers can set up CGM alerts and notifications to ensure they are promptly informed if their child's glucose levels are outside the target range. This adds a layer of security and reduces the stress associated with managing diabetes.
• Compact and discreet design: CGM devices are designed to be small, discreet, and easy to wear, making them suitable for children. Some devices, like the Senseonics Eversense, feature long-lasting implantable sensors that reduce the need for frequent sensor changes.

However, despite these advantages, there are still some challenges to consider, such as the need for regular CGM sensor replacements, charging the transmitter and display device, and addressing any skin irritation caused by the adhesive. With proper education and support from healthcare providers, these challenges can be easily managed, allowing children and their families to benefit from CGM technology fully.

Do we still have to do fingerstick checks while using a CGM?

While continuous glucose monitoring significantly reduces the need for fingerstick checks, they are not entirely eliminated. CGM devices measure glucose levels in the interstitial fluid, which can lag behind blood glucose levels by 5-10 minutes. Fingerstick checks are still necessary for calibrating the CGM sensor and confirming readings, especially during rapid glucose changes or when CGM readings seem inconsistent.

For example, if a child's CGM device alerts them to a low glucose level, a fingerstick check can provide an immediate and accurate blood glucose measurement. This helps determine if treatment, such as consuming fast-acting carbohydrates, is necessary. Additionally, some clinical situations, like illness or questionable CGM readings, may require extra fingerstick checks to ensure the CGM sensor is functioning properly and providing reliable data.

Can people without diabetes use a CGM?

Continuous glucose monitoring is specifically designed for individuals with diabetes, particularly those with type 1 diabetes and some with type 2 diabetes who require intensive glucose management. There is no established medical need or benefit for people without diabetes to use a CGM device. The technology is tailored to help manage and control blood glucose levels, which is not a concern for individuals without diabetes.

What are the advantages of using a CGM to manage diabetes?

Using a continuous glucose monitoring system offers several significant advantages in managing pediatric diabetes:

• Improved Glucose Control: CGM devices provide a continuous stream of glucose readings, helping children and their caregivers identify patterns and trends. This leads to better diabetes management and can lower HbA1c levels, particularly when used consistently (at least 6 days a week). For instance, if a child's CGM sensor reveals consistently high glucose levels after meals, adjustments can be made to insulin dosing or meal planning.
• Reduced Risk of Hypoglycemia: CGM alerts users and their caregivers to impending hypoglycemic episodes through customisable alarms and notifications, allowing for timely intervention. This feature is particularly beneficial for young children who may not recognize or communicate their symptoms. A study found that CGM use reduced the time spent in hypoglycemia by 48% compared to fingerstick monitoring alone.
• Enhanced Parental Comfort and Sleep: For parents, CGM devices offer peace of mind by providing real-time glucose data, reducing the need for overnight fingerstick checks and improving sleep quality. Remote monitoring capabilities also make it easier for other caregivers to be involved in diabetes management. Imagine being able to check your child's glucose levels from your smartphone, even when they're at school or with friends.
• Increased Awareness and Understanding: Continuous glucose monitoring helps children and their caregivers understand how different activities, foods, and times of day affect glucose levels. This information can be used to modify diabetes management routines and make more informed decisions about insulin dosing, diet, and physical activity. For example, if a child's CGM sensor shows a consistent glucose spike after soccer practice, adjustments can be made to pre-exercise snacks or insulin.
• Integration with Insulin Therapy: CGM devices can be used with insulin pumps as part of sensor-augmented pump (SAP) therapy or with multiple daily injections, enhancing the effectiveness of insulin treatment. Some systems include features like low glucose suspend, which can halt insulin delivery when glucose levels drop to a preset threshold. Studies have shown that SAP therapy with CGM improves glycemic control and reduces hypoglycemia in children with type 1 diabetes.

Do we need a CGM to manage diabetes?

While a CGM is highly beneficial for managing diabetes, it is not a necessity for all patients. Traditional self-monitoring of blood glucose (SMBG) can still be effective, especially for those who do not have access to CGM technology due to various barriers such as cost, health system limitations, or socioeconomic disparities. However, for many patients, particularly children with type 1 diabetes, CGM devices can offer significant improvements in glycemic control, reduction in hypoglycemia, and enhanced quality of life.

What are the limitations of CGMs?

While continuous glucose monitoring offers numerous benefits, it's important to be aware of its limitations:

• Calibration Requirements: CGM devices need periodic calibration with fingerstick blood glucose measurements to ensure accuracy. This can be inconvenient and may not always align perfectly with blood glucose levels, especially during rapid changes.
• Sensor Duration: The CGM sensors used have a limited lifespan, typically ranging from 3 to 14 days, depending on the manufacturer. This requires regular replacements and can be a logistical challenge.
• Cost and Accessibility: CGM technology can be expensive and may not be accessible to all patients due to socioeconomic disparities, insurance coverage issues, or geographic barriers to healthcare services.

What are the drawbacks of CGMs?

In addition to the limitations mentioned above, there are some potential drawbacks to using a CGM device:

• Skin Irritation: Some children may experience skin irritation or allergic reactions to the adhesive used to attach the CGM sensor. This can cause discomfort, redness, or itching at the insertion site.
• Data Overload: The continuous stream of glucose data provided by CGM devices can sometimes feel overwhelming for children and their caregivers. It's important to work with your healthcare team to set realistic expectations and develop a plan for using the information effectively.
• False Alarms: While CGM alarms are designed to alert users to high or low glucose levels, false alarms can occur. This can be disruptive, especially at night, and may lead to alarm fatigue over time.

When to see a doctor?

If you're considering continuous glucose monitoring for your child, it's important to discuss the option with your pediatric endocrinologist. Additionally, if your child is experiencing frequent hypoglycemic episodes, difficulty managing glucose levels, or other diabetes-related concerns, it's crucial to consult with your healthcare team. They can review your child's CGM data, make adjustments to their diabetes management plan, and provide ongoing support.

Can you get a CGM without a doctor?

CGM devices require a prescription from a healthcare provider. They are not available for purchase over the counter, as they are considered medical devices that require proper training and guidance for use. Your child's pediatric endocrinologist or diabetes care team will work with you to prescribe an appropriate CGM system and provide education on how to use it effectively.

Conclusion

Continuous Glucose Monitoring (CGM) has revolutionised pediatric diabetes management by providing real-time, actionable data on glucose levels. By understanding what CGM is, how CGM sensors work, and the benefits of using CGM devices, children with diabetes and their caregivers can make informed decisions to optimize glycemic control and improve overall quality of life.

At Metropolis Healthcare, we understand the importance of accurate and timely diagnostic information in managing chronic conditions like diabetes. Our team of skilled phlebotomists provide convenient at-home blood collection services, ensuring your child's samples are processed in our state-of-the-art laboratories. With our user-friendly Metropolis TruHealth app, you can easily access your child's test reports and track their progress over time.