Among the remarkable advances in diabetes technology witnessed by the diabetes community in the past decade, continuous glucose monitoring (CGM) stands out as a game-changer. Let’s examine its transformative impact in depth.
What is continuous glucose monitoring (CGM)? What’s its significance?
CGM involves continuously tracking blood glucose (sugar) levels throughout the day and night using an automatic device. It provides real-time data about your glucose levels at any point in time or how they fluctuate over a few hours or days and helps spot trends.
This real-time tracking lets you make informed decisions about your diet, physical activity, and medications. Additionally, maintaining blood glucose levels within a target range can help prevent other long-term complications caused by diabetes, such as heart disease and kidney damage.
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CGM Vs. SMBG (Self-monitoring blood glucose)
Self-monitoring of blood glucose (SMBG) is a traditional method that involves a fingerstick test to measure blood glucose levels at a single point in time. In contrast, continuous glucose monitoring (CGM) continuously tracks glucose levels, providing detailed trends and patterns. Let’s understand the key differences in diabetes management between CGM and SMBG.
A.Glucose Measurement
-SMBG- Measures glucose levels in the blood
-CGM-Measures glucose levels in the fluid between your cells (interstitial fluid)
B. Measurement frequency
-SMBG-Provide glucose readings at a single point in time
-CGM-Provide continuous glucose readings throughout the day and night
C. Sampling method
-SMBG-Requires fingerstick tests multiple times a day
-CGM-Requires sensor insertion under the skin. Minimizes fingerstick tests by continuous glucose tracking
D. Data indicators
-SMBG-No capability for alerts and alarms
-CGM-Provides customizable alerts for high/low glucose levels, trend graphs, rate of glucose change, and predictive warnings
E. User Involvement
-SMBG-Requires manual testing and logging
-CGM-Automatically tracks glucose levels with minimal user input
F. Precision
-SMBG-Reliable for single glucose reading but may not capture glucose fluctuations
-CGM-Reliable for tracking glucose patterns, but may have slight delays in reflecting rapid glucose changes (lag time)
G. Clinical utility
-SMBG-Suitable for initial diagnosis and monitoring of diabetes
-CGM-Ideal for optimizing insulin therapy, detecting glucose patterns, and preventing episodes of hypoglycemia
How does CGM work?
A continuous glucose monitor system comprises three parts: sensor, transmitter, and receiver.
-Sensor: It is a tiny device inserted under the skin, typically on the arm or belly. There are two types of sensors: disposable and implantable. Disposable sensors are intended for single use and are inserted under the skin using a sticky patch that helps them keep in place. Implantable sensors are surgically placed under the skin. The sensors need to be changed periodically, depending on the sensor type you use. Both types of sensors estimate the glucose level in the fluid between your cells, which is very similar to the glucose level in your blood.
-Transmitter: It sends information to the receiver wirelessly and may include features like alarm notifications and data storage.
-Receiver: It is integrated with a smartphone, insulin pump, or a separate device and displays real-time glucose data, trends, and historical records. It also provides alerts and alarms for high or low glucose levels, rate of glucose value change, and other predictive warnings.
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Who can benefit from CGM?
The American Diabetes Association (ADA) Standards of Care, 2024 recommends:
-Early use of CGM, even at diagnosis, for adults with Type 1 diabetes to improve blood sugar control, minimize hypoglycemia, and enhance quality of life.
-Adults with diabetes who use basal insulin should be offered real-time (rtCGM) or intermittently scanned (isCGM) CGM systems, provided they can use them safely, independently, or with help. The choice of device should be based on the individual’s circumstances, preferences, and needs.
What are the key features of CGM?
Whether working, exercising, or sleeping, CGMs are always on and recording glucose levels when worn. Their key features include:
A. Hardware Features-
-A small, wearable sensor that can be placed under the skin
-Wireless connectivity (Wi-Fi, Bluetooth-based)
-Rechargeable batteries and replaceable sensors
-Water resistance (varies from brand to brand)
B. Data Features-
-Continuous, real-time, retrospective glucose level estimation
-High or low glucose level alerts
-The trend arrows and graphs indicate if glucose levels have increased, decreased, or remained steady.
-Predictive warnings (e.g., sudden spikes in glucose levels)
C. Integration features-
-Compatible with multiple devices like smartphones, tablets, fitness trackers, etc.
-Integration with insulin pumps, smart insulin pens
D. Advanced features-
-Calculate insulin doses with a built-in bolus calculator
-Remote glucose monitoring and data sharing directly with caregivers or doctors
What are the benefits of CGM?
Compared to traditional glucometers, using a CGM:
-Provides 24/7 glucose monitoring, revealing patterns and trends.
-Provides real-time alerts for high or low blood glucose levels, predictive warnings, or rate of glucose variability.
-Minimizes painful fingerstick tests.
-Informs about insulin dosing, meal planning, exercise, and lifestyle adjustments.
-Fosters informed health decisions.
Remember!
Over time, keeping your glucose levels in the healthy range can help you stay well and prevent diabetes complications. Continuous glucose monitoring (CGM) is empowering individuals with diabetes to take control of their condition like never before. By providing real-time data and comprehensive glucose insights, CGM technology enables informed treatment decisions, improves glucose control, and enhances overall quality of life. As technology advances, we can expect more innovative features to emerge.
(The article is written by Dr. Lipika Khurana, Deputy Manager, Diagnostic Content , and reviewed by Dr. Sakshi Jain, Senior Manager, Clinical Health & Content)
References-
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