Continuous Glucose Monitoring: What Is It? How Does It Work?

by Yi-Ping Chen

To better control your blood sugar, self-care practices and assessment of sugar levels play important roles in addition to balanced diet, regular exercise, and medication.

Monitoring blood sugar levels helps you and your healthcare providers identify the patterns in the fluctuation of blood sugar levels. Aside from finger prick, Continuous Glucose Monitoring (CGM) also allows you to track your blood sugar levels throughout the day. Compared to the traditional methods, CGM is more effective in helping people detect hypoglycemia or sugar spikes that may go unnoticed.

Healthcare providers can then identify the reasons behind patients’ fluctuation in blood sugar levels and suggest the necessary adjustments to stabilize their blood sugar levels.

So, how is Continuous Glucose Monitoring (CGM) different from the traditional blood sugar monitoring methods? Let’s delve in!

A Continuous Glucose Monitoring device is about the same size of two stacked quarters and is composed of a sensor and a transmitter. The sensor is inserted directly under the skin, usually on the arm, and the small tube will pierce through the top layer of the skin and measure the glucose in the interstitial fluid.

This allows patients to see their blood sugar levels represented as a line chart rather than dots on a graph. Since glucose in the capillaries diffuses freely into the interstitial fluids, the sensor in the interstitial fluids can detect the glucose in order to monitor the users’ blood sugar levels.

Compared to the traditional blood monitoring method, CGM provides more detailed blood sugar data and information, forming blood sugar curve graphs that allow users to observe how their blood sugar levels changes over time. Moreover, doctors can examine the curve graphs to identify blood sugar spikes or hypoglycemia that can go unnoticed using the traditional methods and make more accurate diagnosis.

What Are the Different Types of CGM?

Professional CGM

Professional CGM is the most commonly used ones at hospitals. It records blood sugar levels every 5 minutes, resulting in 288 records per day. Healthcare professionals cannot view the data in real-time. The data is stored in the device and uploaded from the device to the healthcare professional’s computers for further analysis during the next appointment.

Since patients cannot see their blood sugar levels fluctuating in real-time, they’re less likely to intentionally change their lifestyle habits. Nonetheless, professional CGM, when combined with proper documentation of diet, activities, and medication, makes it easier to pinpoint the factors affecting blood sugar changes.

It’s also important to note that it’s still recommended to conduct finger prick 3 – 4 times a day to provide calibration references for healthcare professionals during consultation.

Intermittently Scanned CGM

Intermittently scanned CGM is one of the common personal CGM available for daily use. The system consists of a sensor that will last for 14 days and a reader, usually a mobile phone with a dedicated scanning app. When using the intermittently scanned CGM, simply scan the sensor attached to your arm using the app and you will be able to see the glucose level in the interstitial fluid. This allows the users to immediately adjust their diets, activities, or lifestyle habits to stabilize their blood sugar levels.

Real-Time CGM

Depending on your location, you may be able to purchase real-time CGM at pharmacies or clinics. You can view real-time blood sugar trends on mobile devices, such as smartphones, tablets, and smartwatches, when using real-time CGM.

This type of CGM is particularly useful for those who need more comprehensive blood glucose data for better blood glucose management and don’t get overwhelmed by real-time blood sugar changes.

After checking the real-time blood sugar level, users can make adjustments, whether it’s diets, medication, or other activities, and see how those changes will affect their blood sugar levels right away. In addition, real-time CGM can send alerts for hypoglycemia 10 – 60 minutes before it happens so that users can prevent hypoglycemia, avoid blood glucose spikes caused by over-compensating, and minimize the harm that hypoglycemia can cause.

Under What Situations Is CGM Recommended for Patients with Diabetes?

As explained in the previous sections, we can see that Continuous Glucose Monitoring (CGM) devices live up to the name by allowing us to observe how our blood sugar levels fluctuate continuously rather than viewing them as isolated data points on a chart. This helps to identify causes and patterns in blood glucose variations that may go unnoticed with SMBG. CGM is therefore particularly helpful for the following individuals:

  1. Individuals with type 1 or type 2 diabetes with poor glycemic control
  2. Those who are worried about nocturnal hypoglycemia or have frequent hypoglycemia episodes
  3. Individuals whose HbA1c values don’t match with their fingertip glucose levels
  4. Individuals whose blood sugar levels fluctuate drastically
  5. Those with pre-diabetes who aim to reverse it through dietary or lifestyle changes
  6. Individuals who still have high blood sugar levels even though they’ve made dietary adjustments
  7. Pregnant women with gestational diabetes or those concerned that high blood sugar might affect their babies

CGM Helps Understand Blood Sugar Fluctuations More

After using CGM, users will discover that even though they might have the same HbA1c value, their glycemic variability, or the degree of blood sugar fluctuations, can be quite different.

Some people with diabetes have minimal blood sugar fluctuations, like a slowly moving train, but have average blood sugar levels. Others might have relatively lower average blood sugar levels, but their blood glucose levels might go up and down like a roller coaster, which increases the risks for cardiovascular complications. In addition, individuals experiencing frequent hypoglycemic episodes should remain cautious as the average blood sugar may be deceptively low.

The greater the glycemic variation, the more damage it causes to blood vessels, increasing the risk of other complications. As a result, in clinical practices, there is growing emphasis on monitoring blood glucose variability, making it an important indicator for preventing diabetes complications.

Continuous Glucose Monitoring (CGM) has had a profound impact on diabetes management, helping patients to identify the causes of their blood sugar fluctuations and adjust their diets or activities accordingly. Moreover, it has also allowed healthcare professionals to provide more accurate dietary recommendations and medication adjustments to lower the risk for complications of diabetes.

However, it’s important to note that while CGM devices provide more data for analysis, consistent self-care, diet control, and exercise are still the most crucial aspects for keeping your blood sugar levels stable.

Download Health2Sync Now!

Related Posts