‘Patients benefitting from continuous glucose monitors see a big difference’

It's no secret that diabetes patients need constant care to prevent complications. This is especially true in Korea where one in six adults over 30 has diabetes.

That, in turn, means it is crucial to measure blood glucose to identify patterns of blood glucose fluctuations and improve overall lifestyle habits, including medication, diet, and exercise. This is where continuous glucose monitors (CGMs) come into play. CGMs have made it easier than ever for people with diabetes to check their blood glucose levels at any given time and create a personalized diabetes management plan accordingly.

Korea Biomedical Review interviewed Professor Song Kee-ho of the Department of Endocrinology and Metabolism at Konkuk University Medical Center, to listen to the efficacy of CGMs and their effectiveness in blood glucose management in clinical practice.

Question: Recently, continuous glucose monitors (CGMs) have been introduced and used in Korea for diabetes management. How are CGMs used in clinical practice for patients in Korea?

Answer: For patients with type 1 diabetes, continuous glucose monitors have been used a lot recently as insurance covers their use. In particular, younger people and those who have used them once have continued to use them. It seems that CGMs have become somewhat established among type 1 patients.

People with type 2 diabetes who take insulin also benefit from using CGMs (to manage their diabetes), but they are not yet as widely used as those with type 1.

Q: People with diabetes face challenges managing their condition due to different blood glucose fluctuations and treatments. What are the benefits of CGMs for diabetes management and how do they differ from traditional self-monitors?

A: In diabetes management and glycemic control, the most common metric we look at is glycated hemoglobin. It's an average of your blood sugar over three months, and most guidelines have been about how low or how high you should control it.

The problem with measuring HbA1c is that it's an average of two to three months. Blood sugar fluctuates depending on what you eat before and after meals, what you eat, and whether you exercise or not. And while a traditional glucose meter allows you to check your blood sugar when you want to, it's a snapshot in time, so you don't know how your blood sugar is changing.

A continuous glucose monitor, on the other hand, shows you your blood sugar fluctuations throughout the day. You can see all the changes in your blood sugar in response to food, activity, and exercise. This means you're seeing real blood sugar changes.

With continuous glucose monitoring, you can see these numbers for yourself and realize that this diet or exercise is working for you, or that it's not working as well as you thought it would, which gives you more control.

For people with type 1 diabetes who need to take insulin, CGMs are also useful for adjusting insulin doses. For those who use an insulin pump, it's much easier to calculate insulin doses based on the amount of food they eat by linking the meter to the pump.

Q: CGMs are recommended in the American Diabetes Association's (ADA) 2024 standard of care guidelines. What about the Korean guidelines?

A: The American Diabetes Association's guidelines state that people with type 1 diabetes should use a CGM. Not using a CGM is considered suboptimal care. People with type 2 diabetes are also advised to use CGMs if they take insulin.

Korean guidelines also recommend in 2024 that people with type 1 diabetes should use CGMs, which means that continuous glucose monitoring is the standard of care for people with type 1 diabetes in Korea.

Q: Which patients should be prioritized for the use of CGMs?

A: People with type 1 diabetes should use one. Type 1 diabetes is characterized by high blood glucose fluctuations and a high risk of hypoglycemia. People with type 1 diabetes who take insulin and are prone to hypoglycemia can use a CGM to track their blood sugar levels.

In recent years, there has been a movement to use CGMs to control blood sugar in patients with gestational diabetes and type 2 diabetes, who need to keep their blood sugar under strict control, even if they are on medication. This will broaden the use of CGMs.

Q: There are many different CGMs on the market today. What are the benefits of these new features, including alarms, for diabetes management?

A: One of the advantages of using a CGM is the ability to predict and prepare for hypoglycemia. The alarm feature gives you time to prepare for a low blood sugar episode.

If you experience low blood sugar repeatedly and frequently, you may become so accustomed to low blood sugar that you don't even notice the symptoms of hypoglycemia. This can lead to serious conditions, including confusion, seizures, and coma, which can occur suddenly without warning. The alarm function of a CGM can prevent this from happening, which is a great advantage.

In addition, patients with hypoglycemic insensitivity are often anxious about when they will have low blood sugar, and the alarm function of a CGM can help alleviate that anxiety.

Q: Despite the benefits of CGMs, only about 10.7 percent of people with type 1 diabetes in Korea use them. What are the reasons for the slow spread of CGMs, and what can be done to increase their use?

A: CGMs used to be expensive in the past but now they've come down in price, which explains the low uptake of CGMs. I wonder if the low usage rate is due to patients' reluctance to attach something to their body and to get used to a new device.

It may also be a matter of compromise. When people are used to having diabetes and are less alert, they don't listen to doctors' recommendations. They tell you that you need to control your blood sugar below a certain level, but people with type 1 diabetes don't follow that recommendation because they're used to it, whether it's 200 mg/dL or 300 mg/dL.

To prevent this from happening, it's important to start using CGMs early in the diagnosis of diabetes to get used to them. Patients then take it for granted and are much better at using CGMs because they realize right away that it makes it easier to control their blood sugar.

Q: What are the challenges of recommending the use of CGMs?

A: Some people know they need to take control of their diabetes but don't do so. They don't listen to the best advice. Doctors have to raise their awareness, and it's not always easy to spend a lot of time explaining and convincing each patient in detail. It's not easy to change people.

However, many people have improved their glycemic control with CGMs, so it's important to educate them more and make it a habit through experience.

Q: How will diabetes management change in the future?

A: We will increasingly rely on technology, including AI. We have reached the point where we link an insulin pump to CGM to make it almost like an artificial pancreas. There will be a lot of help from technology, but the most important thing is lifestyle change. We must find ways to change their lifestyle.

One of the ways to change habits is to use a CGM. Motivated people change drastically after they use a CGM to see their blood sugar change.