What does "Time in Range" (TIR) ​​mean for you who have diabetes? Let's find out exactly!

Do you have diabetes? Or does someone in your family or a friend have diabetes? Then you may have heard, or maybe your doctor has talked about this thing called 'Time in Range'. So, let's talk about it simply and clearly today. Although this is a bit new, it is something that helps a lot in controlling diabetes.

What is this "Time in Range" (TIR)?

Simply put, “Time in Range” (TIR) ​​is the amount of time a person with diabetes can keep their blood sugar (glucose) levels within a certain target range . Imagine your doctor telling you to keep your blood sugar levels between this range and this range. This measures how long you stay within that range.

For most people with diabetes, both those with Type 1 Diabetes and adults with Type 2 Diabetes, this target range is usually between 70 and 180 milligrams per deciliter (mg/dL) . But this is not the same for everyone, and it can vary from person to person. TIR is measured as a percentage . Doctors usually say to try to keep your TIR above 70% . That means your blood sugar should be in that range for at least 17 hours out of 24 hours a day. That's when you can consider your diabetes well-controlled.

How do you measure this TIR accurately?

The easiest and most accurate way to find out your TIR is to use a Continuous Glucose Monitor (CGM) . You may have heard of this device before. It is actually a small wearable device that is placed under the skin of your arm or stomach . While you are wearing it, it continuously measures and records the glucose levels in the interstitial fluid under your skin 24 hours a day. It is like a little detective who is looking for your sugar. You can then download this glucose data using software that is connected to the CGM device or an app on your phone and track your TIR.

Actually, you can get a rough idea of ​​your TIR by doing a manual finger prick . But if you do that, you have to check your blood sugar several times a day . Even then, it doesn't provide as much detailed data as a `CGM`. Think of it like flipping through the pages of a book. But a `CGM` is like reading the whole book! It gives you a complete picture of your blood sugar levels.

Because of these `CGM` machines, many people with diabetes and their doctors are now using this TIR to help them manage their diabetes.Accurately assess your TIR data. By looking at your TIR data, you and your doctor can set new goals and make necessary changes to your treatment plan.

What does this TIR report look like?

In these TIR reports, which come from the software on CGM machines, the different ranges of your sugar levels are usually shown as a colored vertical bar . It's very easy to understand.

• The time your sugar level was in-range is shown in green . This is what we all strive to improve.
• Other ranges, meaning times when sugar levels are low or high, are shown in other colors like yellow, orange, and red .

Here's how these ranges are displayed on a typical `CGM` report (from bottom to top):

• Less than 54 mg/dL (< 54 mg/dL) — Very low (below target). This will appear red. This can be a dangerous situation.
• Between 54 mg/dL and 69 mg/dL — Low (below target). This may look orange. This is also an area to pay attention to.
• Between 70 mg/dL and 180 mg/dL — in-range. That's what's in green . We're all trying to make this green part bigger!
• Between 181 mg/dL and 250 mg/dL — high (above target). This looks like yellow.
• Greater than 250 mg/dL (> 250 mg/dL) — Very high (above target). This also shows up as a reddish color. If this continues, it is not good.

But keep in mind, some CGM reports may display this data differently. If you have trouble understanding this information, it's definitely a good idea to talk to your doctor . They can explain it to you.

How much should my TIR be?

If you have diabetes, the target range for your blood sugar levels is unique to you . That means your target range is not the same as mine. You and your doctor will decide together what target range is best for you and how much of that range you should aim to stay in. These goals may change throughout your life.

There are several factors that can affect glucose targets:

• How long have you had diabetes ?
• Your age and general health .
• You have other medical conditions that affect your blood sugar levels, such as kidney dysfunction or gastroparesis .
• If you have cardiovascular disease .
• A condition where you are unaware of the symptoms of low blood sugar (hypoglycemia unawareness)If there is. That is, if you don't feel the dizziness and sweating that you feel when your sugar level drops, it's a little risky.
• If you are pregnant or trying to get pregnant , your goals change a lot during these times.

Okay, now let's see what are the general recommendations that are usually given.

TIR targets for most adults with type 1 or type 2 diabetes:

• At least 70% of the time between 70 and 180 mg/dL (within the prescribed range).
• The time it is below 54 mg/dL should be less than 1%.
• The time between 54 and 69 mg/dL should be less than 4%.
• The time between 181 and 250 mg/dL should be less than 25%.
• The time it is above 250 mg/dL should be less than 5%.

TIR targets for people at higher than average risk of low blood sugar (hypoglycemia):

This is for those who often have low blood sugar.

• At least 50% of the time between 70 and 180 mg/dL (within the normal range).
• The time spent below 70 mg/dL should be less than 1%.
• The time it is above 250 mg/dL should be less than 10%.

TIR targets for adults with type 1 diabetes during pregnancy:

This is very important, because it can affect the baby.

• At least 70% of the time, it's between 63 and 140 mg/dL (in the normal range). The range here is a little different, see? It's very important to control your sugar levels during pregnancy.
• The time it is below 63 mg/dL should be less than 4%.
• The time it is above 140 mg/dL should be less than 25%.

The guidelines for gestational diabetes and type 2 diabetes during pregnancy may be different. Again, these are general guidelines. It is important to discuss with your doctor what glucose targets are most helpful and realistic for you. They will advise you on the best course of action for your situation.

What is the relationship between this TIR and A1C?

You've probably heard of this A1C test . Many doctors use it to see how well your diabetes is being controlled. So, are TIR and A1C the same thing? Yes, a little bit.

TIR measures the range of your glucose levels over a period of time, from a few hours to a few days, while you're wearing a CGM. It's like a short-term snapshot . You can see exactly how your sugar changes from day to day.

However, A1C is a blood test done in a lab . It measures your average glucose levels over the past 8 to 12 weeks . An A1C test cannot tell you how your blood sugar fluctuates. It only gives an average value.

Simply put:

Think of it this way: A1C is like reading a chapter summary of a book.. But using a `CGM` and looking at the TIR is like reading the whole chapter . Then you get a much deeper, more nuanced understanding of it. Do you understand? The TIR clearly shows how sugar behaves at different times of the day, after meals, after exercise.

Since the 1960s, doctors and diabetics have relied primarily on A1C to gauge how well diabetes management is going. However, since the advent of CGM machines, doctors and patients have realized that this TIR provides a more useful and accurate picture of diabetes management .

Especially for people with Type 1 Diabetes , blood sugar levels can fluctuate significantly over days, weeks, and months. Therefore, the average A1C value is not always an accurate measure of their management.

For example, consider:

There's someone whose blood sugar levels are constantly going very low and very high again. But their A1C might be 7%.

There's another person whose blood sugar level is stable at around 154 mg/dL most of the time. His A1C might also be 7%.

See? Even though their A1C is the same, their TIR values ​​can be very different. The first person's TIR is lower because he's constantly outside the target range. He's at higher risk for hypoglycemia.

Also, the A1C test may not be accurate in people with the following conditions:

• Anemia (blood deficiency).
• Hemoglobin variants.
• Iron deficiency.
• Pregnancy.
• Liver disease.

The accuracy of A1C values ​​can also vary among different populations.

However, as things stand, the advent of TIR does not mean that A1C testing will be obsolete . Decades of research have shown that A1C levels can predict the development or prevention of diabetes complications. Therefore, doctors are combining both TIR and A1C tests to get a more complete picture of glucose management.

Why is this TIR so important?

TIR gives you a more accurate picture of the fluctuations in glucose levels that come with diabetes. Think about how many things affect your sugar levels, such as the food you eat, the exercise you do, the medications you take, and your stress level ! So, looking at your TIR data (especially when using a `CGM`) can give you a better understanding of how these various factors directly affect your glucose levels .

For example, you may notice that your TIR has decreased when you have a fever for a week. Or, you may notice that your blood sugar has increased significantly after eating a particular food, and your TIR has decreased. When you see something like that, you can ask your doctor, 'How can I better prepare to control my diabetes the next time I get sick?' Or, you may think, 'How does that type of food affect me, and should I change the way I eat it?' In other words, TIR can be a great help in managing your diabetes in a way that suits your lifestyle .

Can diabetic complications occur if TIR decreases?

Research on this is still ongoing, but current studies have found that as TIR levels decrease, the risk of diabetes-related complications increases .

Studies show that large fluctuations in blood sugar levels (called glycemic variability) can increase oxidative stress and inflammation in the body. These conditions can damage cells . Some studies have linked these large glucose fluctuations to:

• Increased risk of low blood sugar (hypoglycemia).
• Increased risk of cardiovascular disease.
• Impairment of cognitive function.
• Decreased quality of life.

Furthermore, one study found that people with type 2 diabetes who had low TIR and high glycemic variability had a higher risk of diabetes-related retinopathy, a complication of diabetes that affects the eyes . Another study found that low TIR was significantly associated with a higher risk of cardiovascular autonomic neuropathy, a nerve disorder affecting the cardiovascular system .

So, these studies show the importance of keeping your TIR as high as possible . As researchers learn more, diabetes experts may change these TIR targets in the future.

How do I increase my TIR?

The key to improving your TIR is to figure out exactly what is affecting your glucose levels . This can take some time. In fact, it can feel like a never-ending science experiment. So, it's important to focus on one factor at a time and be kind to yourself . Don't panic, and try to figure these things out gradually.

If you notice that your glucose levels continue to rise or fall at certain times of the day, take a closer look at your habits and activities around that time.

For example, you may notice that your glucose levels continue to spike after breakfast. There are several reasons why this may be happening:

• It's not the right time to take your diabetes medication (e.g. insulin ).
• Insufficient or excessive dosage of medication.
• The balance of the foods you eat and the main nutrients they contain (carbohydrates, fat, and protein) . You may be eating too many carbohydrates.
• Other medications to take in the morning (some medications can affect blood sugar levels).
• Drinking caffeine- containing beverages like coffee in the morning (this affects some people).

This is just one example. Diabetes is a very complex condition . There are a number of strategies that can help you improve your TIR. As always, when you are considering making changes to your management plan, it is best to work with a diabetes specialist (e.g., an endocrinologist) or a certified diabetes care and education specialist (CDCES) . They can guide you through the process and answer your questions.

Take-Home Message

So, this “Time in Range” (TIR) ​​is a new and very useful way for people with diabetes to measure their glucose management. Understanding the TIR information and your glucose data can sometimes feel a little difficult. Don’t worry, you can get used to it little by little.

Remember, your doctor is always there to help you understand your TIR and use it to your advantage. Together, you can track how your TIR changes over time and adjust your management strategies accordingly. Living with diabetes is a challenge, but with new tools like these, it can be made a little easier. You are not alone, and there are many people who can help you on this journey.

`Diabetes, Time in Range, TIR, Glucose, Blood Sugar Level, CGM, A1C