What is Time in Range and What Does it Mean for Diabetes Management?

Medically reviewed by Dr. Jordan Pinsker, Vice President & Medical Director, Tandem Diabetes Care.

In the world of diabetes management, a commonly used phrase is “Time in Range” or TIR. What is time in range and how does it apply to diabetes management? This article will discuss ways to achieve a better glucose range and examine what’s considered a solid target time in range.

What is Time in Range?

Time in range is a glucose management measure and gauge for the amount of time glucose levels are in what’s considered a “healthy” target range for people living with diabetes.

Anything outside of this range may be considered low blood sugar (hypoglycemia) or high blood sugar (hyperglycemia). Read more about the differences between hypoglycemia and hyperglycemia.

Understanding a healthy time in range is essential to diabetes management. People living with diabetes should talk with their healthcare provider about achieving a target time in range. 

When someone is outside of the targeted range, it is possible that they may experience symptoms of hyperglycemia or hypoglycemia. However, to understand time in range, it’s important to understand the basics of glucose.

What is Glucose?

Glucose is a type of sugar/carbohydrate that can enter cells and provide energy, or it can be stored by the body in the liver until it is needed. Glucose is a macronutrient — an essential element the body needs. The three major macronutrients are carbohydrates, fats, and proteins. Read more about understanding glucose and how to monitor it.

What is a “Healthy” Time in Range?

The idea of “healthy” or “normal” can vary from individual to individual and depends on a wide variety of factors. So rather than giving a specific number for what is considered “healthy,” a range was created. Type 1 diabetes is not one size fits all. Rather, endocrinologists want to see their patients aim for a “target” time in range.

A widely accepted range for glucose levels for a non-pregnant individual with type 1 diabetes is 70 to 180 mg/dL. This is considered to be a target range by most endocrinologists, diabetes educators, and other healthcare providers. This is also considered the standard healthy range by the American Diabetes Association guidelines.

Time in range goals should be similar for people living with type 2 diabetes or prediabetes.¹

What Impacts Time in Range?

There are many factors that impact someone’s glucose, which will ultimately impact time in range.  Rather than targeting a single number, a range was created because the body’s glucose levels can fluctuate throughout the day for a number of reasons.²

These could include:

• Increased activity, such as physical exercise
• Decreased activity
• Food intake
• Illness
• Stress levels
• Hormonal shifts
• The time of day
• Menstruation
• Alcohol
• Medications
• Dehydration

"Current guidelines recommend most people with type 1 and type 2 diabetes should aim for a time in range of at least 70 percent of readings — meaning you should aim for about 17 out of 24 hours each day to have a glucose level in range (not high or low),” said Dr. Jordan Pinsker, Vice President and Medical Director for Tandem Diabetes Care.

What is Insulin and How Does it Work?

Insulin is a hormone that the body produces in the pancreas. It allows the body to generate energy from glucose. The body is constantly using energy — whether that’s walking, typing, exercising, or thinking. Every action requires energy, and insulin helps the body metabolize glucose into energy.

Because these levels are continuously fluctuating, the pancreas is constantly producing insulin to account for the body’s changing needs. However, for someone living with diabetes, their pancreas either does not produce insulin or the body does not use the insulin efficiently.

Read more about insulin and how it works.

The use of an insulin pump is an effective way to help manage diabetes. Read more about insulin pumps.

When there isn’t enough insulin in the body, it can lead to high glucose levels, or hyperglycemia. Conversely, if there is too much insulin, it can lead to lower glucose levels, which is known as hypoglycemia.

What are the Signs and Symptoms of Hyperglycemia?

There are different levels of what is considered hyperglycemia. When someone living with type 1 diabetes has high glucose levels that exceed 180 mg/dL, is mild hyperglycemia. Severe hyperglycemia occurs above 250 mg/dL, and can be dangerous if not addressed with insulin and fluids.  People living with diabetes should discuss hyperglycemia with their doctor to understand when they should be concerned.

(Please note that the following symptoms may not be an indication of hyperglycemia for all individuals. Please consult a healthcare professional for further information.)   

Initial symptoms of hyperglycemia could include: 

• Headache 
• Fatigue 
• Impaired vision 
• Excessive thirst 
• Increased urination

More severe symptoms may include: 

• Difficulty breathing 
• Fruity-scented breath 
• Confusion 
• Weakness 
• Nausea/vomiting 
• Abdominal pain 

Note that if insulin is not present or working well enough for the body to absorb glucose, the body will try to burn fat. This can lead to the burning of ketones, which can trigger a very serious condition called diabetic ketoacidosis, or DKA. This is not to be confused with a keto diet. People living with diabetes who have ketones present in their urine should take immediate action. This is a medical emergency.

Read more about DKA here.

What are the Signs and Symptoms of Hypoglycemia?

Hypoglycemia is the result of glucose levels that go too low. If an individual’s blood sugars drop below 70 mg/dL, this is considered hypoglycemia. Like hyperglycemia, the symptoms can be extremely severe, or very mild depending on the individual and circumstances.

(Please note that the following symptoms may not be an indication of hypoglycemia for all individuals. Please consult a healthcare professional for further information.)   

Initial symptoms of hypoglycemia could include: 

• Shaking 
• Headache 
• Hunger 
• A light-headed or “woozy” feeling 
• Sweating  

More severe symptoms may include: 

• Confusion 
• Blurred vision 
• Seizures 
• Passing out

Severe cases of hyperglycemia and hypoglycemia are medical emergencies.

How to Reach a Target Time in Range

Achieving a target time in range is very important for diabetes management. A target of 70% of the time spent between 70-180 mg/dL is a great goal for someone living with type 1 diabetes. Starting on a continuous glucose monitoring (CGM) sensor can help someone living with diabetes get a real-time look at their glucose levels.

Dr. Pinsker, who is also a leading endocrinologist, says that getting on a CGM immediately after diagnosis of type 1 diabetes should be the standard of care.

Adding an insulin pump with an advanced hybrid closed-loop system can also help achieve more time in range. Learn more about pumps with advanced hybrid closed-loop systems.

The t:slim X2 insulin pump with Control-IQ technology from Tandem Diabetes Care has been shown to increase time in range* during the day and overnight. In fact, in a clinical study of participants using Control-IQ advanced hybrid closed-loop technology, participants spent up to 2.6 more hours in range per day.³

Unless otherwise noted, all medical information was provided by Jordan Pinsker, MD, and Molly McElwee Malloy, RN, CDCES of Tandem Diabetes Care, Inc.

*As measured by CGM.

References

¹ Battelino et al. Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range. Diabetes Care. 2019; 42(8):1593-1603.
² Good to Know: Factors Affecting Blood Glucose. Clin Diabetes. 2018;36(2):202. doi:10.2337/cd18-0012
³ Brown SA, Kovatchev BP, Raghinaru D, et al. Six-month randomized, multicenter trial of closed-loop control in type 1 diabetes. N Engl J Med. 2019;381(18):1701-1717. doi: 10.1056/NEJMoa1907863.

Responsible Use of Control-IQ Technology

Important Safety Information