Time in Range: Is It Better for Diabetes Care Than A1C Alone?

When it comes to diabetes care, understanding your blood sugar patterns is just as important as knowing your averages. For years, A1C has been the go-to measure of long-term glucose control, offering a picture of your average levels over two to three months. But as technology and research advance, time in range (TIR) is emerging as a more dynamic and actionable metric. Here, we'll discuss some important information about time in range and its benefits.

In this article, you’ll learn:

• What time in range (TIR) is, and how it measures the percentage of time your blood sugar stays within your target range (usually 70–180 mg/dL).
• How TIR provides a more detailed picture of daily blood sugar patterns than A1C alone.
• The meaning of Time Above Range (high blood sugar) and Time Below Range (low blood sugar).
• Why TIR is important for reducing complications, improving quality of life, and supporting personalized diabetes care.
• The limitations of A1C, which only reflects an average over 2–3 months, and can miss highs and lows.
• Key differences between A1C and TIR.
• Recommended TIR goals (at least 70% of the day in range) and how they can vary by age, health status, and pregnancy.
• Ways to improve TIR, including:
  • Using a Continuous Glucose Monitor (CGM)
  • Eating balanced meals
  • Staying active
  • Taking medications consistently
  • Managing stress and getting good sleep
  • Reviewing glucose patterns with your care team
• How CGMs and support from your healthcare provider can help you optimize your diabetes management.

What is Time in Range (TIR)?

Time in range (TIR) is a diabetes management metric that shows the percentage of time a person’s blood glucose levels stay within a recommended target range. For most people with type 1 diabetes or type 2 diabetes, this range is 70–180 mg/dL, though individual targets can vary depending on age, health conditions, or pregnancy. The percentage is translated as hours per day spent in the target range. For example, 50% time in range means 12 hours per day spent within 70 to 180 mg/dL.

Unlike A1C, which reflects an average blood sugar level over roughly three months, TIR gives a real-time picture of daily glucose control. It tells you not just the average, but how often your blood sugars are actually in your target range versus too high (hyperglycemia) or too low (hypoglycemia).

TIR is typically measured with a continuous glucose monitor (CGM), which tracks glucose levels 24 hours per day and provides detailed insights into fluctuations throughout the day and night. While you can use a manual finger prick to calculate TIR, it requires that you check your blood sugar several times a day and still won't provide the same type of glucose data as a CGM.

What is Time Above Range?

This measures the percentage of time your blood glucose is higher than your target range, typically above 180 mg/dL. A high time above range can indicate frequent hyperglycemia, which may increase the risk of long-term complications if not addressed.

What is Time Below Range?

This tracks the percentage of time your blood glucose is lower than your target range, usually below 70 mg/dL. A high time below means you’re experiencing more hypoglycemia, which can cause symptoms like shakiness, confusion, or dizziness, and can be dangerous if severe.

Why is Time in Range Important for Diabetes Care?

Time in range is a good measure of overall glycemic control, but it is just one component of overall care. Always work with a healthcare provider and your diabetes team to better understand your target blood glucose range and associated management techniques. Still, some of the most notable reasons that time in range can be great for managing diabetes include:

• It provides a clearer picture than A1C alone by showing real-time highs and lows instead of just a three-month average.
• It helps reduce the risk of diabetes complications such as nerve damage, kidney disease, vision problems, and cardiovascular issues.
• It improves daily quality of life by minimizing symptoms like fatigue, mood swings, and brain fog.
• It supports personalized care by allowing patients and providers to fine-tune diet, exercise, and medications based on patterns.
• It empowers patients through continuous glucose monitor (CGM) alerts and data that make self-management more confident and proactive.

Understanding A1C and Its Limitations

A1C is a blood test that measures the average blood glucose levels over the past two to three months. It works by looking at how much glucose is attached to hemoglobin, the protein in red blood cells that carries oxygen. It's also sometimes referred to as HbA1C (hemoglobin A1C); the two terms can be used interchangeably.

A1C results are reported as a percentage. For example:

• A normal A1C (without diabetes) is below 5.7%.
• Prediabetes is 5.7–6.4%.
• Diabetes is diagnosed at 6.5% or higher.

Glucose goals for many people with diabetes are an A1C below 7%, though this can vary based on age, health, and individual circumstances.

Unlike using TIR, A1C doesn't provide information on glycemic variability; it only provides your average glucose levels over the last few months. This means that someone could technically have good A1C levels, but still experience frequent highs and lows, which may not be ideal for living with diabetes over the years. It's also not personalized, as the average A1C may be the same for two different people with very different daily glucose experiences and risks. Still, it does remain an essential part of a more comprehensive diabetes management plan.

Key Differences Between Time in Range vs A1C

While both time in range and A1C measure aspects of blood sugar control, they provide very different insights into diabetes management. For example:

• A1C reflects your average blood glucose over about two to three months.
• TIR shows the percentage of time your glucose stays within your target range (typically 70–180 mg/dL).

The level of detail also varies, which can be helpful for risk assessment and more.

• A1C gives a single number, an average, without showing highs and lows.
• TIR offers real-time insight into daily fluctuations, helping identify when you’re spiking or dropping.

Does Time in Range Matter More for Daily Diabetes Management?

Overall, time in range is an essential tool for people with type 1 diabetes and people with type 2 diabetes who use insulin. It's also suitable for those who are at an increased risk of hypoglycemia, and can be an excellent tool for collaboration with your diabetes care team.

According to recent research, TIR is set to become the gold standard for glycemic assessment, as it may drive better clinical outcomes. Still, it's important for people with type 1 and type 2 diabetes mellitus (or anyone with any form of diabetes that's been cleared to use a CGM device) to incorporate time in range goals into a comprehensive diabetes management plan rather than using it as a standalone metric.

What is a Good Time in Range Goal?

Recommendations from the International Consensus Report on Time in Range (TIR) and The American Diabetes Association Standards of Care is that nonpregnant adults with type 1 or type 2 diabetes spend at least 70% of the day (17 hours of a 24-hour day) in the target glycemic range of 70 to 180 mg/dL, which corresponds to the recommended hemoglobin A1C (HbA1c) target of approximately 7%. Other TIR general guidelines for individuals with type 1 or type 2 diabetes include:

• Less than 1% of the time below 54 mg/dL
• Less than 4% of the time from 54 to 69 mg/dL
• Less than 25% of the time from 181 to 250 mg/dL
• Less than 1% of the time above 250 mg/dL

Regardless, everyone's target glucose range can vary and may even change throughout your lifetime. While the above numbers are the international consensus on time in range, the exact target can vary based on:

• The amount of time you've been living with diabetes
• Your age
• Certain underlying conditions that affect blood sugar (i.e., kidney dysfunction or gastroparesis)
• Whether you have cardiovascular disease
• If you have hypoglycemia unawareness or a higher risk of hypoglycemia
• If you're pregnant or trying to get pregnant

The best way to determine your time in range numbers is to ask your healthcare provider and work with your diabetes care team.

How to Improve Your Time-in-Range

Since there's a correlation between time in range and diabetes complications, it's worth looking at ways to improve your metrics. Some of the most practical ways to help you stay in range more consistently and reduce A1C levels include the following:

Use Continuous Glucose Monitor (CGMs)

A CGM provides real-time glucose readings and trend alerts, helping you catch highs or lows before they become severe. Reviewing your CGM reports with your healthcare provider can reveal patterns and guide adjustments.

Monitor and Adjust Your Diet

Choose balanced meals with fiber, protein, and healthy fats to prevent spikes, and be mindful of portion sizes and carbohydrate timing. Tracking how different foods affect your glucose can help you make smarter choices.

Stay Active

Regular physical activity improves insulin sensitivity and helps stabilize blood sugar. Aim for a mix of aerobic exercise (like walking or swimming) and strength training throughout the week.

Follow a Consistent Medication Routine

Take insulin or other prescribed medications as directed, and work with your provider to fine-tune dosing if you’re frequently going out of range.

Manage Stress and Sleep

Stress hormones and poor sleep can cause unexpected glucose fluctuations. Practice relaxation techniques, maintain a bedtime routine, and aim for seven to nine hours of quality sleep each night.

Review Patterns Regularly

Use CGM data or glucose logs to identify trends and review these with your diabetes care team regularly. These trends can include things such as glucose changes after meals, at different times of day, or activities that lead to spikes or drops. This type of insight can help you make small, targeted changes for long-term success.

By using high-quality diabetes products and working closely with your healthcare team, you can make informed decisions to improve daily management and long-term health outcomes. Byram Healthcare is here to help with diabetes supplies and access to the latest CGM technology. Contact Byram’s Diabetes Helpline: 1-877-902-9726, ext. 43397, to learn more today.