From the Guidelines
The target time in range percentage for a patient with Type 1 Diabetes (T1D) should be at least 70% of readings within the target range of 70-180 mg/dL (3.9-10.0 mmol/L) 1. This means that ideally, a person with Type 1 diabetes should aim to have their glucose readings within this target range for at least 16.8 hours per day. Some key points to consider when aiming for this target include:
- Spending less than 4% of time below 70 mg/dL (hypoglycemia)
- Spending less than 25% of time above 180 mg/dL (hyperglycemia) These targets are important because maintaining glucose levels within range reduces the risk of both short-term complications like hypoglycemia and long-term complications such as retinopathy, nephropathy, and neuropathy 1. Time in range is considered a more comprehensive metric than HbA1c alone because it captures daily fluctuations and provides insight into glucose stability throughout the day. To achieve these targets, people with Type 1 diabetes typically need to use continuous glucose monitoring (CGM), carefully count carbohydrates, properly time insulin doses, and make regular adjustments to their insulin regimen based on patterns observed in their glucose data. It's also worth noting that each incremental 5% increase in time in range is associated with clinically significant benefits for individuals with type 1 diabetes 1. For younger individuals with Type 1 diabetes (under 25 years), the target time in range may be slightly lower, around 60%, if the A1C goal is 7.5% 1.
From the Research
Time in Target Range Percentage in Type 1 Diabetes
- The target range for Time in Range (TIR) in patients with Type 1 Diabetes (T1D) is generally considered to be above 70% 2, 3, with a glucose range of 70-180 mg/dL.
- However, some studies suggest that a more realistic target for TIR in pediatric patients with T1D may be above 50% 4, especially for those not using an automated insulin delivery system.
- The International Consensus on Time in Range recommends a TIR of >70%, a time below range (TBR) <70 mg/dL of <4%, and a TBR <54 mg/dL of <1% for the majority of people with type 1 or type 2 diabetes 3.
- Some studies have shown that certain insulin treatments, such as ultra-rapid lispro, can improve postprandial glucose control and increase time in range in patients with T1D 5.
- The American Diabetes Association and other organizations have not specified a specific time in range target for adults with T1D, but the general goal is to spend as much time as possible in the target glucose range while minimizing hypoglycemia and hyperglycemia 2, 6.
Factors Affecting Time in Range
- Glycemic variability and irregular lifestyles can make it difficult for patients with T1D to achieve the recommended TIR goals 2.
- The use of automated insulin delivery systems and other advanced technologies can help improve TIR in patients with T1D 2, 4.
- Individualized treatment plans and regular monitoring of glucose levels can also help patients with T1D achieve their TIR goals 3, 5.