If you have type 2 diabetes, the HbA1c level in your blood will be measured 1 to 2 times a year. That is the average of your blood sugar over the past 2-3 months. Based on this value, your doctor, diabetes nurse or practice nurse can see whether a treatment is working or not. The higher your HbA1c, the higher your blood sugars have been in recent months. 

The best value for HbA1c in type 2 diabetes is less than or equal to 53 mmol/mol. Because it’s an average, it just doesn’t say much about your daily values and fluctuations. Imagine 3 persons Els, Owen and Daisy. They all have the same average HbA1c value of 53 mmol/mol. But if we look at the development of their HbA1c value, you see differences.

• Els has a strongly fluctuating sugar level (high peaks and dips)
• Owen has a stable sugar level
• Daisy has high values at the beginning (e.g. on vacation) and lower values at the end (e.g. at home)

If your value at the check-up is 53 mmol/mol or lower, then you will receive good news. While that holiday period with many high values has not necessarily been good for your health. Many strong fluctuations on a daily basis is also not good for you. But your HbA1c level just says nothing about this.

With a glucose sensor you do get insight into your daily fluctuations. The sensor immediately shows you how you react to food, exercise, stress, illness and other factors. You can see at a glance what your sugar level looks like in a day. To determine whether this is correct, you can look at the ‘Time in Range (TIR)”. This is the time that your glucose value is within the target range. The longer that is, the better. Your HbA1c will also be lower with a higher Time in Range.

The target range for people with diabetes is between 3.9 and 10 mmol/l. If your glucose value is higher than 10 mmol/l after a meal, you are outside your target range and your Time in Range will therefore be lower. If your glucose value remains between 3.9 and 10 mmol/l for at least 70% of the day (= about 17 hours), then that is good. If you do not achieve this, for example because you regularly peak after a meal, you could adjust this meal or take a walk after the meal to stay below 10 mmol / l. Your Time in Range will become higher and the risk of complications of, for example feet, eyes, kidneys, nerves and cardiovascular disease, lower.

Below you see a real day curve of someone with a Time in Range of 100% and of someone with a Time in Range of 68%.

The first person is already doing very well. It is also nice to see that exercise after breakfast prevents the sugar level from rising much and also lowers the value.

The second person could get started with improving his breakfast. Two peanut butter sandwiches led to an increase above 10 mmol/l. He could try a different breakfast to see if the sugar level rises less. For example, a breakfast with cottage cheese, red fruit and nuts / seeds / kernels. If the sugar level rises less as a result or even stays below 10 mmol/l, the Time in Range will be higher, which is ultimately better for his health.