Glucose Targets: How to Adjust your Insulin Doses

Your Diabetes Targets: 

• Pre meal Blood Glucose Levels (BGL): 4 mmol/L – 7 mmol/L
• Continuous Glucose Monitor (CGM) Time In Range (TIR) of at least 70-75%
• HbA1c less than 6.5% 
  

High blood glucose = Hyperglycaemia

BGL Above 7 mmol/L before meals +/- 10 mmol/L or higher 2-3 hours after eating 

Low blood glucose =Hypoglycaemia

BGL of 3.9 mmol/L or less

Look for patterns 

If you notice a high or low blood glucose pattern for 3 days in a row or 4 times in 1 week this means that your child's insulin doses or ratios need to be adjusted

Key tips to making the right dose adjustment: 

With diabetes, glucose levels outside of the target ranges will occur but the key is to recognise this and intervene as needed to reduce the frequency of this. Too high = not enough insulin for your child's requirements in recent hours. Too low = more insulin than needed for your child's requirements in recent hours. 

• Do not change your insulin based on a single higher or lower reading. 
  
• Make another change after 3 days if needed.
• If you are using CGM login to your account to look at your data on a computer or tablet at least once per week to view glucose patterns (LibreView®, Clarity®, Glooko®, CareLink®). These reports allow you to view your Time In Range and see the times of the day you are running. higher/lower and need to make a change. 
• Check glucose levels 2 hours after eating. If your glucose is between 3.9 – 10 mmol/L the insulin dose is appropriate

How to adjust insulin 

Hyperglycaemia (high glucose levels) happening: 

Before breakfast or overnight glucose readings above 7 mmol/L 

Increase your long acting insulin (i.e. glargine/Levemir®) by at least 10% 

Lunch time glucose pattern above 7 mmol/L or 2 hours after breakfast above 10 mmol/L 

Increase your breakfast dose of NovoRapid®/Humalog® by at least 10%

Dinner time glucose pattern above 7 mmol/L or 2 hours after lunch above 10 mmol/L 

Increase your lunch dose of NovoRapid®/Humalog® by at least10% 

After dinner or before bed pattern above 7 mmol/L or 2 hours after dinner above 10 mmol/L 

Increase your dinner dose of NovoRapid®/Humalog® by at least 10%

Increasing dose by 10% examples: 

• If giving 4 units, adjust to 4.5 units 
• If giving 10 units, adjust to 11 units 
• If giving 22 units, adjust to 24 units 
  

Hypoglycaemia (low glucose levels) - 3.9 mmol/L or lower happening: 

Before breakfast or during the night 

Reduce your long acting insulin (i.e. glargine/Levemir®) by 10% 

Before lunch or after breakfast  

Reduce your breakfast dose of NovoRapid®/Humalog® by 10%

Before dinner or after lunch 

Reduce your lunch dose of NovoRapid®/Humalog® by 10% 

After dinner or before bed 

Reduce your dinner dose of NovoRapid®/Humalog® by 10%

Decreasing dose by 10% examples: 

• If giving 4 units, adjust to 3.5 units 
• If giving 10 units, adjust to 9 units 
• If giving 22 units, adjust to 20 units 

Tips to keep in mind when considering making an increase to insulin doses:

• Check for previous hypoglycaemia and adjust long-acting insulin working overnight to manage low glucose levels first. 
• Sometimes glucose levels can go higher after treating a low glucose reading. If there is a pattern of glucose levels going above 7 mmol/L after treating hypoglycaemia, you should consider if you are over treating the low glucose e.g. by having too much quick acting/high glycaemic index carbohydrate, check hypoglycaemia quantities here.
• Consider the timing of your insulin to when you eat your food and wait 15 minutes after giving insulin to help avoid unnecessary glucose spikes after eating.
• Make a note in your CGM app or record book of different events on that may have contributed to high glucose levels, such as big family dinners where the dose of insulin was not increased, or sick days where no changes were made to the insulin dose.

Tips to keep in mind when considering making a decrease to insulin doses:

• For newly diagnosed patients, changes may be needed more frequently in the initial weeks after being diagnosed because of the “honeymoon” period starting. In the weeks after being diagnosed with type 1 diabetes, your body can temporarily make its own insulin again. If you start experiencing low BGLs, the doses of insulin will need to be reduced (remember insulin can never be stopped but can be reduced if you are having low glucose readings).
  
• Consider and make note of different days that may have contributed to the hypoglycaemia e.g. a sports day, unwell
• Always ensure you are doing confirmatory finger prick BGL if your CGM alerts for hypoglycaemia
(3.9 mmol/L or lower). 
  

Page updated September 2024