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Lights! Camera! Insulin Action!

How Insulin Action Impacts Blood Glucose in an INSULIN PUMP program

Background Reading for this Article...
Before making any changes to insulin doses, it is important to understand the action of insulin (the onset, peak and duration of different types of insulin). Therefore, as background for the information that follows, we recommend you first review Insulin Types and Action.

Insulin is one of several factors that contributes to a given blood glucose reading at a certain moment in time. How insulin impacts blood glucose depends on the insulin action pattern of one of the three commonly used insulin programs:

  1. Conventional Insulin program 
  2. Basal/Bolus Program with Multiple Daily Injections
  3. Insulin Pump Program

Remember, in the following text:

“rapid-acting” insulin refers to Humalog®, NovoRapid®, or Apidra®


Insulin Pump Program

[Continuous Subcutaneous Insulin Infusion (CSII) of Rapid-Acting Insulin only]

The insulin action diagram for a Pump program (above) shows that the blood glucose at a given time is affected by a certain previous insulin dose (follow the curve back) as follows:

Blood glucose before breakfast tells you about Overnight basal rates
Blood glucose before lunch tells you about Morning basal rates + breakfast bolus
Blood glucose before supper tells you about Afternoon basal rates + lunch bolus
Blood glucose at bedtime tells you about Evening basal rates + supper bolus

For example, if the breakfast blood glucose is consistently out-of-range (high or low), you may want to change the overnight basal rates; if the supper blood glucose is consistently out-of-range (high or low) you may want to change the dose of lunch rapid-acting insulin and/or the afternoon basal rates.


The above information was adapted with permission from The Alberta Children’s Hospital Diabetes Clinic information handouts.

The above information was reviewed for content accuracy by clinical staff of the Alberta Children’s Hospital Diabetes Clinic.

This material has been developed from sources that we believe are accurate, however, as the field of medicine (in particular as it applies to diabetes) is rapidly evolving, the information should not be relied upon, as it is designed for informational purposes only. It should not be used in place of medical advice, instruction and/or treatment. If you have specific questions, please consult your doctor or appropriate health care professional.

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