Diabetes Knowledge

Using bolus types

Evidence from studies in recent years shows that high postprandial blood sugar, i.e. post-meal spikes, is considered a risk factor for increased HbA1c values and resulting illnesses. These blood glucose spikes can be prevented by using an insulin pump, as this helps tailor the bolus insulin delivery specifically to the individual's food intake. Many modern insulin pumps offer a range of individual bolus types, which are worth trying out.

Option 1

The entire bolus is released at once

This option is called standard bolus or scroll bolus (with Accu-Chek insulin pumps), normal /express bolus (with the Paradigm insulin pump) or standard bolus or visual /Xpress bolus (with Deltec Cozmo).

Bolus 1 is the usual bolus with a normal meal composed of carbohydrates, fat and, protein, e.g. meat with potatoes and vegetables. The bolus is tailored to the carbohydrate units of the meal and the initial blood sugar level and released all at once. If the bolus is correct, the insulin lowers the blood sugar level within its duration of action, while preventing spikes.

Fat delays absorption

This calculation does not work for meals with high fat content, since fat delays the absorption of carbohydrates into the blood stream. A classic case would be pizza, or other 'problematic' dishes such as lasagne, gyros with French fries, tiramisu – but also meals that contain pulses (e.g. pea or lentil stew). If the complete bolus is released all at once – as with bolus 1 – blood sugar levels and insulin action are at odds with each other. At first, this will lead to hypoglycaemia, because the insulin is already at work, even though the carbohydrates have not arrived in the blood stream yet. Then, after around four to five hours, there will be a sharp rise in blood sugar, because now the carbohydrates start acting – but not the insulin.

Here, an insulin pump can help by offering two further bolus types:

Option 2

The bolus is delivered in small quantities over an extended, chosen period of time

Depending on the insulin pump, this type is called delayed or extended bolus or sometimes also referred to as the "pizza" bolus.

Option 3

A combination of standard and delayed bolus

This type is called multiwave or dual bolus, depending on the insulin pump.

The type of bolus delivery depends on the initial blood sugar level:

If the blood sugar before the meal is within the normal range, select the delayed or extended bolus. Calling up the bolus menu, first enter the entire bolus insulin amount and then the period, over which the bolus is to be delivered. The insulin pump will now deliver the bolus in equal amounts and at regular intervals over the chosen period.

You can also use the multiwave or dual bolus, if your blood sugar level before a meal is too high and requires adjustment. In this case, the insulin pump first delivers the pre-defined corrective dose that lowers the blood sugar to the normal range. This is followed by the delayed bolus, which - as with bolus 2 - can be selected as required.

Naturally, an initial standard bolus (bolus 1) to correct the blood sugar level can also be followed by a delayed and/or extended bolus (bolus 2). De facto, these are the two most frequently used bolus types - often when eating a meal over a longer duration such as at a buffet or a long dinner. This takes the worry off your mind of constantly having to think about the bolus if the meal is taking longer than anticipated. You will have to estimate the carbohydrate units, as you do not know how much you will be eating during the evening. It is recommended to go for a lower bolus initially, adding a single bolus later on.

* When selecting your bolus type, please refer to the instructions of your insulin pump.