Diabetes Knowledge

Lowering or raising the basal rate

Many pump users only use a temporary basal rate (which will reduce the basal delivery by a percentage over a period of time) when exercising and rarely, if at all, use the option to increase the basal rate.

However, there are so many situations each day, when insulin rates are higher or lower - regardless of food: taking the dog for a walk, stress at the office, quick shopping trips during the lunch hour, an hour's gardening, taking cortisone, two glasses of wine in the evening.

As soon as the blood sugar goes up or down, many pump users eat a few carbohydrates or give a bolus to compensate for the fluctuations.

Lowering instead of eating

Food, just to prevent hypoglycaemia during physical activities? This is counterproductive! In most cases, additional carbohydrate units can be avoided with a timely lowering of the basal rate. Not only when exercising, but also with many other daily activities associated with movement or increased physical activity.

Make the most of lowering or raising the basal rate

Lower the basal rate for e.g.: Raise the basal rate for e.g.:
Sport (for children also before PE) Colds
Housework Any illness accompanied by fever
Shopping Short-term bed rest (with longer duration a new basal rate profile is recommended)
Gardening Medication, e.g. containing cortisone
Tidying up the basement Stress/excitement
Moving house Shift work (sleeping during the day after a nightshift)
Shift work (nightshift) Women before or during menstruation
Whilst during surgery  
Women before or during menstruation (insulin demand may be higher or lower during this time, depending on individual circumstances)  
Alcohol consumption  

Gradual adjustment

How much do I increase or lower the basal rate and for how long? Blanket recommendations are not possible as individual insulin requirements vary.

Try lowering the basal rate in everyday situations

  • Lower the basal rate by 10% initially.
  • Please note: the reduction does not have an immediate effect, but requires a lead-time of 1.5 - 2 hours: with analogues insulin half an hour, with normal insulin an hour.
  • Measure your blood sugar prior to each activity (when exercising, the initial blood sugar should be at least 8.3 mmol/L).
    Is the value similar to the initial blood sugar level? ⇒ a drop of 10% is acceptable.
    Has the value gone down? ⇒ a lowering of 10% was insufficient, next time try 20%.
    Has the value gone up? ⇒ a lowering of 10% was too much, no lowering next time.
  • Please note that lowering the basal rate has a long-acting effect: an hour with analogue insulins or two hours with standard insulins.
  • The time to maintain the lower basal rate depends on, among other things, the type of activity and your general fitness. Walking your dog, for example, may only require a short-term lowering, while exercising requires lowering the basal rate over a longer period of time, since the body starts replenishing all the glucose storage (replenishing muscle glycogen stores) that is lost during exercise.
    When lowering or raising your basal rates, check your blood sugar until you know whether the percent value selected is suitable for certain situations.
    Ask your diabetes team for advice with regard to lowering or raising your basal rates.