Requirement for basal insulin
For most adults who eat regular food, the percentage of basal insulin of the total daily quantity of insulin is slightly less than half (40% to 50%) or roughly 0.2–0.5 units/kg. In practice, in the outpatient care, for example of slowly developing insulin deficiency, the insulin therapy can be started with an initial basal insulin dose of 8–12 units per day. After this, the dose is increased once or twice per week by approximately 10% at a time based on glucose sensor or blood glucose self-measurements.
Stable blood sugar during night as the goal
The basal insulin dose is the smallest number of units which achieves stable blood sugar at night. In this case, the evening-morning paired blood sugar test change is no more than ± 3 mmol/l, and the blood sugar does not rise or drop too much during the day if the interval between meals is prolonged. The suitable of the bsasl insulin dose can also be seen from the blood sugar level after waking up in the morning, before meals and at bedtime: as a rule, it should be 4–7 mmol/l.
If the amount of basal insulin is too high, it can easily lead to repeatedly low blood sugar, snacking or weight gain.
If the basal insulin is changed
Different basal insulin products may differ in terms of how much one dose lowers the blood sugar. If the insulin product is changed, adjustment of the dose based on glucose sensor results or self-measurements is required. At the same time, it is important to analyse the therapy as a whole:
Are the current basal insulin dose and the time suitable?
Is the basal-insulin-to-mealtime-insulin ratio correct?
Is the insulin-to-carbohydrate ratio (IHS) correct at different times of the day?
Is the correction factor of rapid-acting insulin, sometimes called insulin sensitivity (IHT), suitable at different times of the day?