Version July 2025
COMMENT —
There is no consensus among practicing clinicians and experts about the proper schedule for the administration of insulin in patients with type 2 diabetes. In fact, the large number of regimens proposed by experts and in use is confusing and may be intimidating. The available studies that compare different regimens have focused on differences in metabolic outcomes (glycated hemoglobin [A1C]) and adverse events, especially hypoglycemia. The differences between regimens are modest, at most. When differences in glucose and A1C levels have been found, they have been small and sometimes offset by adverse events such as hypoglycemia or weight gain. None of the studies provide information regarding differential effects of various insulin regimens on microvascular or macrovascular complications or mortality. In view of these considerations, the following guidelines may be helpful.
●Familiarize yourself with a small number of regimens (to allow for patient preferences, lifestyle, etc), and use them consistently.
●Conquer insulinophobia! The correct dose of insulin is determined by the results achieved in terms of blood glucose and A1C levels, not by an arbitrary number of units a day (and certainly not by the number of units per day required for patients with type 1 diabetes). In the usual patient with type 2 diabetes, the dose is in the range of 0.6 to 1.0 units/kg per 24 hours.
●Once you initiate a regimen, advance doses incrementally until the target levels of blood glucose and A1C are achieved. Frequent changes in regimen delay the achievement of goals and may confuse, frustrate, and demoralize the patient.
●Keep it simple. In many patients with type 2 diabetes who need insulin for the first time, a single dose of insulin per day is usually sufficient. The issue is usually the use of a sufficient quantity of insulin, not the number of injections per day. Avoid the situation in which the patient is on multiple injections per day but the total dose of insulin is insufficient and the A1C remains elevated. Of course, in some patients, it may not be possible to achieve adequate glycemia management with a single injection per day, because glycemia is satisfactory only at certain times of day. This usually becomes evident in the process of advancing incrementally the dose of a single injection of insulin per day. In these patients, a more complex regimen may be necessary.
Initiation of insulin therapy with a basal insulin has the advantage of convenience and simplicity in patients who are using insulin for the first time. Use of a basal insulin as the initial regimen may produce less weight gain and hypoglycemia than use of a biphasic insulin mixture or prandial insulin doses only, as observed in the Treat-to-Target Trial. These possible advantages may relate to study design and are not sufficient to support a recommendation for basal insulin as the only approach to the initiation of insulin in all patients with type 2 diabetes. Patient preferences and lifestyle (eg, meal and activity patterns) may lead to the use of an alternative approach. It is often helpful to ask the patient: "Are you more likely to forget your insulin in the morning or in the evening?" Then, select the regimen that is most likely to enhance compliance. (See "Insulin therapy in type 2 diabetes mellitus".)
In the Treat-to-Target Trial, over the first three years of treatment with a basal insulin only or prandial insulin doses only, approximately three-quarters of the patients required the addition of the other type of insulin to achieve an A1C value of 6.5 percent or lower. Thus, insulin regimens tend to converge over time into a combination of basal insulin and a prandial insulin using a short- or very short-acting insulin. Nevertheless, it is usually worthwhile to start with a simple regimen for the reasons noted above.
[1-3]
