News & Research
Adjusting Insulin Based on Monitoring Is Key
What is the problem and what is known about it so far?
Adjusting mealtime insulin doses based on carbohydrates consumed during meals is a good strategy for those who have type 1 diabetes, but it can be difficult for some patients and has not been rigorously tested in people who have type 2 diabetes.
Why did researchers do this particular study?
The researchers wanted to compare a strategy of adjusting insulin doses during mealtimes based on carbohydrate counting to one of taking a set amount of insulin per meal to see which was better for people with type 2 diabetes who were using a regimen including basal (background or steady insulin doses) and prandial (mealtime doses) insulin.
Who was studied?
The study included 273 adult patients with type 2 diabetes who were taking two or more insulin injections per day.
How was the study done?
In this 24-week study, participants had their insulin regimens adjusted weekly based on the previous week's premeal and bedtime blood glucose results. Then, one group was given a set dose of insulin to take before each meal for the coming week, whereas the other group was instructed on how to adjust mealtime insulin doses based on the amount of carbohydrates to be consumed at each meal.
What did the researchers find?
The two methods of setting mealtime insulin doses were equally effective. Both approaches led to average A1C (a measure of long-term blood glucose control) reductions of about 1.5 percentage points by the end of the study; there was no difference in the number of patients in each group who were able to reach their A1C targets. Patients reacted to both regimens well, and the risk for hypoglycemia (when blood glucose levels drop to dangerously low levels) was low and similar in both groups. Total daily insulin needs were large in both groups; however, for those who counted carbohydrates, insulin needs and weight gain were lower.
What were the limitations of the study?
It is possible that patients in the set-dose group may have consumed a fairly consistent amount of carbohydrate with each meal or adjusted their carbohydrate intake based on their blood glucose monitoring results. Either situation could have made achieving blood glucose control with a set amount of mealtime insulin easier to accomplish than it would have been if carbohydrate intake varied more widely from meal to meal and day to day.
What are the implications of the study?
Blood glucose targets can be achieved by adjusting insulin regimens based on premeal and bedtime monitoring results. Having two effective strategies for setting mealtime insulin doses (either by set doses or by adjusting based on carbohydrates) may increase patients' and doctors' willingness to try intensive insulin therapy and their success in using it.
FOR MORE INFORMATION
Carbohydrate counting: the basics
