Controlling Type 1 Diabetes

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A drug used to lower blood sugar may reduce the need for insulin pump users to count carbs.
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Many people with type 1 diabetes use insulin pumps to control their blood sugar. Carbohydrates increase blood sugar, so pump users need to carefully count the amount of carbohydrates that they consume in order to match their insulin doses to them.

Researchers at the Toronto General Hospital Research Institute have shown that the diabetes medication empagliflozin can eliminate the need for insulin pump users to track their carbohydrate intake.

People with type 1 diabetes do not produce insulin, a hormone required to control the amount of sugar in the blood. In addition to diet and exercise, many people with type 1 diabetes require lifelong insulin therapy to control their blood sugar levels.

Modern insulin pumps can monitor blood sugar levels and automatically adjust insulin delivery based on their users’ changing needs. These pumps, called “hybrid closed loop” systems, automatically deliver small amounts of insulin throughout the day, but depend on the user to determine how much insulin to give at mealtimes. The amount of mealtime insulin that a person needs depends on the amount of carbohydrates that they consume, so it is important for insulin pump users to keep track of the carbohydrate content of their meals. Unfortunately, this process is very difficult and time-consuming.

“An easier approach to administering mealtime insulin would be to simply signal that you are about to eat a meal by pressing a button on your pump, without having to carefully count the carbohydrate content of a meal. This approach is called ‘meal announcement’,” explains Dr. Bruce Perkins, a Senior Scientist at TGHRI and the senior author of the study. “Meal announcement is simple, but the insulin doses are less precise than when you count the grams of carbohydrate in your meal.”

To address these complexities, Dr. Perkins led a study to see whether the diabetes drug empagliflozin could reduce or eliminate the need to count carbohydrates. The study enrolled thirty adults who use insulin pumps. Over two months, each participant engaged in several insulin delivery strategies, including meal announcement and carbohydrate counting, with and without empagliflozin.

When participants combined the simple meal announcement and empagliflozin, their blood sugar was as well controlled as when they counted carbohydrates. When participants counted carbohydrates, the addition of empagliflozin further improved blood sugar control, substantially increasing the time spent in the target blood sugar range.

“If insulin pump users take empagliflozin, they can replace carbohydrate counting with a simple meal announcement strategy. The empagliflozin seems to make the automated insulin system work better at mealtimes. This switch can save people time and effort, without compromising blood sugar levels,” says Dr. Perkins. “Managing blood sugar levels in type 1 diabetes can be very challenging, but the strategy that we have identified has the potential to make it a little easier.”

Dr. Perkins’ team is currently studying the impact of empagliflozin in a much longer study.

This work was supported by Diabetes Canada, the Lunenfeld Tanenbaum Research Institute at Sinai Health Systems, McGill University and the UHN Foundation. A Haidar holds a Tier 2 Canada Research Chair in Diabetes Mellitus.

Haidar A, Yale JF, Lovblom LE, Cardinez N, Orszag A, Falappa CM, Gouchie-Provencher N, Tsoukas MA, El Fathi A, Rene J, Eldelekli D, Lanctôt SO, Scarr D, Perkins BA. Reducing the need for carbohydrate counting in type 1 diabetes using closed-loop automated insulin delivery (artificial pancreas) and empagliflozin: A randomized, controlled, non-inferiority, crossover pilot trial. Diabetes Obes Metab. 2021 Feb 2. doi: 10.1111/dom.14335.

The senior author of the study, Dr. Bruce Perkins, is a Staff Endocrinologist at Mount Sinai Hospital and University Health Network, and a Senior Scientist at the Toronto General Hospital Research Institute.