Single-hormone compared to dual-hormone artificial pancreas during continuous and interval exercise

The authors aimed to determine whether the dual-hormone artificial pancreas reduces hypoglycemia (dangerously low blood glucose) when compared to insulin alone during exercise.

The authors concluded that the dual-hormone artificial pancreas out-performed insulin alone when controlling glucose levels during exercise in adults with type 1 diabetes.

The artificial pancreas is a new technology that helps people with type 1 diabetes automatically control their blood sugar levels by imitating the function of a healthy pancreas. The pancreas is responsible for maintaining the body's blood sugar balance by producing and releasing hormones, such as insulin and glucagon. Insulin is released to break down glucose taken in from food, while glucagon is released when blood glucose levels dip too low. In patients with diabetes, the pancreas does not produce the hormones as needed.

The artificial pancreas monitors blood sugar readings that are continuously transmitted to a monitor. This device can then control the delivery of hormones. The device can deliver one hormone (insulin) or two hormones (insulin and glucagon). The combination of the two can help to reduce the risk of hypoglycemia. However, how the two types of artificial pancreas perform during periods of exercise, when blood glucose levels can change rapidly, is still being examined.

The aim of this study was to determine whether the dual-hormone artificial pancreas reduced episodes of hypoglycemia compared to a single-hormone (insulin alone) artificial pancreas during continuous and interval exercise. 

17 patients were used in this study. All patients had had type 1 diabetes for more than 23 years. Patients were randomly assigned to receive single-hormone or dual-hormone treatment. Continuous exercise consisted of 60 minutes of moderate-intensity exercise. Interval exercise consisited of 2 minute alterations of high and moderate intensity exercise.  

During continuous exercise, 52.9% of patients experienced low blood sugar levels with single-hormone treatment. This was compared to 17.6% with dual-hormone treatment. During interval exercise, 46.7% of patients experienced low blood sugar levels with the single-hormone treatment. This was compared to 6.25% in dual-hormone treatment.

The average time spent with blood sugar levels below 4.0 mmol/l was significantly higher in the single-hormone group (22.5%) compared to the dual-hormone group (0%) during continuous exercise. Higher doses of glucagon were needed during continuous exercise (0.126 mg). This was compared to patients during interval exercise (00.93 mg). There were no reported side-effects experienced by patients. 

The authors concluded that the dual-hormone artificial pancreas outperformed insulin alone when controlling glucose levels during exercise in adults with type 1 diabetes.