Phone App Guides Healthy Rotation of Insulin Pumps, Sensors

pilot study tests how type 1 diabetes patients can use app to avoid skin complications

PHOENIX, Ariz. — January 18, 2023 — A new phone app developed by researchers at the Translational Genomics Research Institute (TGen), part of City of Hope, and the Mayo Clinic can help people with type 1 diabetes safely rotate the placement of their insulin pumps and glucose monitors.

The app, tested in ten people with type 1 diabetes who use continuous subcutaneous insulin infusion pumps, led to 84% compliance with site rotation recommendations, the researchers reported in the Journal of Diabetes Science and Technology.

Rotating the sites on the skin where pumps and monitors are placed helps patients avoid a complication called lipid hypertrophy, an abnormal accumulation of fat deposits under the skin. Along with skin irritation, this condition can interfere with insulin absorption, leading to poor glucose management.

“Despite the importance of site rotation, most studies show that patients with type 1 diabetes consistently rotate sites less than 60% of the time,” said Sampath Rangasamy, Ph.D., TGen Research Associate Professor in Neurogenomics and co-senior author on the paper. “Many patients do not know about the consequences of not switching sites, but around 40% of people develop lipohypertrophy, which impacts insulin absorption and increases insulin need.”

To help patients keep better track of their infusion and monitoring sites, Rangasamy and colleagues developed Insulin Site Guide, an app for the iPhone and iPad. Patients record the placement of injections, infusions and monitoring on the app. When the patient is ready to place the device, the app shows which sites on their body are available for placement and which should be “resting” before returning to the rotation of available sites.

The app offers a color-coded diagram of the body, showing “available” placement sites as blue and “unavailable or in use” sites as pink or red. When an unavailable site has rested long enough, it returns to blue to show its renewed availability.

Bithika M. Thompson, M.D., an endocrinologist at Mayo Clinic and co-senior author on the paper said, “Color coding was one of the ways the research team tried to make the app more user-friendly, especially as some older patients with type 1 diabetes experience vision problems.”

The patients in the study used the app for five weeks, and completed a survey about using the app. Ten patients using an insulin pump and glucose monitor tested the app and provided compliance data.

The researchers are seeking funding for a larger clinical trial of the Insulin Site Guide app, to test its potential impact on site rotation.

Type 1 diabetes affects 1.84 million people in the United States. Continuous insulin infusion pumps have become increasingly popular among type 1 diabetes patients, as the devices become smaller and less expensive.

Data gleaned from the app could also help researchers better understand how different sites in different patients absorb insulin, said Thompson.

“We want to map all the insulin infusion sites on a patient, see how they rotate between sites, and how that is connected to glucose control,” said John Blanchard, a TGen staff scientist and the paper’s first author.

These data could be useful in building better artificial pancreas algorithm, which Rangasamy called the next step in treating type 1 diabetes. The researchers also are examining molecular biomarkers in patients with type 1 diabetes that will help understand injuries at the site of insulin injection or infusion.

Research funding for the study comes from the Flinn Foundation (#2258).