Mount Sinai Endocrinologists Expand Diabetes Technology Use

Mount Sinai endocrinologist Carol J. Levy, MD, and her team are working to expand the use of automated insulin delivery (AID) technology—studying its use in insulin-requiring people with type 2 diabetes and during pregnancies complicated by type 1 diabetes.

The technology, also known as “closed-loop” or “artificial pancreas” systems, comprises insulin pump and continuous glucose monitoring (CGM) devices with algorithms that partially automate insulin delivery based on glucose levels and trends. So far, use of AID systems has been primarily focused on use in people with type 1 diabetes.

“We’re moving down a path. We started with the people at the highest risk and in the greatest need of automated insulin delivery—people with type 1 diabetes whose bodies make no insulin. Now, we’re working our way into other populations that can derive benefit,” says Dr. Levy, Director of the Mount Sinai Diabetes Center and Associate Chief for Endocrine Clinical Research, Mount Sinai Health System.

One of the studies focuses on people with type 2 diabetes who require insulin. Because people with type 2 diabetes retain some endogenous insulin production, the majority have a broader range of therapies to manage their blood glucose levels. However, over time at least 20 percent of people with type 2 diabetes end up requiring insulin to achieve adequate blood sugar control. Given the prevalence of type 2 diabetes—about one in 10 Americans—the insulin-requiring type 2 diabetes population of about 7 million people actually exceeds the entire number of people with type 1 diabetes in the United States, roughly 1 to 2 million, notes Dr. Levy, Professor of Medicine (Endocrinology, Diabetes and Bone Disease) at the Icahn School of Medicine at Mount Sinai.

“People with type 2 diabetes generally develop it when they’re older, and these individuals are a very different population from those with type 1. But a lot of these people do require insulin, and we need to develop strategies to best manage their diabetes,” she says. “They deserve, as do people with type 1, to have options to reduce the burden of care. We’ve shown that these systems really do provide benefit in people with type 2 diabetes.”

The prospective, single-arm study for which Dr. Levy was the protocol chair was published in August 2023 in Clinical Diabetes. The system tested, a commercial product, comprises an insulin pump with an incorporated algorithm and a continuous glucose monitor (CGM), both worn on the body. The insulin pump is software trends from the CGM to direct automated insulin delivery. Individuals still with all of these systems need to enter dosing for food. The system was approved in early 2020 based on research performed by a consortium of expert investigators, including Dr. Levy’s team, from a pivotal trial sponsored by the National Institutes of Health

This initial study included 30 adults with type 2 diabetes who used the commercially available Tandem t:slim X2 insulin pump with Control-IQ technology advanced hybrid closed-loop AID system for two to four weeks, along with any other glucose-lowering medications they were taking. Their mean time-in-range of 70-180 mg/dL increased by 15 percent, or about 3.6 hours per day, with a mean glucose reduction of 22 mg/dL with no increase in hypoglycemia.

Dr. Levy is now an investigator for a multisite randomized controlled trial of about 180 people with type 2 diabetes, comparing the closed-loop system with standard of care. “It’s not for everyone with type 2 diabetes but rather those already requiring insulin with or without other medications for type 2 diabetes. But I think this could represent an option for those who are struggling to keep their glucose levels in range,” says Dr. Levy.

The second study focuses on the unique needs of pregnant people with type 1 diabetes. Currently, there is no AID system approved by the U.S. Food and Drug Administration (FDA) for use during pregnancy. Commercial systems are used off-label; the algorithms aren’t aggressive enough to target the very narrow glucose ranges required during pregnancy, Dr. Levy says.

The single-arm, observational prospective multicenter study, published in July 2023 in Diabetes Care, tested an investigational hybrid closed-loop system using a pregnancy-specific algorithm developed by Harvard engineers, running on an unlocked smartphone designed for home use.

Ten pregnant women with type 1 diabetes who were already using insulin pumps were enrolled in the trial during their second or early third trimester. The investigational system targeted a daytime glucose range of 80-110 mg/dL and 80-100 mg/dL overnight. The women were allowed unrestricted meals and activities.

The primary outcome, percentage of glucose time in the pregnancy-specific range of 63-140 mg/dL, increased by 14.1 percentage points, translating to 3.4 hours per day, compared with the run-in period at the start of the study (78.6 percent vs. 64.5 percent). While using the AID system, the women spent significantly less time with glucose levels above 140 mg/dL or with hypoglycemic levels below 63 mg/dL and 54 mg/dL. Nine of the 10 achieved the goal of more than 70 percent time in range while using the system.

This study was the first in the United States to allow women to go home using an investigational pregnancy-tailored pump. “To get the FDA to approve 10 women to go home during the pandemic with these tighter targets is huge,” Dr. Levy says.

Larger trials are needed and are now being planned with support from the Helmsley Charitable Trust, Dr. Levy says. “My goal is for there to be a commercial product in the United States for use during pregnancy.”