A group of adults with type 1 diabetes that have not needed insulin for an average of 10 years and are maintaining near normal blood glucose thanks to islet cell transplantation, a new study shows. Islet transplantation is where isolated islets - groups of insulin-producing beta cells from the pancreas - from a donor are transplanted. Researchers from University of Miami's Diabetes Research Institute used continuous glucose monitoring to track the performance of the transplants in five people with type 1 diabetes. The results showed trends in glucose level control, which were near normal, as well as close to perfect time-in-range metrics. The participants were given islet transplants into the liver (intrahepatic islet transplant) from 2002 and 2010 and were then insulin independent for between seven and more than 16 years. Researchers carried out a seven-day assessment with the participants wearing continuous glucose monitors to assess glucose levels during the follow up. The glucose level data was compared to that of adults with type 1 diabetes who had not had the transplants but were using the latest diabetes technology (a hybrid closed-loop system) to help control their diabetes as well as possible. The results of the comparison showed that each one of the participants that had a transplant demonstrated an improvement in time-in-range glucose levels as well as less variability in glucose levels and lower exposure to low glucose levels (hypoglycemia). The participants were chosen as those who had achieved excellent success following transplantation. While these participants have achieved exceptional results, staying free from insulin injections for many years is not a guaranteed result of islet cell transplants. Many people undergoing the transplant need to start taking some exogenous insulin (insulin that is not produced by the body itself) again after months or years, depending on personal circumstances. One of the lead researchers on the study, Dr David Baidal said: "Using continuous glucose monitoring, we now have the ability to accurately evaluate patients' glucose profiles and their variability. The CGM data we have obtained from our islet transplant patients clearly demonstrates that islet transplantation can result in glucose levels that are close to those in people who do not have type 1 diabetes, even 10 years or more after undergoing the cell-replacement procedure." Dr Camillo Ricordi, who is a Joy Goodman Professor of Surgery as well as the director of the Diabetes Research Institute, has been named as the world's top islet transplantation researcher. Commenting on the study, he said: "This report confirms the superiority of transplantation of insulin-producing cells compared to insulin therapy, with glucose control results that were even better than the goals of CGM in hybrid closed-loop systems. "Hopefully, this will be of assistance in bringing islet transplantation closer to FDA approval, allowing the treatment to be made available to US patients, as has already been the case in several other countries, for many years." The results of the study were shared at the American Diabetes Association's 79th Scientific Sessions, which took place in San Francisco between June 7 and 11. They will also be presented at the 17th World Congress of the International Pancreas and Islet Transplant Association, which will take place in France between July 2 and 5.