March 21 (UPI) -- Type 1 diabetics' potentially fatal low blood glucose levels improved dramatically with the transplantation of insulin-producing islets to their pancreas, according to findings from a Phase 3 clinical trial in the United States.
The National Institute of Allergy and Infectious Diseases and the National Institute of Diabetes and Digestive and Kidney Diseases funded the trial, which ran from October 2006 until May 2014.
The findings were published Tuesday in the journal Diabetes Care.
Pancreatic islets, also called islets of Langerhans, are tiny clusters of cells in the pancreas. In people with type 1 diabetes, the immune system attacks and destroys insulin-producing cells in islets. Diabetics must take take insulin from injections or pumps to live, but they cannot control blood glucose levels as precisely as insulin released naturally from the pancreas.
While just a small number of functional insulin-producing cells are necessary to restore hypoglycemic awareness, they might not be enough to fully regulate a person's blood glucose levels, researchers say.
The 48 participants at eight sites in the United States generally reported better overall health status after the transplant, although they need lifelong treatment with immune-suppressing drugs to prevent transplant rejection. All participants had hypoglycemia unawareness, which is an impaired ability to sense drops in blood glucose level, and had frequent episodes of severe hypoglycemia despite expert care.
"Although insulin therapy is life-saving, type 1 diabetes remains an extremely challenging condition to manage," Dr. Anthony S. Fauci, the NIAID director said in a press release. "For people unable to safely control type 1 diabetes despite optimal medical management, islet transplantation offers hope for improving not only physical health but also overall quality of life."
One year after their first transplant, 42 participants were free of severe hypoglycemic events, had near-normal blood glucose control and restored hypoglycemia awareness. About half of them needed to continue taking insulin to control their blood glucose levels.
Islet transplantation is an investigational therapy in the United States and the NIH says it is not appropriate for most people with type 1 diabetes because of the risks of transplant procedures, such as bleeding, and side effects of immunosuppressive medications, such as decreased kidney function and increased infections.