A third of people with type 1 diabetes produce insulin years after diagnosis

Around one in three people with type 1 diabetes produce insulin for years after being diagnosed, new research suggests.
The study, published in Diabetes Care, found that C-peptide, a by-product of insulin production, continued to be produced by a third of type 1 diabetes patients even upward of forty years from their initial diagnosis.
The research challenges the generally-accepted belief that type 1 diabetes patients lose their ability to produce insulin altogether; the findings could have significant policy implications.
A large-scale, first of its kind, study examined samples from the T1D Exchange Biobank, a source of biological samples relating to type 1 diabetes. Researchers discovered that C-peptide can be found in type 1 diabetes patients across a wide age spectrum. Patients who were diagnosed as -s had greater frequency and values of C-peptide compared to those diagnosed as children.
The significance of the findings
By proving that residual insulin production can be expected in many type 1 patients, the research reduces the risk of doctors misdiagnosing the condition as type 2. Because of the long-standing belief that type 1 destroys insulin production entirely, many doctors, upon observing traces of insulin production in adults with the symptoms of type 1 diabetes, misdiagnose the condition.
Asa K. Davis, the T1D exchange program manager at Benaroya Research Institute, where the T1D Exchange Biobank is house, explained: “These findings lend further credence to research underway on targeted therapies that could prolong insulin production, helping type 1 diabetes patients better manage their disease and reduce complications.
“For example, potential immunotherapy treatments are already being studied with this goal in mind, and our findings underscore that those diagnosed at a young age may be more likely to benefit from such new approaches.”
How the study was carried out
The research was conducted by measuring C-peptide levels in 919 people with type 1 diabetes ranging from three to 80 years from diagnosis (between the ages of five to 88). 78 per cent of participants who had been diagnosed within the last three to five years and after the age of 18 still had traces of C-peptide. The figure was 46 percent in those diagnosed before 18.
Among those who had been diagnosed more than 40 years ago, the figures were 16 per cent for those diagnosed as adults and six per cent for those diagnosed as children.
Senior author Carla J. Greenbaum said: “Other studies have shown that some type 1 patients who have lived with the disease for many years continue to secrete insulin and the assumption has been that these patients are exceptional.
“For the first time, we can definitively say that these patients are a true subset of the type 1 diabetes population, which has major clinical and health policy implications.”