According to a new study, about 1/3 of people with type 1 diabetes produce insulin, as measured by C-peptide, even upward of 40 years from initial diagnosis…
The findings shed new light on the long-accepted belief that patients with type 1 diabetes lose all ability to produce any insulin.
The study confirmed that C-peptide is present in patients across a wide age spectrum, with greater frequency and higher values in those diagnosed as adults, compared with those diagnosed as children. They used samples from the T1D Exchange Biobank, a repository of type 1 diabetes biological samples.
This information may prevent misdiagnosing patients as type 2 diabetes when their c-peptide test comes back positive. This will also provide improved treatments to control glucose levels.
Asa K. Davis, PhD, T1D Exchange, Benaroya Research Institute, Seattle, Washington, which houses the TID Exchange Biobank added that, the data suggests important differences in the biological process of type 1 diabetes between those diagnosed as children or as adults.
“These findings lend further credence to research underway on targeted therapies that could prolong insulin production, helping patients with type 1 diabetes better manage their disease and reduce complications,” he said. “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.”
For the study, researchers measured C-peptide levels in 919 people with type 1 diabetes ranging from 3 to 80 years from diagnosis (aged 3-88 years) at 28 of T1D Exchange’s 70 Clinic Network locations. Among the participants with 3- to 5-year disease duration, C-peptide was present in 78% of patients diagnosed after age 18, and in 46% of those diagnosed before age 18.
In addition, 16% of adult-onset type 1 individuals and 6% of childhood-onset type 1 diabetes cases had residual C-peptide more than 40 years from diagnosis.
Carla J. Greenbaum, MD, Benaroya Research Institute and author of the study also added that, “Other studies have shown that some patients with type 1 diabetes 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.”
Dr. Davis added that, “Diabetologists have been, at times, confounded by the problem of patients being denied an insulin pump because their C-peptide levels defy the classic definition of the disease.” “We can now quantify the number of patients who demonstrate continued insulin production, which will lead to raised awareness among general practitioners and insurers.”
- C-peptide is present in patients across a wide age spectrum
- The information may prevent misdiagnosing patients as type 2 diabetes
- This information can also prevent patients being denied an insulin pump because their C-peptide levels.
Richard A. Oram, Most People With Long-Duration Type 1 Diabetes in a Large Population-Based Study Are Insulin Microsecretors, pub online, Diabetes Care, Dec. 17. doi: 10.2337/dc14-0871