About 1 in 3 people who have Type 1 diabetes still produced insulin years after their diagnosis, according to a new, first-of-its-kind study.

The findings, published in Diabetes Care, contradict the previous understanding that the body stops creating insulin entirely in Type 1 patients. This could mean that Type 1 diabetes is more like Type 2 diabetes than once believed, as people with Type 2 diabetes lack the ability to use insulin properly, a complication called insulin resistance.

Type 1 patients have byproduct of insulin

Analyzing 919 people with Type 1 diabetes, researchers from Benaroya Research Institute Virginia Mason examined a byproduct of insulin production called C-peptide. They found that C-peptide was present in patients across all age groups, though adults tended to display the byproduct more than children. The results underscore that residual insulin production may be quite common, which could potentially lower the risk of misdiagnosis of Type 2 diabetes. The study also highlights key differences in the biological process between children and adults with the same form of the blood glucose disease.

"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," Dr. Asa K. Davis, T1D Exchange program manager at Benaroya Research Institute, said in a press release. "We can now quantify the number of patients who demonstrate continued insulin production, which will lead to raised awareness among general practitioners and insurers."

About 16 percent of adult-onset Type 1 individuals and 6 percent of childhood-onset Type 1 diabetes had residual C-peptide more than 40 years after diagnosis, Davis discovered.

A new subset

The results come in the wake of other information that is surfacing about Type 1 diabetes. Only a decade ago, Type 1 diabetes was simply known as juvenile diabetes because it was typically diagnosed in children and young adults. That diagnosis was expanded to adults who displayed the same disease. Now, though the classic definition of Type 1 says patients produce no insulin, this new research indicates that many patients still do.

"Other studies have shown that some type 1 diabetes patients who have lived with the disease for many years continue to secrete insulin and the assumption has been that these patients are exceptional," said senior author Carla J. Greenbaum, M.D., director, T1D Exchange Biobank Operations Center at the Benaroya Research Institute. "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."

So, how does this news affect you? It may lead to improved treatments to control glucose levels in people with Type 1 diabetes. Roughly 35 million people worldwide live with the disease, many of whom are children. According to the press release, the research could open doors for new ways that doctors can approach the disease, targeting different problems and aiming at new solutions.

For more on type 1 diabetes:

Type 1 Diabetes: Treatments and Drugs
Aging and Type 1 Diabetes
Can Type 2 Diabetes Turn into Type 1?