C-peptide production and beta cell functioning detected decades after disease onset
Massachusetts General Hospital (MGH) research has found that insulin production may persist for decades after the onset of type 1 diabetes. Beta cell functioning also appears to be preserved in some patients years after apparent loss of pancreatic function. The study results appear in the March issue of Diabetes Care.
"Traditionally, it was thought that beta cell function completely ceased in patients with advanced type 1 diabetes. However, data from this study and others suggest that the pancreas continues to function at some level even decades after the onset of type 1 diabetes," says Denise Faustman, MD, PhD, director of the MGH Immunobiology Laboratory, who led the study.
In the current study, blood samples from 182 individuals with type 1 diabetes were evaluated using an ultrasensitive assay for C-peptide, a marker of insulin secretion, to test for residual beta cell function. The study revealed that C-peptide production can persist for decades after disease onset and remains functionally responsive to blood sugar levels. Although C-peptide levels were lower among those who had longer duration of diabetes, the decrease over time was gradual and not the abrupt decline predicted by the conventional picture of type 1 diabetes. Even among patients with disease duration of 31 to 40 years, 10 percent still produced C-peptide. In addition, beta cell functioning remained intact at very low C-peptide levels.