‘Type 3c’ Diabetes Often Mislabeled as Type 2

A new study published in Diabetes Care suggests that the incidence of diabetes of the exocrine pancreas (Type 3c) is often mislabeled as type 2 diabetes. 

Type 3c diabetes occurs when a process (eg, inflammation, neoplasia, surgical resection) disrupts the pancreas and causes exocrine and endocrine dysfunction. “To our knowledge, preceding pancreatic disease has never been systematically identified in a cohort of people with diabetes in primary care, and thus the comparative incidence and clinical characteristics of diabetes of the exocrine pancreas remain uncertain,” explained lead author Chris Woodmansey. 

Researchers from the United Kingdom performed a study to examine the incidence of diabetes after pancreatic disease and how patients are classified by clinicians. They also aimed to compare the differences in characteristics with type 1 and type 2 diabetes. Over 2 million primary care records in the Royal College of General Practitioners Research and Surveillance Centre (RCGP RSC) were evaluated for cases of adult-onset diabetes from January 1, 2005 to March 31, 2016. The authors analyzed demographics, diabetes classification, glucose control, and insulin use among those with and without pancreatic disease (acute vs. chronic) prior to their diabetes diagnosis. Moreover, baseline potential risk factors for poor glycemic control (HbA1c ≥7%) and insulin requirement were controlled via regression analysis. 

Of the total records, 31,789 new diagnoses of adult-onset diabetes were identified. The data showed diabetes following pancreatic disease was more common than type 1 diabetes (2.59 [95% CI: 2.38–2.81] per 100,000 person-years vs. 1.64 [95% CI: 1.47–1.82]; P<0.001). These cases of diabetes following pancreatic disease (n=559) were primarily classified by clinicians as type 2 diabetes 87.8% of the time and as diabetes of the exocrine pancreas 2.7% of the time. 

Specifically, diabetes following pancreatic diabetes was found to be diagnosed at a median age of 59 years and was linked to poor glycemic control (adjusted odds ratio [aOR] 1.7 [95% CI: 1.3–2.2]; P<0.001) vs. type 2 diabetes. In addition, the need for insulin within 5 years was the lowest with type 2 diabetes (4.1%) compared with diabetes following acute pancreatitis (20.9%), and diabetes following chronic pancreatic disease (45.8%). 

Findings from the study show that diabetes of the exocrine pancreas “is frequently labeled type 2 diabetes but follows a different clinical course, with worse glycemic control and a markedly greater requirement for insulin. ” stated Woodmansey. Clinicians should inquire whether a patient has had any history of pancreatic disease when they first present with diabetes and take into consideration possible diabetes of the exocrine pancreas. 

“Greater awareness of diabetes of the exocrine pancreas is required to appropriately manage this diabetes subgroup.”

For more information visit diabetesjournals.org.