Pancreatogenic diabetes, also known as Type 3C diabetes, results from pancreatic disease (such as chronic pancreatitis) or surgery on the pancreas. A grayish pink gland located in the abdomen, the pancreas essentially has a dual function: The exocrine pancreas secretes important digestive enzymes into the gastrointestinal tract, while the endocrine pancreas secretes the hormones insulin and glucagon into the bloodstream to regulate carbohydrate metabolism. In diabetes, the beta cells of the pancreas no longer make enough insulin to meet the body’s needs, leading to elevated levels of glucose in the blood.
Even though diabetes is primarily a disease of the endocrine pancreas, scientists now know that diseases of the exocrine pancreas — or surgery on the pancreas — can also lead to diabetes. They have dubbed this type of diabetes pancreatogenic diabetes, or Type 3C diabetes. Chronic pancreatitis (inflammation of the pancreas), hemochromatosis (a disease of iron metabolism), cystic fibrosis (an inherited disorder of the pancreas and other exocrine glands that produces abnormally thick secretions), pancreatic cancer, and previous surgery on the pancreas have all been associated with diabetes. It is estimated that Type 3C diabetes accounts for 5% to 10% of diabetes diagnoses in western populations and that chronic pancreatitis accounts for 75% of this type of diabetes.
Scientists are still trying to figure out exactly what causes pancreatogenic diabetes. They have noted that a single genetic mutation can impair both endocrine and exocrine functions of the pancreas. Furthermore, certain pancreatic diseases can disturb the regeneration of beta cells within the pancreas that manufacture and secrete insulin, thus causing diabetes in patients with chronic pancreatitis. Scientists recommend treating this type of diabetes with metformin rather than insulin or medications that stimulate the secretion of insulin.