Type 3C Diabetes: What You Need to Know

Do you know what type 3C diabetes is? We'll show you what the experts know about it and how it can be treated.
Type 3C Diabetes: What You Need to Know

Last update: 16 December, 2022

Almost everyone is familiar with three types of diabetes: type 1 diabetes, type 2 diabetes, and gestational diabetes. The truth is that there are also other manifestations of this disease, among which type 3C diabetes stands out. Although it isn’t as well known by the general public, it’s well cataloged and studied in the medical world.

As experts point out, this type of diabetes has been known historically as pancreatogenic or pancreatogenic diabetes mellitus. However, in recent years, medical literature has decided to call it type 3C diabetes. Although less common, some also call it diabetes due to diseases of the exocrine pancreas. We’ll review its causes, symptoms and treatment in this article.

Causes of type 3C diabetes

Type 3C diabetes doesn’t refer to just one homogeneous entity. It’s actually the outcome of a group of conditions or diseases that attack the pancreas. Indeed, this type of diabetes occurs when the pancreas stops producing enough of the hormone insulin; and it does so because something gets in the way of its natural functioning.

This type of diabetes is recognized by the World Health Organization (WHO) and the American Diabetes Association (ADA). In the cited document, the WHO points out that any condition that causes sufficient damage to the pancreas can lead to diabetes. We’ll leave you with a list of the most frequent causes of pancreatic diabetes:

  • Pancreatitis (acute, recurrent, and chronic)
  • Pancreatectomy
  • External traumas in the organ
  • Neoplasms
  • Pancreatic ductal adenocarcinoma
  • Cystic fibrosis
  • Hemochromatosis
  • Fibrocalculous pancreatopathy
Type 3C diabetes can be caused by pancreatitis
There are a large number of medical conditions that can lead to type 3C diabetes.

Not all patients who develop these complications will contract diabetes. According to some estimates, 78.5% of episodes are related to chronic pancreatitis. This is due, as we have already stated, to the fact that the damage must be significant and extend throughout the entire organ (or a large part of it) in order to interfere with the production of insulin.

It is believed that up to 10% of patients with diabetes in Western societies have this type of diabetes. It is, therefore, an underdiagnosed disease, and one that is often confused with type 2 diabetes. In the case of chronic pancreatitis, type 3C diabetes arises as a consequence of the destruction of islet cells by pancreatic inflammation.

Damage to the organ also causes malabsorption of nutrients, which in turn results in impaired incretin production. This alteration causes a lower release of insulin from the remaining beta cells. The process is different from other types of diabetes, which is why it warrants an independent classification.

Symptoms of type 3C diabetes

Most patients with this type of diabetes develop exocrine pancreatic insufficiency (EPI). In very simple terms, it refers to the inability of the pancreas to fulfill its functions. In these contexts, you may suffer the following:

  • Diarrhea or greasy or very oily stools
  • Abdominal distension
  • Flatulence
  • Stomach pain
  • Weight loss for no apparent reason
  • Fatigue or tiredness

It’s also likely that you will develop typical symptoms of diabetes, although these usually appear shortly after those listed. Thirst, increased frequency of urination, blurred vision, numbness in the feet, and ulcers that are slow to heal are the most common.

Since it’s triggered as a consequence of damage to the pancreas, its indicator symptoms are the basis for its diagnosis.

Diagnosis of type 3C diabetes

Type 3C diabetes has several diagnostic methods
Apart from detecting altered blood glucose levels, the diagnostic complexity of type 3C diabetes refers to the cause of this condition.

As the experts rightly point out, diagnosing type 3C diabetes can be tricky. This is due to the lack of knowledge on her part among health professionals, partly due to the dichotomy of the diagnosis of type 1 diabetes/type 2 diabetes.

If there’s evidence of symptoms that point to dysregulation of pancreatic function along with the typical symptoms of diabetes, its possible diagnosis should be considered.

All patients with chronic pancreatitis should be monitored in order to detect if they have type 3C diabetes or not, as well as all those who suffer from a moderate or severe condition or disease in this organ. Fasting glucose and HbA1c tests should be carried at least once a year in these patients. The most important criteria during diagnosis are the following:

  • The presence of exocrine pancreatic insufficiency (monoclonal fecal elastase-1 test or direct function tests).
  • Pathologic pancreatic imaging (endoscopic ultrasound, magnetic resonance imaging, and computed tomography).
  • The absence of autoimmune markers associated with type 1 diabetes mellitus.

Along with these, some secondary criteria can be considered, among which we highlight the absence of pancreatic polypeptide secretion, low serum levels of fat-soluble vitamins, impaired beta cell function, impaired incretin secretion, and insulin resistance.

Treatment options

Treatment of type 3C diabetes varies according to severity. Many patients develop what is known as brittle diabetes; that is, frequent episodes of severe hypoglycemia. As with type 1 and 2 diabetes, the goal of treatment is to maintain HbA1c < 7% to avoid complications in the body. Experts recommend the following:

  • Lifestyle modifications: Such as quitting smoking, minimizing (or completely eliminating) alcohol intake, and getting at least 150 minutes of moderate aerobic exercise per week.
  • Nutrition: In principle, you should eat foods rich in soluble fiber and low in fat. A balanced diet without restriction in caloric or carbohydrate intake (at least initially) is recommended. It’s also chosen to supplement the diet with fat-soluble vitamins.
  • Antihyperglycemic agents: Not all patients need their intake, but, in some contexts, metformin and thiazolidinediones may be prescribed.
  • Total pancreatectomy with autoislet transplantation: In severe cases of organ damage, transplantation options may be considered. It isn’t a first-choice therapy, and is almost always chosen when there’s a chance of developing cancer.

The available alternatives depend on the damage to the organ, and this is what determines the action to take after diagnosis. Don’t be shy about asking the medical experts all the questions you need, and don’t stop attending your regular appointments. If it’s detected early, complications will be minor.



  • Ewald N, Hardt PD. Diagnosis and treatment of diabetes mellitus in chronic pancreatitis. World J Gastroenterol. 2013;19(42):7276-7281.
  • Ewald N, Bretzel RG. Diabetes mellitus secondary to pancreatic diseases (Type 3c)–are we neglecting an important disease? Eur J Intern Med. 2013 Apr;24(3):203-6.
  • Ewald N, Kaufmann C, Raspe A, Kloer HU, Bretzel RG, Hardt PD. Prevalence of diabetes mellitus secondary to pancreatic diseases (type 3c). Diabetes Metab Res Rev. 2012 May;28(4):338-42.
  • Hart, P. A., Bellin, M. D., Andersen, D. K., Bradley, D., Cruz-Monserrate, Z., Forsmark, C. E., … & Chari, S. T. Type 3c (pancreatogenic) diabetes mellitus secondary to chronic pancreatitis and pancreatic cancer. The lancet Gastroenterology & hepatology. 2016;1(3): 226-237.
  • Makuc J. Management of pancreatogenic diabetes: challenges and solutions. Diabetes Metab Syndr Obes. 2016;9:311-315. Published 2016 Aug 25.

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