It is well known that people suffering from chronic pancreatitis (“CP”) are at high risk of developing diabetes. Much less well know, however, is that CP leads to its own specific type of diabetes, Type 3C. An article in this month’s World Journal of Gastroenterology (available in full for free here) focuses on this phenomenon and the risks and challenges it poses.
Much less is understood about type 3c diabetes than the more common types 1 and 2. It is a disease very closely related to chronic pancreatitis — according to the authors, over 80% of cases are caused by CP, as over time CP destroys pancreatic islet cells and reduces insulin production. They report that up to 70% of patients with a confirmed diagnosis of chronic pancreatitis will develop type 3c diabetes…and the prevalence rises to 90% where there is calcification. Essentially this form of diabetes is a companion condition and should always be considered when a patient has CP.
The authors explain that type 3c is often misdiagnosed, for several reasons. First, when people present with diabetes but have not yet been diagnosed with CP, doctors often assume that it is the more common forms and don’t go on to test for CP (which, as we know, is not easy to detect). Second, since diabetes can itself lead to pancreatitis, finding the two together may prompt doctors to assume that diabetes came first. Third, there are not clear diagnostic criteria for type 3c, though the authors go on to propose a high-level list (see Table 2).
This is problematic because type 3c diabetes requires specific treatments that are different than those for types 1 and 2. And missing the diagnosis of CP means that the condition itself may go untreated. There are apparently no established guidelines for treatment of type 3c, though the topic was addressed at the 2012 PancreasFest conference. In general, the authors explain that for type 3c “treating exocrine pancreatic insufficiency, preventing or treating a lack of fat-soluble vitamins (especially vitamin D) and restoring impaired fat hydrolysis and incretin secretion are key-features of medical therapy.” The authors review the current evidence on appropriate therapies, though clearly more research is required.
Interestingly, the authors conclude that chronic pancreatitis may be considerably more common than we think. The reach this conclusion after finding that type 3c accounts for a much larger proportion of diabetes cases than originally thought — 5-10% of cases rather than traditional estimates of around 1%. Since CP accounts for 80% of those cases, there must be a lot of people with undiagnosed CP. This is apparently confirmed in autopsies; like some slow growth cancers, many people in the general population may develop CP and never know it.
One other noteworthy point in the article: In discussing the prevalence of CP, they observe that “chronic pancreatitis has previously been considered a disease of alcoholism until the discovery that it is a multifactorial disease with an impact of complex genetic genotypes, smoking, special anatomic conditions, toxic agents and autoimmunity.” As CP patients know well, many medical professionals are slow to come to this realization, attributing CP mainly to alcohol abuse.
Fortunately, there seems to be a lot of new research on pancreatitis in the last few years. This month’s issue of the World Journal of Gastroenterology alone had several insightful articles, including one on pain management discussed here. We need to make sure that doctors on the front lines are aware of these developments and treat their patients accordingly.