Diagnosis and treatment of diabetes mellitus in chronic pancreatitis

Diabetes secondary to pancreatic diseases is commonly referred to as pancreatogenic diabetes or type 3c diabetes mellitus. It is a clinically relevant condition with a prevalence of 5%-10% among all diabetic subjects in Western populations. In nearly 80% of all type 3c diabetes mellitus cases, chronic pancreatitis seems to be the underlying disease. The prevalence and clinical importance of diabetes secondary to chronic pancreatitis has certainly been underestimated and underappreciated so far. In contrast to the management of type 1 or type 2 diabetes mellitus, the endocrinopathy in type 3c is very complex. The course of the disease is complicated by additional present comorbidities such as maldigestion and concomitant qualitative malnutrition. General awareness that patients with known and/or clinically overt chronic pancreatitis will develop type 3c diabetes mellitus (up to 90% of all cases) is rather good. However, in a patient first presenting with diabetes mellitus, chronic pancreatitis as a potential causative condition is seldom considered. Thus many patients are misdiagnosed. The failure to correctly diagnose type 3 diabetes mellitus leads to a failure to implement an appropriate medical therapy. In patients with type 3c diabetes mellitus 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.