ESPE Abstracts

Background: Pancreatogenic diabetes is rare in children. The prevalence is 5–10% of all cases of diabetes in the developed world. The underlying pathophysiology is destruction of islet cells by pancreatic inflammation.

Case: A 15-year old previously healthy boy presented with polyuria, polydipsia, abdominal pain and loss of weight (LOW) over several weeks. Family history revealed a three-generational history of diabetes including reported type-1 (T1DM) and type-2 diabetes mellitus (T2DM). On examination he had mild epigastric tenderness, with moderate dehydration. His initial blood tests showed hyperglycaemia and high HbA1C (Table 1). An oral glucose tolerance test (OGTT) showed baseline BG (7.3 mmol/L) and c-peptide (274 pmol/L) both rising after 2-hour (BG 18.8 mmol/L and c-peptide 498 pmol/L). Diabetes autoantibodies (Islet cell, Islet antigen 2, and Glutamic acid decarboxylase) were negative. The results confirmed diabetes but not conclusive of either T1DM or T2DM. He was started on subcutaneous insulin (Glargine and NovoRapid®). Next generation sequencing for all known monogenic diabetes genes was negative. In the following weeks the patient complained of possible symptoms of gastric outlet obstruction (GOO) with on-going central abdominal pain, LOW (8 kg over 6 weeks), early satiety and pain on eating larger portions. A repeat amylase was very high (415 IU/L) and an abdominal MRI revealed a large pancreatic pseudocyst with pancreatic duct disruption. This confirmed diabetes secondary to chronic pancreatitis - also referred to as type 3c diabetes mellitus (T3cDM) or pancreatogenic diabetes. Bloods for fat soluble vitamins (A, D and E) confirmed vitamin D deficiency, and he was commenced on vitamin D supplementation. His clotting profile was normal. Following endoscopic drainage of the pseudocyst his symptoms of GOO quickly resolved. His insulin requirement is slowly weaning. Further tests looking at genetic causes for idiopathic pancreatitis (SPINK1 and PRSS1 genes) were negative.

Discussion: T3cDM is a complex condition which unlike T1DM or T2DM is often complicated by co-morbidities such as malabsorption and malnutrition. It is mis-diagnosed as T2DM in over 87% of patients. Making the diagnosis of T3cDM is important in order to appropriately manage both the exocrine and endocrine pancreatic insufficiency. Patients with T3cDM require insulin therapy more urgently than those with T2DM. Hence early pancreatic imaging is recommended in suspected cases. Avoiding alcohol and smoking will reduce pancreatic inflammation. Oral pancreatic enzyme supplementation may be required.