PSUN236 Previously Undiagnosed Hereditary Pancreatitis Presenting as New Onset Type 3c Diabetes Mellitus

BACKGROUND: Type 3c Diabetes Mellitus (DM3c) or Pancreatogenic Diabetes is defined as diabetes secondary to pancreatic disease. The most common cause of Type 3c Diabetes is chronic pancreatitis, accounting for 80% of cases.(1) Hereditary pancreatitis, with mutations such as SPINK1, CFTR, CTRC, is an underdiagnosed cause of chronic pancreatitis leading to Type 3c Diabetes Mellitus.(1) The typical disease course for hereditary pancreatitis is recurrent episodes of acute pancreatitis that leads to chronic pancreatitis.(1) The average time between hereditary pancreatitis diagnosis and development of DM3c has been shown to be 80 +/- 24 months.(1) We present a case of previously undiagnosed hereditary pancreatitis presenting as new onset Type 3c Diabetes Mellitus. CLINICAL CASE: A 33-year-old male presents with a two month history of diarrhea, epigastric pain, and weight loss. Vital signs on presentation were blood pressure 105/74, heart rate 59, BMI 13. Physical exam revealed a cachectic appearing male with epigastric tenderness. Lab-work showed blood glucose 819 mg/dL, SOsm 313 mOsm/kg, lipase 21 U/L, bicarbonate 33 mmol/L. A computed tomography (CT) of the abdomen revealed punctate pancreatic parenchymal calcifications, suggestive of chronic pancreatitis. He was admitted to general medicine for management of HHS, where he was treated with IV hydration and insulin therapy. Workup for new onset diabetes revealed a negative anti-GAD Ab <5.0 U/mL, and C peptide level 0.5 ng/mL which suggested β cell dysfunction and decreased endogenous insulin secretion. With these lab values, along with radiographic findings consistent with chronic pancreatitis, the likely driving factor for his diabetes was pancreatic disease and he was diagnosed with DM3c. Severe pancreatic disease was further shown by a reduced fecal elastase level of <50, suggesting exocrine pancreatic insufficiency. Investigating the etiology of his chronic pancreatitis, history revealed no prior episodes of acute pancreatitis or abdominal pain, and no family history of pancreatitis. Workup for common causes of pancreatitis, including alcohol use, hypertriglyceridemia, and gallstones was negative, and genetic workup was pursued. The patient was found to be heterozygous for a SPINK1 mutation, which is a known mutation in hereditary pancreatitis.(1) Therefore, hereditary pancreatitis was determined to be the likely cause of his chronic pancreatitis which led to Type 3c Diabetes Mellitus. He was started on daily insulin therapy and pancreatic enzymes for his endocrine and exocrine pancreatic dysfunction respectively, with improvement in symptoms. CONCLUSION: This is a unique case of hereditary pancreatitis presenting as new onset Type 3c Diabetes Mellitus with no prior episodes of acute pancreatitis or established diagnosis of chronic pancreatitis. REFERENCES: Ramalho, G. X., & Dytz, M. G. (2020). Diabetes of the exocrine pancreas related to hereditary pancreatitis, an update. Current Diabetes Reports, 20(6). Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.