Pancreatic diabetes is believed to be an irreversible sign of progressive pancreatic failure (1). We report here on a girl with chronic hereditary pancreatitis and the R122H-mutation of the cationic trypsinogen gene (2), in whom pancreatic diabetes regressed in the course of the disease.

The girl initially presented at 6.3 years of age with acute pancreatitis. Episodes of diarrhea occurred shortly after initial presentation. The cholecystokinin-secretin stimulation test revealed global exocrine insufficiency. Oral pancreatic enzyme supplementation was initiated with porcine pancreatic extracts. Until the age of 12.2 years, four hospital admissions because of acute pancreatitis were necessary. Already the initial abdominal ultrasound revealed pancreatic calcifications and a dilated main duct. Patients with early calcifying disease develop diabetes frequently; severe exocrine insufficiency is associated with subsequent pancreatic diabetes as well (3,4). Thus, our patient carried both risk factors of early pancreatic diabetes. Initially, oral glucose tolerance test and HbA1c (A1C) were normal. At 7.8 years, oral glucose tolerance test with 1.75 g/kg glucose revealed 10.8 mmol/l glucose at 120 min (diabetes >10.1 mmol/l). The fasting C-peptide dropped to 0.14 nmol/l, which is markedly below the normal range (0.25–1.3 nmol/l). A1C was elevated to 6.3% (normal range 4.8–6.0%). Under the suspicion of pancreatic diabetes, conventional insulin therapy was initiated (0.2 IE insulin · kg−1 · day−1). Daily insulin requirements declined under fat-restricted and complex carbohydrate–enriched diet. Insulin therapy was stopped at 13.5 years of age. The 120-min glucose concentration dropped to 7.4 and 5.9 mmol/l at 14.9 and 17 years of age, respectively. The corresponding C-peptide levels restored to 0.63 and 0.62 mmol/l, respectively. This corresponds with a more than fourfold increase as compared with the time of diagnosis of pancreatic diabetes. All pancreatic endocrine function tests have been performed at least 6 weeks after a pancreatitis attack when the patient was in stable clinical condition.

Later endoscopic pancreatic duct decompression did not further improve endocrine and exocrine insufficiency.

During the following years, she grew along the 50th percentile, and her weight followed the 75th percentile. Fasting glucose was between 4.5 and 5.1 mmol/l.

Prospective investigations of patients with pancreatic diabetes are warranted to analyze the main endocrine contributors of the phenomenon of recovered glucose tolerance. Is it fluctuating insulin and glucagon reserves alone or are further hormones involved (e.g., during puberty)? So far, it seems patients with insulin-dependent pancreatic diabetes should be carefully observed for fluctuating glucose homeostasis. In some cases, termination of insulin therapy could be possible and may prevent side effects of nonmandatory exogenous insulin supplementation.

Sjoberg RJ, Kidd GS: Pancreatic diabetes mellitus.
Diabetes Care
Whitcomb DC, Gorry MC, Preston RA, Furey W, Sossenheimer MJ, Ulrich CD, Martin SP, Gates LK Jr, Amann ST, Toskes PP, Liddle R, McGrath K, Uomo G, Post JC, Ehrlich GD: Hereditary pancreatitis is caused by a mutation in the cationic trypsinogen gene.
Nat Genet
Malka D, Hammel P, Sauvanet A, Rufat P, O’Toole D, Bardet P, Belghiti J, Bernades P, Ruszniewski P, Lévy P: Risk factors for diabetes mellitus in chronic pancreatitis.
Lankisch PG, Löhr-Happe A, Otto J, Creutzfeldt W: Natural course in chronic pancreatitis: pain, exocrine and endocrine pancreatic insufficiency and prognosis of the disease.