Differences in the natural history of idiopathic (nonalcoholic) and alcoholic chronic pancreatitis. A comparative long-term study of 287 patients.

Controversies in the literature regarding definition, diagnosis, and therapy of chronic pancreatitis may be related in part to differences in the natural history of alcoholic and idiopathic (nonalcoholic) chronic pancreatitis. In order to evaluate this problem the long-term course of 205 patients with alcoholic (85.4% with calcifications) (group A) and 82 patients with idiopathic (nonalcoholic) chronic pancreatitis (76.8% with calcifications) (group B) has been analyzed prospectively since 1963. The patients were studied at regular intervals with particular regard to pain, pancreatic exocrine, and endocrine function and calcifications. The observation time was 2 years or longer in 230 patients with a median observation time of 6.7 years from diagnosis in group A and 10.6 years in group B. In group B over 50% of the cases had primary painless chronic pancreatitis. Progressive deterioration of exocrine and endocrine function was observed in both groups. However, in group A the rate of progression of exocrine dysfunction after diagnosis was more rapid and the incidence of diabetes in relation to marked exocrine insufficiency was much higher than in group B. Steatorrhea preceded diabetes in 56% (group A) and 80% (group B), respectively. Onset of pancreatic calcifications was closely associated with pancreatic exocrine insufficiency in group A in contrast to group B. In addition lasting pain relief occurred spontaneously in about 30% of patients in group B despite a normal exocrine function for 6 years or longer which is in disaccord with the results in alcoholic chronic pancreatitis. In conclusion group A and B have many features in common, in particular the high incidence of pancreatic calcifications and the progressive pancreatic dysfunction. However, the long-term profile of both groups differs in some important aspects, particularly in the clinical pattern and in the rate of progression of pancreatic dysfunction and morphology. These differences should be appreciated in the discussion of problems regarding definition, diagnosis, and surgical therapy of chronic pancreatitis.