Alterations in digestive function caused by pancreatic disease

Increased postprandial responses of GLP-1 and GIP in patients with chronic pancreatitis and steatorrhea following pancreatic enzyme substitution

We aimed to investigate how assimilation of nutrients affects the postprandial responses of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) and to evaluate the effect of pancreatic enzyme substitution (PES) on insulin secretion in patients with chronic pancreatitis (CP) and pancreatic exocrine insufficiency (PEI). Eight male patients with CP and PEI were studied. Blood was sampled frequently on two separate days after ingestion of a liquid meal with and without PES, respectively. Eight healthy male subjects served as a control group. beta-Cell responsiveness was estimated as changes in insulin secretion rates in response to changes in postprandial plasma glucose (PG). There was no difference in the PG incremental area under curve (AUC) for patients with and without PES [406 +/- 100 vs. 425 +/- 80 mM.4 h (mean +/- SE), P = 0.8]. The response of total GLP-1 was higher after PES (AUC: 7.8 +/- 1.2 vs. 5.3 +/- 0.6 nM.4 h, P = 0.01), as was the response of total GIP (AUC: 32.7 +/- 7.5 vs. 21.1 +/- 8.3 nM.4 h, P = 0.01). Concurrently, both plasma insulin, plasma C-peptide, and total insulin secretion increased after PES (AUC: 17.7 +/- 4.2 vs. 13.6 +/- 2.9 nM.4 h, P = 0.02; 237 +/- 31.4 vs. 200 +/- 27.4 nM.4 h, P = 0.005; and 595 +/- 82 vs. 497 +/- 80 pmol.kg(-1).4 h, P = 0.01, respectively). beta-Cell responsiveness to glucose was not significantly different on the two study days for patients with CP. These results suggest that the secretion of GLP-1 and GIP is under influence of the digestion and absorption of nutrients in the small intestine and that PES increases insulin secretion.

Pancreatic exocrine and endocrine function after operations for chronic pancreatitis

Exocrine and endocrine function of the pancreas was assessed in the early postoperative period (< or = 2 months) and subsequently (mean, 25 months; range, 3 to 120) in 103 patients (69 men, 34 women; mean age, 42.4 +/- 11.6 years) undergoing operation for chronic pancreatitis. Alcohol was the main causative agent (69%) and pain the most frequent indication (87%) for operation. Drainage procedures (n = 23) did not alter pancreatic function either initially or on long-term follow-up. In the early postoperative period, distal pancreatectomy (n = 42) often impaired endocrine function without affecting exocrine function; seven patients (17%) became diabetic, and results of oral glucose tolerance test showed deterioration in 23 of 28 patients (82%, p < 0.05). On subsequent follow-up, 11 patients developed exocrine failure (p < 0.01) and 10 patients endocrine (p < 0.01) failure. Proximal pancreatectomy (n = 38) precipitated clinical exocrine failure in 14 patients (37%, p < 0.01), yet pancreolauryl tests in 18 patients showed little objective change in exocrine status (0.50 > p > 0.10). Endocrine function was initially spared after proximal pancreatectomy, but six additional patients (16%, p < 0.05) required treatment for diabetes at a mean of 19 months (range, 3 to 34). Deterioration in pancreatic function is thus not an invariable immediate consequence of pancreatic drainage procedures or partial pancreatectomy for chronic pancreatitis. Progression of disease must account, in part, for failure of both exocrine and endocrine function on long-term follow-up. Drainage operations appear to delay this progressive decline in pancreatic function.