CIRCULATING GASTROINTESTINAL HORMONE ABNORMALITIES IN PATIENTS WITH SEVERE IDIOPATHIC CONSTIPATION

Objective: This study aimed to determine if there is an abnormality of circulating gastrointestinal hormones in patients with severe idiopat hic constipation. Methods: Twelve patients, all female (median age 34 yr) and 12 healthy controls (eight female, median age 32 yr) were stud ied. A radioisotope-labeled solid/liquid meal was ingested, and the se rum hormone response, as well as the relationship between serum hormon es and rates of gastric emptying and small intestinal transit, were st udied for 180 min postprandially. Results: Somatostatin levels were hi gher in patients with constipation (basal level, controls vs patients, 31 vs 57 pmol/L, p < 0.05, median values; peak level, 48 vs 60,p < 0. 05). Patients showed a significantly lower somatostatin integrated inc remental meal response (2182 vs 104, p < 0.05). No correlation was fou nd between the somatostatin levels and rates of upper gastrointestinal transit in patients. Pancreatic glucagon was significantly decreased (p = 0.04). Enteroglucagon levels were significantly lower (p > 0.05) in patients between 30 and 60 min after the meal. The peak found after the meal in normal subjects was absent. Basal levels of pancreatic gl ucagon correlated with small bowel transit by two different measures: head of meal (r = 0.69, p = 0.03) and cecal filling at the time of 50% gastric emptying (r = 0.84, p = 0.002). No significant differences be tween the two groups could be found for basal and peak levels at diffe rent times and integrated incremental response to the meal for insulin , gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1 ), cholecystokinin (CCK), gastrin, pancreatic polypeptide (PP), motili n, neurotensin, and peptide tyrosine tyrosine (PYY). Conclusion: Patie nts with severe idiopathic constipation have specific abnormalities of circulating gut hormones that most likely play a role in gastrointest inal motility and that may be of pathophysiological significance. (Am J Gastroenterol 1998;93: 1351-1356. (C) 1998 by Am. Coil. of Gastroent erology).