Gallbladder and gastric emptying: relationship to cholecystokininemia in diabetics

Background: Impaired gastrointestinal and gallbladder motility, as a complication of long-lasting diabetes mellitus, has been ascribed to the possible development of autonomic neuropathy, although the intervention of hormonal factors may not completely be excluded. In this regard, cholecystokinin (CCK), a gut hormone known to regulate pancreatic exocrine secretion, gallbladder contraction, and bowel motility in response to a meal, is impaired in patients with diabetes mellitus. This prompted us to evaluate the relationship between the plasma levels of CCK and gallbladder and gastric emptying in neuropathy-free diabetic patients treated with insulin (group A) or with oral hypoglycemic agents (group B) under basal conditions and in response to a standard test meal. Methods: Plasma CCK was measured by radioimmunoassay. Gastric and gallbladder emptying were evaluated ultrasonographically. Results: Plasma CCK levels were significantly lower in both groups of diabetics than in healthy controls during a fast and in response to a standard meal. However, meal ingestion was able to evoke a pattern of CCK response in both groups of diabetic patients similar to that seen in controls. Fasting gallbladder volume was higher in patients with diabetes than in controls, whereas the percentage of emptying was lower in patients of both groups. Gastric final emptying time was significantly longer in both groups of diabetics than in controls. Conclusion: This study shows that patients with diabetes have lower plasma levels of CCK, which may explain their relatively hypotonic gallbladder and reduced gastric motility.