Objective: Gallbladder hypomotility in celiac disease has been attributed to decreased cholecystokinin secretion. The possible influence of somatostatin, which inhibits gallbladder motility, however, has never been evaluated. In this study gallbladder emptying and cholecystokinin and somatostatin plasma levels were evaluated in response to a fatty meal in patients with celiac disease at diagnosis and after long-term gluten-free diet and in controls.
Methods: Gallbladder volume and plasma levels of cholecystokinin and somatostatin were measured by ultrasonography and radioimmunoassay, respectively, at 0 time and 30, 60, 75, and 90 min after an oral fatty meal (227 kcal, 45% fat) in 10 celiac patients at diagnosis and after 18 months of successful gluten-free diet and in 10 healthy subjects. The pattern of gallbladder emptying was evaluated by mixed factorial analysis of variance and the curve fitting by multiple regression analysis.
Results: Patients at diagnosis had significantly greater fasting gallbladder volume and higher somatostatin plasma levels than controls (25.7 +/- SD 9.7 ml vs 16.8 +/- 7.0 ml, p = 0.021 and 9.3 +/- 4.6 vs 4.8 +/- 3.4 pmol/L, p = 0.023, respectively), significantly lower fatty meal-induced gallbladder ejection fraction (55 +/- 11.2% vs 76 +/- 7.2%, p = 0.005), and cholecystokinin peak and smaller area under the cholecystokinin secretion curve (3.1 +/- 2.3 pmol/L vs 10.5 +/- 6.9 pmol/L, p = 0.028 and 157 +/- 142 pmol/L/90 min vs 453 +/- 229 pmol/L/90 min, p = 0.028, respectively). The two groups had a similar emptying pattern (p = 0.8913) expressed by a significant quadratic term of the emptying function (p = 0.0001). The mean overall emptying volume was significantly greater in patients than in controls (p = 0.0007). Gluten-free diet normalized these findings.
Conclusions: In patients at diagnosis, elevated somatostatin levels were associated with increased gallbladder fasting volume, whereas decreased cholecystokinin secretion was responsible for the reduced gallbladder emptying. Gluten-free diet reversed these abnormalities.