[Ultrasonographic assessment of gallbladder motility in obese subjects]

The reduction in gallbladder motility could play an important role in the pathogenesis of cholesterinic lithiasis by favouring the precipitation of cholesterol crystals, especially in obese subjects who, as is well known, present a greater biliary secretion of cholesterol. In the present study we evaluated, by ultrasonography, the emptying capacity of gallbladder following a liquid meal in 20 obese subjects (BMI 37.8 +/- 11.8 kg/m2) and in 20 control subjects (BMI 23.2 +/- 1.7 kg/m2). The base and residual volume of the gallbladder, expressed in ml, were significantly higher in the obese group than in the controls: 30.7 +/- 11.8 vs 22.0 +/- 6.7 (t = 2.88 p < 0.001) and 14.6 +/- 7.14 vs 10.2 +/- 4.7 (t = 2.14 p < 0.04), respectively. However, there was no significant difference between the percentages of gallbladder emptying in the two study groups, although in the obese subjects the minimum volume was reached at the 60th minute, while in the controls it occurred at 40 minutes. Our data, in agreement with most reports in the literature, indicate that the volume of the gallbladder is greater in obese subjects and they do not present an intrinsic defect in gallbladder contractility; therefore this condition can be excluded from the risk factors of biliary lithiasis in obese subjects.