Ultrasonographic study of gall-bladder emptying in obese patients.

In order to assess gall-bladder (GB) motility in obese patients, we measured by ultrasound the GB fasting volume (FV) in 45 women (23 obese, 22 controls) and 43 men (21 obese, 22 controls). The FV was larger in obese women (45.9 +/- 21.6 cm3) than in controls (26.6 +/- 10.7 cm3) (P less than 0.001), and also in obese men (39.2 +/- 20.2 vs. 23.8 +/- 9.9 cm3) (P less than 0.01). In obese women, GB FV correlated with relative body weight. No correlation was found between GB volume and age in obese subjects. In controls, but not in obese subjects, the GB ejection fraction was significantly greater in men (65.3 +/- 19.9%) than in women (51.3 +/- 9.0%) (P less than 0.02). Gall-bladder contraction was not decreased in obese subjects vs. controls, suggesting that GB hypocontractility is not a lithogenic risk factor in obesity. The observation that GB emptying does not correlate with body weight represents another argument that obesity does not impair GB contraction.