Sonographic evaluation of gallbladder volume and ejection fraction in obese women without gallstones

Obese people have an increased incidence of gallstones. Although the exact pathogenic mechanisms of gallstone development are unknown, impaired gallbladder emptying has been suggested as a possible underlying mechanism. Our aim was to investigate this possibility by evaluating gallbladder motility and related factors in obese and nonobese women without gallstones.

This study included 79 obese women and 25 nonobese healthy women. Using real-time sonography, we evaluated fasting and postprandial (15th-, 30th-, 45th-, 60th-, 75th-, 90th-, 120th-, and 150th-minute) gallbladder volumes and ejection fractions. The smallest postprandial volume was considered the residual volume.

Mean (+/- standard deviation) fasting and residual gallbladder volumes were 43.2 +/- 18.3 cm(3) and 21.4 +/- 11.2 cm(3), respectively, in the obese women and 28.1 +/- 12.3 cm(3) and 7.9 +/- 3.4 cm(3), respectively, in the nonobese women. Maximal ejection fraction was 49 +/- 19% in obese women and 63 +/- 29% in nonobese women (p = 0.001). The fasting and residual volumes and the postprandial volumes at all time points were higher in obese women than in nonobese women (p < 0.001). In addition, 15th-, 30th-, 45th-, 60th-, 75th-, and 90th-minute postprandial ejection fractions were lower in obese women than in nonobese women (p < 0.001). Positive correlations were found between fasting gallbladder volume and body mass index and body fat weight and between residual volume and body mass index, waist circumference, body fat percentage, and body fat weight (p < 0.05 for all comparisons).

Our results show that fasting and postprandial gallbladder volumes are higher and that postprandial gallbladder motility is lower in obese than in nonobese women. There are positive correlations between fasting gallbladder volume and body weight, body mass index, and body fat weight.