Rationale and objectives: Reports on the effect of the ovulatory cycle on gallbladder motility are inconsistent. The authors investigated the gallbladder motor function at both phases of the menstrual cycle in humans.
Methods: Seventeen young, healthy, nulliparous women participated in the study. Gallbladder fasting volume and postprandial emptying were measured twice in each subject using real-time ultrasonography: one at the follicular (12th-13th day) and another at the luteal (21st-22nd day) phases. From the emptying curves, the duration of the lag phase and the ejection fraction of emptying were calculated.
Results: Fasting volume was significantly greater (P = 0.025) at the luteal (14.8 +/- 8 mL standard deviation [SD]) than at the follicular (11.2 +/- 4.7 mL SD) phase. Although the lag phase duration was longer (P = 0.009) at the follicular (5.2 +/- 6.4 SD minutes) than the luteal (1.6 +/- 3.6 minutes SD) phase, the ejection fraction was significantly greater at the latter one (follicular phase: 62 +/- 13.2% SD; luteal phase: 73.4 +/- 14% SD; P = 0.0085).
Conclusions: Female sex hormones seem to biologically affect the gallbladder motor function.