Gallbladder pathology in morbid obesity.

Background: Obese patients are at increased risk for biliary disease. The prevalence and type of gallbladder pathology in morbidly obese patients was evaluated, and compared with a non-obese control group.

Methods: A consecutive series of obese patients (n=478) who had undergone bariatric surgery with concurrent routine cholecystectomy and a consecutive group of organ donors (n=481) were compared. Gallbladder pathology was defined as: cholelithiasis, cholecystitis, cholesterolosis, or normal pathology.

Results: Mean age of obese patients and of donors was 42 +/- 9 and 43 +/- 17 years respectively and mean BMI was 52 +/- 10 and 27 +/- 7 kg/m2 respectively, P<0.05. There were more females in the obesity group (88% vs 47%, P<0.0001). 31% of obese patients and 7% of controls had a previous cholecystectomy (P<0.0001). 21% of the obese and 72% of the controls had normal gallbladder pathology (P<0.0001). Overall, obese patients had a higher incidence of cholelithiasis (25% vs 5%, P<0.0001), cholecystitis (50% vs 17%, P<0.0001), and cholesterolosis (38% vs 6%, P<0.0001) compared with controls. Obese patients with BMI <50 were more likely than those with BMI > or =50 to have normal gallbladder pathology (27% vs 14%, P<0.001). Female patients were more likely to have undergone previous cholecystectomy than males in both the obese group (34% vs 11%, P<0.001) and the control group (12% vs 2%, P<0.0001). Normal pathology was more common in male patients (80% vs 63%, P<0.0001) and patients <50 years (76% vs 66%, P<0.05) in the control group.

Conclusions: Obese patients have an increased incidence of benign gallbladder disease than a group of controls, and the relative risk appears to be positively correlated with the level of increase in the BMI. Obesity appears to change the effect of age and gender on gallbladder pathology.