Association of Weight Loss with Gallstone Formation Following Sleeve Gastrectomy: A Retrospective Cohort Study.

BACKGROUND

Sleeve gastrectomy has become a widely performed metabolic bariatric procedure for managing obesity. However, rapid weight loss after SG has been associated with the formation of de novo gallstones. Understanding this relationship is critical for optimizing patient outcomes.

OBJECTIVE

To assess the association between weight loss and de novo gallstone formation in adults undergoing SG.

METHODS

We retrospectively analyzed 386 adults who underwent SG at a private clinic in Lima, Peru, and were followed for 12 months. Gallstone formation was defined as the presence of stones in the gallbladder confirmed by abdominal ultrasound with no prior evidence before surgery. Weight loss markers included absolute weight loss (AWL), percentage of excess weight loss (PEWL), absolute BMI loss (ABMIL), and percentage of excess BMI loss (PEBMIL). Relative risks (RR) with their corresponding 95% confidence intervals (CI) were calculated using generalized linear models from the Poisson family with a logarithmic link function and robust variances.

RESULTS

The mean age of the patients was 36.4 years, and 68.1% were female. The means for AWL, PEWL, ABMIL, and PEBMIL were 29.1 kg, 28.1%, 10.7 kg/m, and 27.8%, respectively. In the multivariable model, neither AWL (aRR 0.99; 95% CI 0.97-1.02; p = 0.712), PEWL (aRR 0.98; 95% CI 0.93-1.01; p = 0.075), ABMIL (aRR 0.97; 95% CI 0.91-1.04; p = 0.465) nor PEBMIL (aRR 0.97; 95% CI 0.94-1.01; p = 0.079) were associated with the occurrence of de novo gallstones.

CONCLUSION

Markers of absolute weight loss, percentage of excess weight loss, absolute BMI loss, and percentage of excess BMI loss were not associated with post-sleeve gastrectomy gallstone formation.