Do exist specific predictors of outcome in terms of long-term weight-loss after bariatric surgery? Visceral adipose tissue adiponectin and serum triglycerides can predict excess weight loss after bariatric surgery in female subjects with severe obesity.

Objective: Bariatric surgery does not always result in satisfactory excess weight loss (EWL) in severe obesity. Given the economic and clinical costs of bariatric surgery failure, defining predictors of successful EWL represents a relevant clinical issue for the health system to select patients enefiting from operation. Methods: From September 2017 to 2021 130 severe obesity patients undergoing laparoscopic bariatric surgery were enrolled. Pre-surgery valuations included anthropometrics and biochemical analyses.. Follow-ups occurred at 6, 12, 18, and 24 months, tracking weight, BMI, and comorbidities. Statistical correlation was performed in order to find a predictor of EWL after Surgery. Furthermore, we built a pilot study involving a ubgroup of43 patients investigating adiponectin levels in subcutaneous (SAT) and visceral adipose tissue (VAT) samples that were obtained during bariatric surgery. We analyze possible clinical parameter predictors assessed at baseline of EWL at different times of follow up. In a subgroup of 43 patients, by ELISA and Western blot analyses, we assessed the predicting value of pre-operative adiponectin (APN) locally produced in abdominal visceral (VAT) and subcutaneous (SAT) adipose tissue versus plasma levels as a novel sex-linked biomarker of EWL at different time points of follow up (6-24 months) after bariatric surgery. Results: In the entire cohort, we found at multivariate analysis HbA1 and NASH as well as triglycerides as good independent predictors of EWL at short and long time intervals, respectively, and only in female subjects. In the subgroup of operated patients where tissue adiponectin was available, we found that VAT-APN was lower in females and represented the only marker significantly orrelated with EWL. In females, VAT-APN in the distribution upper quartile but not baseline BMI retained a statistically significant correlation with WL at any time points (6-24months) at multivariate analysis. The best VAT-APN cut-off value to predict 95% EWL at 12 months from surgery (98% accuracy, 100% sensitivity, 94% specificity, p=0.010) was 5.1μg/mg. Conclusions: In conclusion, our findings indicate that in females affected by severe obesity, novel predictors of EWL can be identified. In particular, APN produced in the abdominal VAT rather than its circulating or subcutaneous levels can predict EWL after bariatric surgery as an independent factor only in the female sex. Similarly, basal TG and HBA1c, as well s NASH revealed to be putative factors that can predict EWL in females subjects thus contributing to better identify those patients who could much benefit from surgery.