Abstract

Background: The influence of preoperative computed tomography (CT)-derived adipose tissue density on weight loss following bariatric surgery remains unclear. We investigated the clinical utility of CT density as a predictor of weight loss and type 2 diabetes mellitus (T2DM) remission post-bariatric surgery.
Materials and Methods: This study cohort comprised patients with morbid obesity with body mass index (BMI) > 35 kg/m2 who underwent laparoscopic sleeve gastrectomy (LSG), and patients with early gastric cancer with BMI < 25 (lean) who underwent distal gastrectomy. Immune cell profiles in visceral adipose tissue (VAT) and peripheral blood were analyzed using flow cytometry.
Results: CT density in the group with morbid obesity (n=38) was lower than that in the lean group (n=37); P < 0.05. Changes in CT density of VAT (VAT-D) and subcutaneous adipose tissue (SAT-D) in the group with morbid obesity were positively correlated with postoperative weight loss. Lower preoperative VAT-D was associated with enhanced weight loss post-surgery. Among morbidly obese patients with T2DM, low VAT-D and SAT-D groups exhibited significantly less weight loss (P < 0.05). A lower preoperative VAT-D score was significantly associated with a reduced T2DM remission rate (P < 0.05) and fewer CD56bright natural killer (NK) cells in the VAT (P < 0.05). Receiver operating characteristic analysis indicated that preoperative VAT-D predicted T2DM remission with 73% specificity and 70% sensitivity. Other NK cell phenotypes were not associated with adipose tissue CT density.
Conclusion: Preoperative adipose tissue CT density predicts the effect of LSG on postoperative weight loss and T2DM improvement. CT density may reflect the local immunological status of the VAT, particularly the distribution of NK cell subsets. Further research is required to elucidate the mechanisms by which VAT-infiltrating immune cells influence clinical outcomes following bariatric surgery.

Keywords

Computed tomography, adipose tissue density, weight loss, type 2 diabetes mellitus, laparoscopic sleeve gastrectomy, obesity