This study was designed to investigate the impact of the pre-operative NLR as the predictive marker of post-operative weight loss and improving diabetes in SG.
A SG, in which 80% of the stomach is removed along the greater curvature but the intestinal anatomy is unchanged, has been gaining in popularity. A SG is considered as a definitive procedure for the treatment of morbid obesity and obesity-related diseases. The number of SGs has been increasing in many countries [19–21]. A SG is successfully performed by laparoscopy in 99.7% of cases, with relative safety .
The resolution rates of obesity-related diseases in LSG were reported for: diabetes (58.6%); HT (38.8%); HL (63%); and SAS (91.2%) . Regarding the postoperative weight loss, %EWL in postoperative 1 year showed less than 50%. As one of the reasons, preoperative BMI was relatively high (average BMI; 46.7) and the ratio of super-obese patients (BMI > 50 kg/m2) was 40% (6 / 15).
A previous report discussed the mechanism of improving T2DM in bariatric surgery, duodenal-jejunal bypass (DJB) enhanced GLP-1 secretion through increased bile acids and the proliferation of L cells . The authors also reported that DJB changed the composition of gut microbiota and these changes might contribute to some of the benefits of DJB . Ryan KK, et al. reported that bile acids and the bile acid receptor, known as the farnesoid X receptor (FXR) were important molecular targets for the beneficial effects of bariatric surgery .
The ABCD score has been well-known as a predictor of the success of T2DM treatment after LSG. In this report, the authors would only recommend LSG for the T2DM patients with an ABCD > 4 . Regarding the predictor of post-operative weight loss after LSG, Seki, et al. reported that the %EWL in the super morbid obesity group (50 ≤ BMI) was significantly lower than that in the mild obesity group (BMI < 35) and reference group (35 ≤ BMI < 50) . However, the ABCD score and pre-operative BMI have no relationship with the resolution of T2DM and post-operative weight loss in the authors’ study. In that study, a low pre-operative NLR correlated with the improvement of T2DM and %EWL ≥ 50 in one (1) year post-operative in SG. Therefore, the pre-operative NLR may be the only predictive marker of post-operative weight loss and improving T2DM in SG.
A high fat diet elevated the intestinal inflammatory cytokine, alongside compromised mucosal barrier integrity with a loss in the tight junction protein (claudin-1) and increased the severity of colitis, which leads to insulin resistance due to inflammation of the liver and adipose tissue . The authors reported that DJB surgery maintained gut permeability through the suppression of gut inflammation. Therefore, DJB might improve insulin resistance by the suppression of inflammation in insulin-target tissue such as the liver and adipose tissue . The role of the NLR was reported to be a marker of intestinal inflammation because it reflected changes in the gut microbiota . Nlrp3 inflammasome sensed the obesity–associated danger-signals and contributed to the obesity–induced inflammation and insulin–resistance . So, the state of pre-operative inflammation may correlate with post-operative weight loss and glucose tolerance. Therefore, the pre-operative NLR may reflect pre-operative intestinal and systemic inflammation and contribute to post-operative weight loss and the resolution of T2DM in SG.
Our study had the limitation that this was not a long-term result especially for weight loss and reversal of co-morbidities. The results were relatively short term for follow up. Further studies are necessary to confirm whether this is a long-term relationship.