Obesity is one of the main risk factors for gastroesophageal reflux disease (GERD). With the development of social economy, the global obesity population shows a continuous growth trend, leading to an increase in the incidence rate of GERD. Obesity, especially the central obesity, is closely related to GERD. The increase of intra-abdominal pressure caused by obesity may lead to the destruction of "anti-reflux barrier" through a variety of mechanical mechanisms, and the various cytokines produced by visceral adipose tissue in obesity population may contribute to the occurr-ence and development of GERD through various biological effects. The authors explore the mechanism of obesity in the occurrence and development of GERD from both mechanical and biological effects, aiming to help clinical physicians improve their understanding of GERD.

Objective:To investigate the changes in plasma ghrelin and influencing factors of weight loss effects after laparoscopic sleeve gastrectomy combined with fundoplication surgery (LSGFD).Methods:The retrospective cohort study was conducted. The clinical data of 115 obesity patients who were admitted to the People′s Hospital of Xinjiang Uygur Autonomous Region from April to June 2023 were collected. There were 37 males and 78 females, aged (37±9)years. Of 115 pati-ents, 93 cases undergoing laparoscopic sleeve gastrectomy (LSG) were divided into the LSG group, and 22 cases undergoing LSGFD were divided into the LSGFD group. Measurement data with normal distribution were represented as Mean± SD, and the independent sample t test was used for com-parison between groups. Count data were described as absolute numbers, and the chi-square test was used for comparison between groups. Repeated measurement data were analyzed using the repeated ANOVA, and their variances were tested using a spherical test. The Logistic regression model was used for univariate and multivariate analyses. Results:(1) Changes in preoperative and postoperative plasma ghrelin in two groups of patients. The plasma ghrelin of patients at preopera-tive and postoperative 6 months changed from (16±14)×10 2 ng/L to (10±4)×10 2 ng/L in the LSG group and changed from (12±11)×10 2 ng/L to (11±3)×10 2 ng/L in the LSGFD group. There was no significant difference in the time effect, inter group effect, and interaction effect of changes in plasma ghrelin between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=2.199, Fgroup=0.001, Finteraction=0.793, P>0.05). There was a significant difference in plasma ghrelin in the LSG group before and after surgery at 6 months ( t=4.148, P<0.05), and there was no significant difference in plasma ghrelin in the LSGFD group before and after surgery at 6 months ( t=0.622, P>0.05). (2) Changes in preoperative and postoperative weight loss and metabolic related indicators in two groups of patients. ① There was a significant difference in the time effect of changes in body mass between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=242.285, P<0.05), and there was no significant difference in the inter group effect and interaction effect of changes in body mass between the LSG group and the LSGFD group before and after surgery at 6 months ( Fgroup=1.163, Finteraction=0.606, P>0.05). There were significant differences in body mass in the LSG group or the LSGFD group before and after surgery at 6 months ( t=23.597, 14.680, P<0.05). ② There was a significant difference in the time effect of changes in body mass index (BMI) between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=382.431, P<0.05), and there was no significant difference in the inter group effect and interaction effect of changes in BMI between the LSG group and the LSGFD group before and after surgery at 6 months ( Fgroup=1.619, Finteraction=1.085, P>0.05). There were significant differences in BMI in the LSG group or the LSGFD group before and after surgery at 6 months ( t=25.645, 16.628, P<0.05). ③ There was a significant difference in the time effect of changes in excess weight loss (%EWL) between the LSG group and the LSGFD group after surgery at 1 to 6 months ( Ftime=666.136, P<0.05), and there was no significant difference in the inter group effect and interaction effect of changes in %EWL between the LSG group and the LSGFD group after surgery at 1 to 6 months ( Fgroup=0.127, Finteraction=0.498, P>0.05). ④ There was no significant difference in the time effect, inter group effect, and interaction effect of changes in fasting blood glucose between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=1.573, Fgroup=1.872, Finteraction=0.948, P>0.05). There was a significant difference in fasting blood glucose in the LSG group before and after surgery at 6 months ( t=2.675, P<0.05), and there was no significant difference in fasting blood glucose in the LSGFD group before and after surgery at 6 months ( t=1.074, P>0.05). ⑤ There were significant differences in the inter group effect and interaction effect of changes in triglyceride between the LSG group and the LSGFD group before and after surgery at 6 months ( Fgroup=8.419, Finteraction=3.180, P<0.05), and there was no significant diffe-rence in the time effect of changes in triglyceride between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=1.398, P>0.05). Results of individual effect shown that there was no significant difference in triglyceride in the LSG group or the LSGFD group before and after surgery at 3 months ( F=2.956, 3.248, P>0.05), and there were significant differences in trigly-ceride in the LSG group or the LSGFD group after surgery at 1 month and 6 months ( F=14.152, 3.477, P<0.05). There was a significant difference in triglyceride in the LSG group before and after surgery at 6 months ( t=3.164, P<0.05), and there was no significant difference in triglyceride in the LSGFG group before and after surgery at 6 months ( t=0.023, P>0.05). ⑥ There were significant differences in the time effect and inter group effect of changes in total cholesterol between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=3.662, Fgroup=7.591, P<0.05), and there was no significant difference in the interaction effect of changes in total cholesterol between the LSG group and the LSGFD group before and after surgery at 6 months ( Finteraction=0.626, P>0.05). There was a significant difference in cholesterol in the LSG group before and after surgery at 6 months ( t=3.253, P<0.05), and there was no significant difference in total cholesterol in the LSGFG group before and after surgery at 6 months ( t=1.567, P>0.05). ⑦ There were significant differences in the time effect and inter group effect of changes in uric acid between the LSG group and the LSGFD group before and after surgery at 6 months ( Ftime=15.306, Fgroup=4.244, P<0.05), and there was no significant difference in the interaction effect of changes in uric acid between the LSG group and the LSGFD group before and after surgery at 6 months ( Finteraction=0.968, P>0.05). There were significant differ-ences in uric acid in the LSG group or the LSGFG group before and after surgery at 6 months ( t=6.152, 3.660, P<0.05). (3) Analysis of influencing factors on postoperative weight loss effects. Results of multivariate analysis showed that preoperative BMI, postoperative 6 months plasma ghrelin were independent protective factors for postoperative weight loss effects ( odds ratio=0.881, 0.673, 95% confidence interval as 0.817-0.950, 0.577-0.787, P<0.05). Conclusions:The decrease in plasma ghrelin in patients after LSGFD is not as obvious as that in patients after LSG, but it can achieve the same weight loss and metabolic improvement effects as after LSG. The lower preoperative BMI and postoperative 6 months plasma ghrelin are independent protective factors for postoperative weight loss effects.