Introduction

Obesity presents a significant global challenge, characterized as a complex chronic condition resulting from abnormal or excessive fat accumulation.1,2 By the year 2015, the global population witnessed an approximate count of 107.7 million children and 603.7 million adults who were afflicted by obesity.3 Obesity is strongly associated with the onset and progression of numerous illnesses,4–8 and it has become a serious threat to the health and lives of people in every country, imposing a substantial strain on public health systems across nations. Bariatric surgery frequently yields more favorable outcomes in addressing morbid obesity compared to conventional weight reduction approaches. According to a 2018 survey conducted by the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) across five branches worldwide, LSG is currently the most used form of bariatric surgery in the world, accounting for 55.4% of all bariatric procedures.9 As the amount of LSG continues to increase, the suitability of patients with mild obesity for LSG treatment has become a major concern for bariatric surgeons.

In 1991, the patients with obesity of BMI ≥ 35 kg/m2 as a criterion for bariatric surgery.10 But in 2022, the criterion for bariatric surgery suggested revising the indication for to BMI >27.5 kg/m2 in Asian populations.11 Differences in fat distribution, hormone regulation, nutrient absorption, and metabolism in individuals with obesity of various BMI,12,13 which are associated with LSG efficacy.14 More evidence is therefore needed to support the suitability of patients with low BMI for LSG treatment. The research conducted by Uri Kaplan demonstrated that patient’s preoperative BMI was an independent influence on postoperative weight change.15 Based on this premise, this study aimed to analyze patients with obesity treated with LSG in our center, to examine the effectiveness and safety of LSG in individuals with obesity who have varying BMI and the effectiveness of LSG as a treatment option for patients with a low BMI, to provide some help for future clinical work.

Methods Study Design

This retrospective study was conducted at the Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wannan Medical College. Patients who underwent LSG at our center from October 1, 2019, to May 31, 2022, were retrospectively analyzed. And follow-up deadline is May 31, 2023. Patients were classified into three groups based on their preoperative BMI, and the grouping criteria used the World Health Organization (WHO) obesity classification criteria,16 Class I: 30 ≤ BMI ≤ 34.9kg/m2; Class II: 35≤ BMI ≤ 39.9kg/m2; Class III: BMI ≥ 40kg/m2. This study was in accordance with the Declaration of Helsinki and approved by the Ethics Clerkship.

Patients

Inclusion criteria: (1) 18≤ Age≤ 60 years; (2) BMI≥30 kg/m2; (3) Type 2 diabetes (T2DM) patients still have some insulin secretion function.

Exclusion criteria: (1) BMI>60 kg/m2 or BMI<30 kg/m2; (2) severe mental or eating disorders, alcohol or drug abuse; (3) those who cannot control their own behaviour; (4) patients who are physically unable to tolerate the procedure; (5) special types of diabetes (gestational diabetes, type 1 diabetes, islet-deficient diabetes, etc.); (6) previous other bariatric surgery; (7) gastroscopy suggesting the presence of gastric ulcers; (8) patients with gastroesophageal reflux disease (GERD).

Treatment

In this study, all patients underwent LSG by the same surgical team, following the standardized LSG protocol (see Appendix Content 1). Patients fasted from water for 24 hours after surgery, with routine intravenous drips of glucose and saline during the fast, and the rest of the treatment was individualized according to the patient’s postoperative condition. If the patient does not experience severe discomfort within 24 hours following the surgery, it is recommended that they begin consuming a small quantity of water. After observing the patient for 6 hours following water intake, if there are no adverse reactions, the drainage tube will be removed and the patient will be discharged. When a patient is discharged from hospital, he is given a post-operative management guide, which details post-operative diet, exercise and review considerations. The patients were asked to undergo follow-up surveys at 1, 3, 6, and 12 months after surgery.

Outcome Measurements

General clinical indicators such as weight (kg), BMI (kg/m2), blood pressure (mmHg) and quality of life score (QOL score) were measured 1 day before surgery and at 1, 3, 6, and 12 months after surgery. The postoperative weight change expressed as the percentage of excess weight loss (%EWL) which was calculated from the postoperative follow-up data, %EWL = (initial weight - follow-up weight)/(initial weight - 25 × height2) × 100%.17 The patients’ QOL was scored using the Moorehead-Ardelt QOL II scale (scores: −3 to +3), higher scores mean better QOL.18 The standards for remission of comorbidities refer to the American Society for Metabolic and Bariatric Surgery (ASMBS).17

The blood samples used for the examination are all venous blood drawn on a fasting basis. Blood samples were used to measure fasting insulin (FINS), fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c). FBG, TC, TG, LDL-c, and HDL-c were measured using an automated biochemical analyzer. Serum concentrations of FINS were measured using an ELISA immunoassay (Sigma-Aldrich).

The primary endpoint of this study was to determine if there were variations in weight loss after surgery among patients with obesity who had different BMI and to evaluate the effectiveness of surgery in patients with Class I obesity. The secondary endpoint was the correlation between patients’ preoperative BMI and %EWL.

Statistics

The statistical analysis for this study utilized SPSS 22.0 and R (version 3.6.3). P<0.05 was employed to establish statistically significant distinctions, and all tests were conducted with two-sided analysis. Data that followed a normal distribution were presented as mean ± SD, One-Way ANOVA was employed to compare the three groups, and the Least-Significant Difference (LSD) test was used to compare the two groups. Data that did not conform to a normal distribution were expressed as M(P25, P75), and the Kruskal–Wallis H-test was used for comparison between the three groups. Utilized the chi-square test to analyze and compare the count data of the different groups. The relationship between %EWL and BMI was explored using Spearman correlation analysis and linear regression analysis.

Results Patient Characteristics

During the study period, 153 patients underwent LSG. A total of 19 patients were excluded from this study as they did not meet the inclusion criteria. Among them, 2 patients became pregnant after surgery, 1 patient was using antidepressant medication, 4 patients underwent cholecystectomy during the surgery, and 12 patients had incomplete follow-up data. Ultimately, this study included a total of 134 patients, Figure 1 shows the detailed flow chart of this study. There were 61 patients in Class I, 44 patients in Class II and 29 patients in Class III. The average weight of the patients who took part in this study was (98.62 ± 15.00) kg, their average age was (28.53±6.69) years, and their average BMI was (36.53±4.53) kg/m2. There were no statistically significant differences in the remaining baseline characteristics (P>0.05). Table 1 details the relevant preoperative data for each group and compares them.

Table 1 Baseline Characteristics of the Three Groups

Figure 1 Study flow diagram.

Post-operative weight change and comparison between three groups

At 12 months postoperatively, the mean %EWL for Class I, Class II and Class III obesity were (104.26±16.41)%, (90.36±9.98)%, and (78.30±14.64)%, respectively, with statistically significant differences between the groups (P<0.001). The mean %TWL were (24.10 ± 4.02)%, (29.92 ± 3.20)%, and (32.89 ± 7.33)%, P<0.001, as shown in Content 2: Table S1. When comparing the two groups, the mean %EWL for Class II obesity was lower than Class I obesity, and this difference was statistically significant (P<0.001). Similarly, the mean %EWL for Class III obesity was also lower than Class I obesity (P<0.001), and Class III obesity was also lower than Class II obesity (P=0.001). However, %TWL was higher in Class III and Class II obesity than in Class I obesity (P<0.001 for all). Detailed data on %EWL and %TWL over the postoperative follow-up time for the three groups are presented in Table 2 and Content 2: Table S1, respectively. Figure 2 and Content 3: Figure S1 show a comparison of %EWL and %TWL at various postoperative time points for each group.

Table 2 Comparison of the Percentage of Excess Weight Loss (%EWL) in the Three Groups After Surgery

Figure 2 Comparison of postoperative % Excess Weight Loss between the three groups at 1, 3, 6, and 12 months postoperatively. ns, P > 0.05; **P < 0.01; ***P < 0.001.

Association of %EWL and BMI

There was a negative correlation between preoperative BMI and %EWL at 1, 3, 6, and 12 months postoperatively (R= −0.344, P<0.001; R= −0.389, P<0.001; R= −0.442, P<0.001; R= −0.641, P<0.001), see Figure 3. The results of the linear regression analysis between preoperative BMI and %EWL at 1, 3, 6, and 12 months postoperatively are shown in Table 3, showing that preoperative BMI affects %EWL.

Table 3 Linear Regression Analysis of Preoperative BMI and %EWL at 1, 3, 6, and 12 Months Postoperatively

Figure 3 Correlaion analysis of %Excess Weight Loss and BMI. (A) Correlation between preoperative BMI and postoperative % Excess Weight Loss of patients at 1 month postoperatively; (B) Correlation between preoperative BMI and postoperative % Excess Weight Loss of patients at 3 months postoperatively; (C) Correlation between preoperative BMI and postoperative % Excess Weight Loss of patients at 6 months postoperatively; (D) Correlation between preoperative BMI and postoperative % Excess Weight Loss of patients at 12 months postoperatively.

The ROC curve results indicated that utilizing the patient’s preoperative BMI to predict the return to normal BMI at 12 months after LSG had some clinical application value, and the model’s accuracy was satisfactory (AUC=0.791, CI: 0710–0.872), refer to Table 4 and Figure 4.

Table 4 ROC Curve Analysis Results

Figure 4 The ROC curve for predicting patients reaching normal BMI at 12 months post-operatively by using preoperative BMI.

Comparison of Hypertension Relief in Three Groups

A total of 49 (36.57%) patients with obesity had preoperative combined hypertension and 31 (63.27%) patients achieved remission criteria at 12 months after surgery. As listed in Table 5, the number of hypertension remission in each group of Class I, II, and III obesity was 15 (71.43%), 9 (52.94%), and 7 (63.64%), with no statistically significant difference between groups (P>0.05, Table 5).

Table 5 Comparison of Remission Rates of Relevant Comorbidities in the Three Groups of Patients After Surgery

Comparison of Diabetes Remission in Three Groups

At 12 months postoperatively, 19 patients (76.00%) met the criteria for diabetes remission. As shown in Table 5, the number of patients with diabetes remission in each group for Class I, II, and III obesity was 6 (75.00%), 8 (72.73%) and 5 (83.33%), P>0.05.

Comparison of Remission of Dyslipidemia in Three Groups

As listed in Table 5, 32 patients (82.35%) reached remission of dyslipidemia at 12 months postoperatively. The number of patients with remission of dyslipidemia in each of the Class I, II, and III obesity groups [13 (68.42%) vs 11 (68.75%) vs 8 (66.67%)] with no statistically significant difference between groups (P>0.05).

Comparison of Quality of Life in the Three Groups After Surgery

The QOL scores for Class I, II, and III obesity at 12 months postoperatively were 1.30 (0.80, 1.80), 0.90 (0.70, 1.23), and 0.90 (0.70, 1.50) respectively, P<0.05, as listed in Table 6.

Table 6 Comparison of 12-Months Postoperative Complications and Quality of Life Scores Among the Three Groups of Patients

Comparison of Post-Operative Complications Between the Three Groups

Out of the total number of patients, 7 patients (5.22%) developed incision infection, 73 patients (54.48%) experienced postoperative nausea and vomiting (PONV), 18 patients (13.43%) developed gastroesophageal reflux disease (GERD), and 1 patient experienced gastric leakage. There was no notable variation in the frequency of complications among the groups (P>0.05), the data presented in Table 6.

Discussion

Obesity and its related health issues have emerged as a major public health concern in numerous countries worldwide.19 According to the 2018 data, approximately 51.2% of Chinese adults were categorized as overweight or obese, and it is estimated that this percentage could rise to 70.5% by the year 2030.20 LSG is an exceptionally effective method for treating obesity, and it is currently the most extensively used surgical procedure for bariatric surgery on a global scale.21 Previous studies22–25 have mostly focused on evaluating the efficacy as well as the safety of LSG, and there is a limited amount of research available on whether the effectiveness of LSG treatment varies among patients with different BMI obesity and whether LSG treatment is recommended for patients with low BMI. Various academics have contrasting opinions regarding the appropriateness of using LSG as a treatment for patients with low BMI obesity.

Based on our research, we propose that individuals with Class I obesity should receive more assertive recommendations for LSG treatment. In our 12 months study following surgery, we observed patients with different BMI showed varying degrees of postoperative weight loss. Specifically, we discovered that patients in Class I obesity experienced a significantly higher of %EWL at 1, 3, 6, and 12 months after surgery compared to the other two groups (P < 0.05). As the postoperative period increased, it was seen that the difference in the %EWL between the Class I patients with obesity and the other two groups became more pronounced. In contrast, %TWL presented significantly higher in patients with Class II and III obesity than in those with Class I (P < 0.05). Both %EWL and %TWL are indicators used to assess postoperative weight loss, but we think that %EWL provides a more comprehensive assessment of post-surgical weight modifications, due to the %EWL provides a more intuitive assessment of the loss of the excess weight of patients, while %TWL is closely associated with baseline weight. In a 3-year study by Park et al,26 postoperative %EWL was found to be higher in patients in the low BMI (30–35 kg/m2) group than in patients in the high BMI (>35 kg/m2) group. The timing of undergoing bariatric surgery is similar to that of cancer surgery. Just like how receiving surgical treatment in the early stages of cancer leads to more favorable outcomes, having surgery in the early stages of obesity increases the likelihood of achieving desired weight and improves overall outcomes for patients. According to the study conducted by Elnabil-Mortada et al,27 it has been found that LSG is a remarkably efficient method for managing obesity in individuals who are only mildly affected, and individuals with a higher BMI may not experience the same positive outcomes as those with a lower BMI. A study by Alqahtani AR et al28 found good postoperative outcomes in grade I patients with obesity underwent LSG. Various pieces of evidence indicate that LSG is highly effective in treating patients with Class I obesity.

Based on this foundation, we conducted a correlation analysis between patients’ preoperative BMI and their %EWL at 1, 3, 6, and 12 months after surgery. Our findings revealed a negative correlation between patients’ preoperative BMI and postoperative %EWL during the follow-up period. Furthermore, the results of our linear regression analysis confirmed that preoperative BMI can influence the patients’ postoperative %EWL. Patient’s preoperative BMI is closely associated with postoperative weight loss outcomes, which may be related to metabolic rate differences, hormonal regulation, dietary behaviors and lifestyles, gut microbiota, genetics, and genetic manifestations,29–31 but the exact mechanism remains to be further explored. Finally, the results of the ROC curves suggest that preoperative BMI has some clinical value in predicting whether patients can achieve a normal weight after surgery. In conclusion, patients with Class I obesity undergoing LSG can attain a satisfactory level of weight loss, and such patients are also more likely to experience “obesity remission”.

Moreover, aside from its efficacy in facilitating weight loss, the utilization of LSG as a therapeutic strategy for managing type 2 diabetes mellitus (T2DM) in individuals with obesity has garnered significant interest. Numerous studies have explored the use of LSG for managing T2DM, and the results have consistently shown that LSG is effective in treating this condition. The mechanisms of remission in T2DM can be categorised as weight-dependent and non-weight-dependent, but our study did not find significant differences in T2DM remission rates between the groups. The main pathogenic mechanisms of T2DM are thought to be a relative lack of insulin due to insulin resistance and reduced insulin secretion due to reduced function of pancreatic β cells. In our previous study, insulin resistance was found to be largely alleviated in patients treated with LSG,32 which may be the main cause of diabetes remission. Decreased levels of leptin and ghrelin in patients treated with LSG as well as a remission of chronic inflammation lead to a remission of insulin resistance.33–35

All individuals diagnosed with dyslipidemia experienced improvement following LSG treatment when compared to their preoperative condition. Furthermore, 68.09% of these patients achieved remission, and there was no notable variation in remission rates among different groups following the surgical procedure (P>0.05). This indicates that LSG is an effective treatment for dyslipidemia. Additionally, the preoperative BMI did not have an impact on the remission of dyslipidemia. A study conducted by Elnabil-Mortada et al27 similarly found no notable variation in the remission rate of dyslipidemia among patients with different BMI. Similarly, when we compared the rate of hypertension remission in the postoperative groups, we found that the remission rate was highest in Class III patients with obesity, but the difference between the groups was not statistically significant (P>0.05). At present, there is no clear mechanism for the remission of hypertension after LSG, and the mainstream view is that it is caused by the action of multiple pathways after LSG, such as sympathetic excitability changes, hormonal changes, adipokine changes, weight loss, etc.36 From the present study LSG is an effective measure for the treatment of obesity combined with hypertension. Based on the results of the QOL scores, we observed improvement in all patient groups’ QOL compared to their preoperative QOL. Upon comparing postoperative QOL scores within each group, we found that patients with Class I obesity exhibited significantly higher scores than those with Class II and Class III obesity. This may be closely related to the higher proportion of patients achieving “obesity remission” in the Class I category. No patient deaths occurred in this study, again demonstrating the safety of the LSG procedure.

This study still has some shortcomings and limitations. First, due to some irresistible factors, this study only analyzed the short-term efficacy of the patients after surgery and did not explore the influence of different BMI on the long-term efficacy of LSG after surgery. Secondly, this study retrospectively analyzed the efficacy of LSG in patients with different levels of obesity and did not compare the efficacy of different surgical modalities with LSG, so it was not possible to determine which surgical modality was more suitable for patients with different BMIs. Third, this study is a single-center, small-sample study. We will add to these in subsequent studies.

Conclusion

Individuals with obesity for varying BMI can experience favorable outcomes following LSG surgery. It is advisable to consider LSG treatment for patients with Class I obesity.

Ethics Approval Statement

The Ethics Committee at the First Affiliated Yijishan Hospital of Wannan Medical College approved this study. We obtained informed consent from all participants involved in this research.

Acknowledgments

Zilong Yue, Yan Jin, Hui Sha, and Qin Wu are co-first authors for this study. This study received support from the Key Teaching and Research Project of Anhui Provincial Department of Education (2021jyxm1623), Anhui Provincial Department of Education Outstanding Young Backbone Teachers of Colleges and Universities Overseas Visiting Training Project (gxgwfx2021040), Anhui Provincial Department of Education Provincial Quality Engineering Project (2022zyxwjxalk152), Scientific Research Fund for Key Projects at the Wannan Medical College (WK2023ZZD26) and Anhui Provincial Health Care Commission Scientific Research Project (AHWJ2023BAc10051). Many thanks for their valuable support.

Disclosure

The authors report no conflicts of interest in this work.

References

1. Cuciureanu M, Caratașu CC, Gabrielian L, et al. 360-degree perspectives on obesity. Medicina. 2023;59(6). doi:10.3390/medicina59061119

2. Liu FS, Wang S, Guo XS, Ye ZX, Zhang HY, Li Z. State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus. World J Diabetes. 2023;14(6):632–655. doi:10.4239/wjd.v14.i6.632

3. Afshin A, Forouzanfar MH, Reitsma MB, et al. Health effects of overweight and obesity in 195 countries over 25 years. N Engl J Med. 2017;377(1):13–27.

4. Van Hoang D, Inoue Y, Fukunaga A, et al. Metabolic syndrome and the risk of severe cancer events: a longitudinal study in Japanese workers. BMC Cancer. 2023;23(1):555. doi:10.1186/s12885-023-11026-7

5. Zhang H, Zhan Q, Dong F, et al. Associations of Chinese visceral adiposity index and new-onset stroke in middle-aged and older Chinese adults: an observational study. Lipids Health Dis. 2023;22(1):74. doi:10.1186/s12944-023-01843-x

6. Zhou CJ, Lin Y, Liu JY, Wang ZL, Chen XY, Zheng CG. Malnutrition and visceral obesity predicted adverse short-term and long-term outcomes in patients undergoing proctectomy for rectal cancer. BMC Cancer. 2023;23(1):576. doi:10.1186/s12885-023-11083-y

7. Sutandyo N, Hanafi AR, Jayusman AM, Kurniawati SA, Hanif MA. Overweight and obesity are associated with poorer survival among patients with advanced non-small cell lung cancer receiving platinum-based chemotherapy. Int J Gen Med. 2023;16:85–93. doi:10.2147/IJGM.S382577

8. Yang L, He Z, Gu X, Cheng H, Li L. Dose-response relationship between BMI and hyperuricemia. Int J Gen Med. 2021;14:8065–8071. doi:10.2147/IJGM.S341622

9. Angrisani L, Santonicola A, Iovino P, Ramos A, Shikora S, Kow L. Bariatric surgery survey 2018: similarities and disparities among the 5 IFSO chapters. Obes Surg. 2021;31(5):1937–1948. doi:10.1007/s11695-020-05207-7

10. Consensus Development Conference Panel. Gastrointestinal surgery for severe obesity. Consens Statement. 1991;9(1):1–20.

11. Eisenberg D, Shikora SA, Aarts E, et al. American Society of Metabolic and Bariatric Surgery (ASMBS) and international federation for the surgery of obesity and metabolic disorders (IFSO) indications for metabolic and bariatric surgery. Obes Surg. 2023;33(1):3–14. doi:10.1007/s11695-022-06332-1

12. Aisike G, Kuerbanjiang M, Muheyati D, Zaibibuli K, Lv MX, Han J. Correlation analysis of obesity phenotypes with leptin and adiponectin. Sci Rep. 2023;13(1):17718. doi:10.1038/s41598-023-43550-8

13. Osuna JA, Gómez-Pérez R, Arata-Bellabarba G, Villaroel V. Relationship between BMI, total testosterone, sex hormone-binding-globulin, leptin, insulin and insulin resistance in obese men. Arch Androl. 2006;52(5):355–361. doi:10.1080/01485010600692017

14. Edwards KL, Prendergast LA, Kalfas S, Sumithran P, Proietto J. Impact of starting BMI and degree of weight loss on changes in appetite-regulating hormones during diet-induced weight loss. Obesity. 2022;30(4):911–919. doi:10.1002/oby.23404

15. Kaplan U, Zohdy W, Gmora S, Hong D, Anvari M. What patient factors influence bariatric surgery outcomes? A multiple regression analysis of Ontario Bariatric Registry data. Can J Surg. 2022;65(1):E66–E72. doi:10.1503/cjs.018319

16. Carnethon MR, De Chavez PJ, Biggs ML, et al. Association of weight status with mortality in adults with incident diabetes. JAMA. 2012;308(6):581–590. doi:10.1001/jama.2012.9282

17. Brethauer SA, Kim J, El Chaar M, et al. Standardized outcomes reporting in metabolic and bariatric surgery. Surg Obes Relat Dis. 2015;11(3):489–506. doi:10.1016/j.soard.2015.02.003

18. Moorehead MK, Ardelt-Gattinger E, Lechner H, Oria HE. The validation of the moorehead-ardelt quality of life questionnaire II. Obes Surg. 2003;13(5):684–692. doi:10.1381/096089203322509237

19. Robert M, Espalieu P, Pelascini E, et al. Efficacy and safety of one anastomosis gastric bypass versus Roux-en-Y gastric bypass for obesity (YOMEGA): a multicentre, randomised, open-label, non-inferiority trial. Lancet. 2019;393(10178):1299–1309. doi:10.1016/S0140-6736(19)30475-1

20. Sun X, Yan AF, Shi Z, et al. Health consequences of obesity and projected future obesity health burden in China. Obesity. 2022;30(9):1724–1751. doi:10.1002/oby.23472

21. Salman MA, Elshazli M, Shaaban M, et al. Correlation between preoperative gastric volume and weight loss after laparoscopic sleeve gastrectomy. Int J Gen Med. 2021;14:8135–8140. doi:10.2147/IJGM.S335368

22. Arterburn D, Wellman R, Emiliano A, et al. Comparative effectiveness and safety of bariatric procedures for weight Loss: a PCORnet cohort study. Ann Intern Med. 2018;169(11):741–750. doi:10.7326/M17-2786

23. Murphy R, Plank LD, Clarke MG, et al. Effect of banded Roux-en-Y gastric bypass versus sleeve gastrectomy on diabetes remission at 5 years among patients with obesity and type 2 diabetes: a blinded randomized clinical trial. Diabetes Care. 2022;45(7):1503–1511. doi:10.2337/dc21-2498

24. Vital R, Navez J, Gunes S, et al. long-term outcomes 10 years after laparoscopic sleeve gastrectomy: a single center retrospective analysis. Obes Surg. 2023;33:2356–2360. doi:10.1007/s11695-023-06709-w

25. Peterli R, Wölnerhanssen BK, Peters T, et al. Effect of laparoscopic sleeve gastrectomy vs laparoscopic roux-en-y gastric bypass on weight loss in patients with morbid obesity: the SM-BOSS randomized clinical trial. JAMA. 2018;319(3):255–265. doi:10.1001/jama.2017.20897

26. Park JY, Kim YJ. Efficacy of laparoscopic sleeve gastrectomy in mildly obese patients with body mass Index of 30-35 kg/m(2). Obes Surg. 2015;25(8):1351–1357. doi:10.1007/s11695-015-1575-0

27. Elnabil-Mortada A, Elmaleh HM, Ackroyd R, Khaled RA. Effectiveness and safety of laparoscopic sleeve gastrectomy for weight loss in mild obesity: prospective cohort study with 3-year follow-up. Obes Surg. 2022;32(6):1918–1925. doi:10.1007/s11695-022-05958-5

28. Alqahtani AR, Alqahtani O, Amro N, et al. Long-term outcomes of laparoscopic sleeve gastrectomy in those with class I obesity: safety, efficacy, and quality of life. Surg Obes Relat Dis. 2023;19:1135–1141. doi:10.1016/j.soard.2023.03.005

29. Stanislawski MA, Dabelea D, Lange LA, Wagner BD, Lozupone CA. Gut microbiota phenotypes of obesity. NPJ Biofilms Microbiomes. 2019;5(1):18. doi:10.1038/s41522-019-0091-8

30. Joseph PV, Jaime-Lara RB, Wang Y, Xiang L, Henderson WA. Comprehensive and systematic analysis of gene expression patterns associated with body mass index. Sci Rep. 2019;9(1):7447. doi:10.1038/s41598-019-43881-5

31. Stefanov TS, Vekova AM, Kurktschiev DP, Temelkova-Kurktschiev TS. Relationship of physical activity and eating behaviour with obesity and type 2 diabetes mellitus: sofia Lifestyle (SLS) study. Folia Med. 2011;53(1):11–18. doi:10.2478/v10153-010-0022-1

32. Yue Z, Qian L, Jin Y, et al. Hyperinsulinemia influences the short-term efficiency of laparoscopic sleeve gastrectomy for patients with obesity and insulin resistance. Diabetes Metab Syndr Obes. 2023;16:1745–1753. doi:10.2147/DMSO.S411440

33. Kelly AS, Ryder JR, Marlatt KL, Rudser KD, Jenkins T, Inge TH. Changes in inflammation, oxidative stress and adipokines following bariatric surgery among adolescents with severe obesity. Int J Obes Lond. 2016;40(2):275–280. doi:10.1038/ijo.2015.174

34. Lo T, Haridas RS, Rudge E, et al. Early changes in immune cell count, metabolism, and function following sleeve gastrectomy: a prospective human study. J Clin Endocrinol Metab. 2022;107(2):e619–e630. doi:10.1210/clinem/dgab673

35. Lopez-Nava G, Negi A, Bautista-Castaño I, Rubio MA, Asokkumar R. Gut and metabolic hormones changes after endoscopic sleeve gastroplasty (ESG) Vs. laparoscopic sleeve gastrectomy (LSG). Obes Surg. 2020;30(7):2642–2651. doi:10.1007/s11695-020-04541-0

36. Graham C, Switzer N, Reso A, et al. Sleeve gastrectomy and hypertension: a systematic review of long-term outcomes. Surg Endosc. 2019;33(9):3001–3007. doi:10.1007/s00464-018-6566-5