Predictors of Weight Loss and Effectiveness of Roux-en-Y Gastric Bypass in the Morbidly Obese Hispano-American Population

Background  Co-morbidities and the metabolic response to intervention in morbid obesity have been reported to vary among different ethnic groups. We compared the rate of weight loss, effectiveness of gastric bypass surgery, and variables influencing success after gastric bypass in Hispanics compared to Caucasians. Methods  Morbidly obese adult (>18 years old) patients (body mass index [BMI] 40 or above) evaluated by our bariatric group from 2005 to 2006 who underwent Roux-en-Y gastric bypass (RYGBP) were studied. Every patient was evaluated for height, weight, BMI, percent body fat, fat mass, serum metabolic analysis (SMA) 12, lipid profile, complete blood count (CBC), iron, ferritin, Vitamins A, D, and B1, complete urinalysis and Fibrospect score II. Weight loss was evaluated at 1, 3, 6, and 12 months. Results  Seventy-five patients underwent successful open RYGBP with no mortality. Regardless of the significant difference in age and co-morbidities, the mean percentage of total weight loss after 1 year of follow-up was 32% for Hispanics and 30% for Caucasians with no significant difference (p > .5). When comparing the percentage of excess weight lost (% EWL) at 1, 3, 6, and 12 months, there was no significant difference between both groups. Using multiple regression analysis, we found that high-density lipoprotein (HDL) and systolic blood pressure (SBP) significantly predicted EWL at 12 months in Caucasians and Fibrospect predicted significantly EWL at 1 year. Conclusion  At 1 year after RYGBP, both ethnic groups lost ∼77–80% of their EWL and BMI. All Caucasians and 95.7% of Hispanics achieved successful weight loss (>50% EWL).     

The Impact of Preoperative Weight Loss in Patients Undergoing Laparoscopic Roux-en-Y Gastric Bypass

Background: Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is a widely performed bariatric operation. Preoperative factors that predict successful outcomes are currently being studied. The goal of this study was to determine if preoperative weight loss was associated with positive outcomes in patients undergoing LRYGBP. Methods: A retrospective analysis was performed of all patients undergoing LRYGBP at our institution between July 2002 (when a policy of preoperative weight loss was instituted) and August 2003. Outcome measures evaluated at 1 year postoperatively included percent excess weight loss (EWL) and correction of co-morbidities. Statistical analysis was performed by multiple linear regression. P<0.05 was considered significant. Results: The study included 90 subjects. Initial BMI ranged from 35.4 to 63.1 (mean 48.1). Preoperative weight loss ranged from 0 to 23.8% (mean 7.25). At 12 months, postoperative EWL ranged from 40.4% to 110.9 % (mean 74.4%). Preoperative loss of 1% of initial weight correlated with an increase of 1.8% of postoperative EWL at 1 year. In addition, initial BMI correlated negatively with EWL, so that an increase of 1 unit of BMI correlated with a decrease of 1.34% of EWL. Finally, preoperative weight loss of >5% correlated significantly with shorter operative times by 36 minutes. Preoperative weight loss did not correlate with postoperative complications or correction of co-morbidities. Conclusions: Preoperative weight loss resulted in higher postoperative weight loss at 1 year and in shorter operative times with LRYGBP. No differences in correction of co-morbidities or complication rates were found with preoperative weight loss in this study. Preoperative weight loss should be encouraged in patients undergoing bariatric surgery.     

Safety and Efficacy of Roux-en-Y Gastric Bypass to Treat Type 2 Diabetes Mellitus in Non-severely Obese Patients

The efficacy of Roux-en-Y gastric bypass (RYGB) to control type 2 diabetes mellitus (T2DM) has been demonstrated in morbidly obese patients. Surgical procedures primarily focused on T2DM control in patients with body mass index (BMI) < 35 kg/m² have shown to effectively induce remission of T2DM. However, only few reports have evaluated the safety and efficacy of RYGB in this group of patients. The aim of this study is to assess the safety and efficacy of RYGB in TD2M patients with BMI < 35 kg/m². All T2DM patients with BMI < 35 kg/m² and at least 12 months of follow-up who underwent laparoscopic RYGB were included. Safety of the procedure was evaluated according to mortality, need of reoperation/conversion, and complication rates. Metabolic parameters were evaluated at baseline and 6, 12, and 24 months after surgery. Thirty patients were included. Seventeen (56.6%) were women. Age, BMI, and duration of diabetes were 48 ± 9 years, 33.7 ± 1.2 kg/m², 4 ± 2.9 years, respectively. No mortality was observed. No conversion/reoperation was needed. Average length of stay was 3.2 ± 0.9 days. Early and late postoperative complications were observed in five (16.6%) and five (16.6%) patients, respectively. Twelve months after surgery, remission was observed in 25 of 30 patients (83.3%). After 2 years, remission was achieved in 13 of 20 patients (65%), and hemoglobin A1c decreased from 8.1 ± 1.8% to 5.9 ± 1.1% and homeostasis model assessment of insulin resistance from 5.7 ± 3.2 to 1.9 ± 0.8 after 12 months. RYGB is a safe and effective procedure to induce T2DM remission in otherwise not eligible patients for bariatric surgery. Evidence from prospective studies is needed to validate this approach.     

Energy Expenditure and Weight Regain in Patients Submitted to Roux-en-Y Gastric Bypass

Background  Although Roux-en-Y gastric bypass (RYGBP) is a highly effective treatment for clinically severe obesity, not all patients achieve desirable weight loss and maintenance. There is some evidence that weight loss can induce a disproportionate reduction in resting metabolic rate (RMR). This reduction in RMR can be related to fat-free mass (FFM) loss, as FFM is the greatest responsible for variations in energy expenditure at rest. Abnormally low basal metabolic rate may predispose surgical patients to weight regain. Method  Thirty-six individuals were divided into two groups: patients who have kept a healthy weight 2 years after surgery and patients who showed weight regain of at least 2 kg 2 years after the surgery. Selected patients have signed a consent form. Body mass index and excess weight loss were evaluated. RMR and body fat percentage were measured. FFM is a heterogeneous component that can be partitioned into muscle mass and no-muscle mass. The FFM was calculated as the result of subtracting total fat weight from total body weight in kilogram. We also wanted to know if the predictive formulas to assess RMR overestimate energy expenditure in these patients. Statistical tests were used to analyze the two groups. Results  We found out that the RMR of the weight regain group was statistically inferior to the mean of the healthy weight group—the difference between the two groups was about 260 kcal/day. We also found out that the predictive formulas overestimate the RMR in the weight regain group. Conclusion  This study suggests that a lower RMR may contribute to weight regain in patients who undergo RYGBP. It is important to ensure ways to elevate energy expenditure in the patient, such as increasing the percentage of fat-free mass in the body and the practice of physical activities.     

Mechanism of Roux-en-Y Gastric Bypass Treatment for Type 2 Diabetes in Rats

Objectives

Roux-en-Y gastric bypass (RYGB) is a novel therapy for diabetes. We aimed to explore the therapeutic mechanism of RYGB.

Methods

After RYGB, animal models were established, and gene expression profile of islets was assessed. Additionally, gastrointestinal hormones were measured using enzyme-linked immunosorbent assays. Ca²⁺ was studied using confocal microscopy and patch-clamp technique. The morphology of islets and beta cells was observed using optical microscopy and electron microscopy.

Results

RYGB was an effective treatment in diabetic rats. Expression profiling data showed that RYGB produced a new metabolic environment and that gene expression changed to adapt to the new environment. The differential expression of genes associated with hormones, Ca²⁺ and cellular proliferation was closely related to RYGB and diabetes metabolism. Furthermore, the data verified that RYGB led to changes in hormone level and enhanced Ca²⁺ concentration changes and Ca²⁺ channel activity. Morphological data showed that RYGB induced the proliferation of islets and improved the function of beta cells.

Conclusions

RYGB promoted a new metabolic environment while triggering changes to adapt to the new environment. These changes promoted the cellular proliferation of islets and improved the function of beta cells. The quantity of beta cells increased, and their quality improved, ultimately leading to insulin secretion enhancement.     

Weight Loss after Roux-en-Y Gastric Bypass in Obese Patients Heterozygous for MC4R Mutations

Background  

Heterozygous mutations in melanocortin-4 receptor (MC4R) are the most frequent genetic cause of obesity. Bariatric surgery is a successful treatment for severe obesity. The mechanisms of weight loss after bariatric surgery are not well understood.     

Roux-en-Y胃旁路术治疗2型糖尿病的研究进展

目的了解Roux-en-Y胃旁路术治疗2型糖尿病的概况,并总结其治疗2型糖尿病的效果及存在的问题。方法检索有关Roux-en-Y胃旁路术治疗2型糖尿病的文献并进行综述。结果Roux-en-Y胃旁路术对肥胖型2型糖尿病的治疗作用初步得到证实,但其治疗2型糖尿病的机制尚不明确,Roux袢及胆胰袢旷置长度没有统一的标准,术后远期效果不明确,其是否适用于非肥胖型2型糖尿病有待进一步研究。结论Roux-en-Y胃旁路术治疗2型糖尿病的机制复杂,相信随着基础与临床研究的进展、手术技术的改进、手术机制的阐明、远期效果的肯定,将有更多的2型糖尿病患者受益。     

Roux-en-Y胃转流术对2型糖尿病大鼠血清vaspin表达的影响

目的研究Roux-en-Y胃转流术(RYGB)对2型糖尿病(T2DM)大鼠的治疗作用,并探讨内脏脂肪组织产生的丝氨酸蛋白酶抑制剂(vaspin)在RYGB治疗T2DM机制中的可能作用。方法取造模成功的T2DM大鼠20只和周龄、性别相匹配的正常SD大鼠20只,用随机数字表法将其随机分为T2DM-RYGB组、T2DM-假手术组及RYGB组、假手术组,每组10只。分别于术前及术后第4和8周检测各组大鼠的空腹血糖(FPG)、血清胰岛素(INS)、血清vaspin水平及胰岛素抵抗指数(HOMA-IR),并分析血清vaspin水平与FPG、INS及HOMA-IR的相关性。结果手术前,T2DM-RYGB组与T2DM-假手术组比较以及RYGB组与假手术组比较,FPG水平、INS水平、vaspin水平及HOMA-IR差异均无统计学意义(P>0.05);而T2DM-RYGB组及T2DM-假手术组的FPG水平、INS水平、vaspin水平及HOMA-IR均分别明显高于RYGB组(P<0.05)及假手术组(P<0.05)。术后第4周,T2DM-RYGB组FPG水平、INS水平、vaspin水平及HOMA-IR较术前下降,除FPG水平(P<0.05)外,其余指标与术前比较差异均无统计学意义(P>0.05);术后第8周,FPG水平、INS水平、vaspin水平及HOMA-IR进一步下降,与术前比较差异均有统计学意义(P<0.05)。T2DM-假手术组、RYGB组及假手术组组内术前及术后第4周、第8周FPG水平、INS水平、vaspin水平及HOMA-IR比较,差异均无统计学意义(P>0.05)。手术前及手术后第4周、第8周T2DM-RYGB组与T2DM-假手术组血清vaspin水平与其对应血清INS水平、HOMA-IR均呈正相关(P<0.05)。结论 RYGB对T2DM大鼠具有一定的治疗作用,RYGB后vaspin表达水平降低,胰岛素敏感性改善,这可能是RYGB治疗T2DM的机制之一。     

Glycemic Control after Sleeve Gastrectomy and Roux-En-Y Gastric Bypass in Obese Subjects with Type 2 Diabetes Mellitus

Background

Roux-en-Y gastric bypass (LRYGB) has weight-independent effects on glycemia in obese type 2 diabetic patients, whereas sleeve gastrectomy (LSG) is less well characterized. This study aims to compare early weight-independent and later weight-dependent glycemic effects of LRYGB and LSG.

Methods

Eighteen LRYGB and 15 LSG patients were included in the study. Glucose, insulin, GLP-1, and GIP levels were monitored during a modified 30 g oral glucose tolerance test before surgery and 2 days, 3 weeks, and 12 months after surgery. Patients self-monitored glucose levels 2 weeks before and after surgery.

Results

Postoperative fasting blood glucose decreased similarly in both groups (LRYGB vs. SG; baseline—8.1?±?0.6 vs. 8.2?±?0.4 mmol/l, 2 days—7.8?±?0.5 vs. 7.4?±?0.3 mmol/l, 3 weeks—6.6?±?0.4 vs. 6.6?±?0.3 mmol/l, respectively, P <?0.01 vs. baseline for both groups; 12 months—6.6?±?0.4 vs. 5.9?±?0.4, respectively, P <?0.05 for LRYGB and P <?0.001 for LSG vs. baseline, P =?ns between the groups at all times). LSG, but not LRYGB, showed increased peak insulin levels 2 days postoperatively (mean?±?SEM; LSG +?58?±?14%, P <?0.01; LRYGB ??8?±?17%, P =?ns). GLP-1 levels increased similarly at 2 days, but were higher in LRYGB at 3 weeks (AUC; 7525?±?1258 vs. 4779?±?712 pmol?×?min, respectively, P <?0.05). GIP levels did not differ. Body mass index (BMI) decreased more after LRYGB than LSG (??10.1?±?0.9 vs. ??7.9?±?0.5 kg/m², respectively, P <?0.05).

Conclusion

LRYGB and LSG show very similar effects on glycemic control, despite lower GLP-1 levels and inferior BMI decrease after LSG.

     

Glycemic Control and Insulin Treatment Alter Fracture Risk in Older Men With Type 2 Diabetes Mellitus

Diabetes mellitus among older men has been associated with increased bone mineral density but paradoxically increased fracture risk. Given the interactions among medication treatment, glycemic control, and diabetes-associated comorbidities, the relative effects of each factor remains unclear. This retrospective study includes 652,901 male veterans aged ≥65 years with diabetes and baseline hemoglobin A1c (HbA1c) value. All subjects received primary care in the Veterans Health Administration (VHA) from 2000 to 2010. Administrative data included ICD9 diagnoses and pharmacy records and was linked to Medicare fee-for-service data. Hazard ratios (HR) for any clinical fracture and hip fracture were calculated using competing risk hazards models, adjusted for fracture risk factors including age, race/ethnicity, body mass index (BMI), alcohol and tobacco use, rheumatoid arthritis, corticosteroid use, as well as diabetes-related comorbidities including cardiovascular disease, chronic kidney disease, and peripheral neuropathy. HbA1c <6.5% was associated with a higher risk of any clinical fracture (HR = 1.08, 95% confidence interval [CI] 1.06–1.11) compared with the reference HbA1c of 7.5% to 8.5%. Fracture risk was not increased among those with A1c ≥8.5%, nor among those with A1c 6.5% to 7.5%. Use of insulin was independently associated with greater risk of fracture (HR = 1.10, 95% CI 1.07–1.12). There was a significant interaction between insulin use and HbA1c level, (p < 0.001), such that those using insulin with HbA1c <6.5% had HR = 1.23 and those with HbA1c 6.5% to 7.5% had HR = 1.15. Metformin use was associated with decreased fracture risk (HR = 0.88, 95% CI 0.87–0.90). We conclude that among older men with diabetes, those with HbA1c lower than 6.5% are at increased risk for any clinical and hip fracture. Insulin use is associated with higher fracture risk, especially among those with tight glycemic control. Our findings demonstrate the importance of the treatment regimen and avoiding hypoglycemia for fracture prevention in older men with diabetes. © 2019 American Society for Bone and Mineral Research.     

Total Weight Loss as the Outcome Measure of Choice After Roux-en-Y Gastric Bypass

Background

Currently, there is no agreement on the best method to describe weight loss (WL) after bariatric surgery. The aim of this study is to evaluate short-term outcomes using percent of total body weight loss (%TWL).

Methods

A single-institution retrospective study of 2420 patients undergoing Roux-en-Y gastric bypass (RYGB) was performed. Suboptimal WL was defined as %TWL?<?20 % at 12 months.

Results

Mean preoperative BMI was 46.8?±?7.8 kg/m². One year after surgery, patients lost an average 14.1 kg/m² units of body mass index (BMI), 30.0?±?8.5 %TWL, and 68.5?±?22.9 %EWL. At 6 and 12 months after RYGB, mean BMI and percent excess WL (%EWL) significantly improved for all baseline BMI groups (p?<?0.01, BMI; p?=?0.01, %EWL), whereas mean %TWL was not significantly different among baseline BMI groups (p?=?0.9). The regression analysis between each metric outcome and preoperative BMI demonstrated that preoperative BMI did not significantly correlate with %TWL at 1 year (r?=?0.04, p?=?0.3). On the contrary, preoperative BMI was strongly but negatively associated with the %EWL (r?=??0.52, p?<?0.01) and positively associated with the BMI units lost at 1 year (r?=?0.56, p?<?0.01). In total, 11.3 % of subjects achieved <20 %TWL at 12 months and were considered as suboptimal WL patients.

Conclusion

The results of our study confirm that %TWL should be the metric of choice when reporting WL because it is less influenced by preoperative BMI. Eleven percent of patients failed to achieve successful WL during the in the first year after RYGB based on our definition.

     

Preoperative Fasting C-Peptide Predicts Type 2 Diabetes Mellitus Remission in Low-BMI Chinese Patients After Roux-en-Y Gastric Bypass

Objective

This study investigated the role of preoperative fasting C-peptide (FCP) levels in predicting diabetic outcomes in low-BMI Chinese patients following Roux-en-Y gastric bypass (RYGB) by comparing the metabolic outcomes of patients with FCP >?1 ng/ml versus FCP ≤?1 ng/ml.

Methods

The study sample included 78 type 2 diabetes mellitus patients with an average BMI <?30 kg/m² at baseline. Patients’ parameters were analyzed before and after surgery, with a 2-year follow-up. A univariate logistic regression analysis and multivariate analysis of variance between the remission and improvement group were performed to determine factors that were associated with type 2 diabetes remission after RYGB. Linear correlation analyses between FCP and metabolic parameters were performed. Patients were divided into two groups: FCP >?1 ng/ml and FCP ≤?1 ng/ml, with measured parameters compared between the groups.

Results

Patients’ fasting plasma glucose, 2-h postprandial plasma glucose, FCP, and HbA1c improved significantly after surgery (p?<?0.05). Factors associated with type 2 diabetes remission were BMI, 2hINS, and FCP at the univariate logistic regression analysis (p <?0.05). Multivariate logistic regression analysis was performed then showed the results were more related to FCP (OR = 2.39). FCP showed a significant linear correlation with fasting insulin and BMI (p?<?0.05). There was a significant difference in remission rate between the FCP >?1 ng/ml and FCP ≤?1 ng/ml groups (p?=?0.01). The parameters of patients with FCP >?1 ng/ml, including BMI, plasma glucose, HbA1c, and plasma insulin, decreased markedly after surgery (p?<?0.05).

Conclusion

FCP level is a significant predictor of diabetes outcomes after RYGB in low-BMI Chinese patients. An FCP level of 1 ng/ml may be a useful threshold for predicting surgical prognosis, with FCP >?1 ng/ml predicting better clinical outcomes following RYGB.

     

Greater Weight Loss with the Omega Loop Bypass Compared to the Roux-en-Y Gastric Bypass: a Comparative Study

Background

Despite similar initial results on weight loss and metabolic control, with a better feasibility than the Roux-en-Y gastric bypass (RYGBP), the omega loop bypass (OLB) remains controversial. The aim of this study was to compare the short-term outcomes of the laparoscopic OLB versus the RYGBP in terms of weight loss, metabolic control, and safety.

Methods

Two groups of consecutive patients who underwent laparoscopic gastric bypass surgery were selected: 20 OLB patients and 61 RYGBP patients. Patients were matched for age, gender, and initial body mass index (BMI). Data concerning weight loss, metabolic outcomes, and complications were collected prospectively.

Results

Mean duration of the surgical procedure was shorter in the OLB group (105 vs 152 min in the RYGBP group; p?<?0.001). Mean excess BMI loss percent (EBL%) at 6 months and at 1 year was greater in the OLB group (76.3 vs 60.0 %, p?=?0.001, and 89.0 vs 71.0 %, p?=?0.002, respectively). After adjustment for age, sex, initial BMI, and history of previous bariatric surgery, the OLB procedure was still associated with a significantly greater 1-year EBL%. Diabetes improvement at 6 months was similar between both groups. The early and late complication rates were not statistically different. There were three anastomotic ulcers in the OLB group, in smokers, over 60 years old, who were not taking proton pump inhibitor medication.

Conclusions

In this short-term study, we observed a greater weight loss with OLB and similar efficiency on metabolic control compared to RYGBP. Long-term evaluation is necessary to confirm these outcomes.     

Relative Contribution of Modifiable Versus Non-Modifiable Factors as Predictors of Racial Variance in Roux-en-Y Gastric Bypass Weight Loss Outcomes

African-Americans have been shown to have poorer weight loss outcomes after bariatric surgery, and many reasons for such outcomes have been postulated, including metabolic and genetic differences, socioeconomic factors, and differences in culture. African-Americans have also been noted to have differences from the majority population in other psychosocial correlates to weight loss outcomes. However, the relative contribution of targetable factors in relation to non-modifiable factors to such outcomes remains unclear. African-American and Caucasian patients who had received a Roux-en-Y gastric bypass and returned for a 12-month follow up appointment (n?=?415) were selected for retrospective analysis. A stepwise hierarchical regression of 12 month percent excess weight loss (% EWL) was conducted that included race after controlling for psychosocial and demographic factors previously linked to postsurgical outcomes. These variables were then compared between racial groups using independent t tests and chi-square analyses. Race remained a significant predictor of % EWL after controlling for pertinent psychosocial and demographic variables. Age and preoperative BMI were significant negative predictors, whereas presurgical BMI loss and Caucasian race were positive (p?<?0.05). Percentage of follow-up appointment attendance was borderline significant. No significant racial differences were noted in these variables. Non-modifiable factors inherent to race such as metabolism play small but significant roles in the postoperative weight loss in African-American patients. Further research is needed to better elucidate the roles of targetable factors in outcomes, particularly adherence and pay status as their evaluation in this study was limited.     

Vagal Innervation of Intestine Contributes to Weight Loss After Roux-en-Y Gastric Bypass Surgery in Rats

Background

It is conceivable that overstimulation of chemo- and mechano-sensors in the Roux and common limbs by uncontrolled influx of undigested nutrients after Roux-en-Y gastric bypass surgery (RYGB) could lead to exaggerated satiety signaling via vagal afferents and contribute to body weight loss. Because previous clinical and preclinical studies using vagotomy came to different conclusions, the aim was to examine the effects of selective and histologically verified celiac branch vagotomy on reduced food intake and body weight loss induced by RYGB.

Methods

Male Sprague–Dawley rats underwent either RYGB + celiac branch vagotomy (RYGB/VgX, n?=?15), RYGB + sham celiac branch vagotomy (RYGB/Sham VgX; n?=?6), Sham RYGB + celiac branch vagotomy (Sham/VgX; n?=?6), or sham RYGB + sham celiac branch vagotomy (Sham/Sham; n?=?6), and body weight, body composition, and food choice were monitored for 3 months after intervention.

Results

In rats with RYGB, histologically confirmed celiac branch vagotomy significantly moderated weight loss during the first 40 days after surgery, compared to either sham or failed vagotomy (P?P?Conclusions The results suggest that signals carried by vagal afferents from the mid and lower intestines contribute to the early RYGB-induced body weight loss and reduction of food intake.     

A Review of Weight Loss Following Roux-en-Y Gastric Bypass vs Restrictive Bariatric Surgery: Impact on Adiponectin and Insulin

Background  

Bariatric surgery is a common procedure often used to ameliorate comorbidities associated with obesity, including type 2 diabetes. Substantial weight loss leads to alterations in inflammation and insulin sensitivity as well as numerous metabolic and physiologic pathways. Several inflammatory markers have been evaluated, yet adiponectin, an anti-inflammatory adipokine, has not been fully investigated. Adiponectin may play a key role as a mediator between obesity and inflammation, as lower blood levels are more commonly associated with obesity and type 2 diabetes and because adiponectin lessens insulin resistance. This review evaluates outcome variables from patients who underwent Roux-en-Y gastric bypass (RYGB) or restrictive bariatric surgery to compare and contrast any differential surgical impacts on weight loss, adiponectin, and insulin.     

Predictors of Excess Weight Loss in Obese Patients After Gastric Bypass: a 60-Month Follow-up

Background

The objective of this study was to analyze the factors associated with change in body mass index (BMI) and with percentage of excess weight loss (%EWL) in patients undergoing Roux-en-Y gastric bypass (RYGB). The following factors were analyzed: sex, age, surgical access (laparotomy vs. laparoscopy), preoperative BMI, waist circumference (WC), type 2 diabetes mellitus (T2DM), high blood pressure, and dyslipidemia.

Methods

Retrospective cohort study using a convenience sample of 2070 patients of both sexes, aged 18 to 65 years, undergoing RYGB between 2000 and 2013. The outcomes of interest were BMI and %EWL at 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months after RYGB.

Results

After 36, 48, and 60 months, approximately 50 % of patients had BMI >30 kg/m². As for %EWL, 60-month results were poor for 17 % of patients (%EWL <50 %), good for 40 % of patients (%EWL 50–75 %), very good for 24 % of patients (%EWL from >75–90 %), and excellent for 19 % of patients (%EWL >90 %). The four most significant predictors of BMI change 60 months after RYGB (in descending order of magnitude) were preoperative BMI, preoperative WC, surgical access, and age; and of %EWL, surgical access, preoperative BMI, preoperative WC, and age.

Conclusions

After 60 months of follow-up, the most relevant predictors of weight loss after RYGB were lower preoperative BMI and WC, videolaparoscopy as surgical access, and younger age. Further studies must be carried out to elucidate the impact of these factors on RYGB outcomes.

     

Short-term Changes in Insulin Resistance following Weight Loss Surgery for Morbid Obesity: Laparoscopic Adjustable Gastric Banding versus Laparoscopic Roux-en-Y Gastric Bypass

Background: Laparoscopic adjustable gastric banding (LAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGBP) both effectively treat the insulin resistance associated with type 2 diabetes mellitus (T2DM). Restriction of caloric consumption, alterations in the entero-insular axis or weight loss may contribute to lowering insulin resistance after these procedures. The relative importance of these mechanisms, however, following LAGB and LRYGBP remain unclear. The aim of this study was to compare directly the short-term changes in insulin resistance following LAGB and LRYGBP in similar populations of patients. Methods: Patient preference determined operation type. The Homeostasis Model Assessment for Insulin Resistance (HOMA IR) was used to measure insulin resistance. Preoperative values were compared to postoperative levels obtained within 90 days of surgery. Significant differences between groups were tested by ANOVA. Results: There were no significant preoperative differences between groups. The 56 LAGB patients had a mean age of 42.5 years (25.7-63), BMI of 45.5 kg/m² (35-66) and preoperative HOMA IR of 4.1 (1.4-39.2). 75% of LAGB patients were female and 43% had T2DM. The 61 LRYGBP patients had a median age of 39.9 years (22.1-64.3), BMI of 45.0 kg/m² (36-62), and preoperative HOMA IR of 5.0 (0.6-56.5). 79% of LRYGBP patients were women and 44.3% had T2DM. Median follow-up for LAGB patients was 45 days (18-90) and for LRYGBP patients 46 days (8-88 days). LAGB patients had a median of 14.8% excess weight loss (6.9%-37.0%) and LRYGB patients 24.2% (9.8%-51.4%). Postoperative HOMA IR was significantly less after LRYGBP, 2.2 (0.7-12.2), than LAGB, 2.6 (0.8-29.6), although change in HOMA IR was not significantly different. Change in HOMA IR for both groups did not vary with length of follow-up or weight loss but correlated best with preoperative HOMA IR (LAGB r=0.8264; LRYGBP r=0.9711). Conclusions: Both LAGB and LRYGBP significantly improved insulin resistance during the first 3 months following surgery. Both operations generated similar changes in HOMA IR, although postoperative HOMA IR levels were significantly lower after LRYGBP. These findings suggest that caloric restriction plays a significant role in improving insulin resistance after both LAGB and LRYGBP.