Definition, Mechanisms and Predictors of Weight Loss Failure After Bariatric Surgery

Bariatric nutrition and evaluation of the metabolic surgical patient: Update to the 2022 Obesity Medicine Association (OMA) bariatric surgery, gastrointestinal hormones, and the microbiome clinical practice statement (CPS)

Background

In 2022, the Obesity Medicine Association (OMA) published a Clinical Practice Statement (CPS) which provided an overview of bariatric surgery and related procedures, a discussion on gastrointestinal hormones and a review of the microbiome as it relates to patients with obesity. This update to the 2022 OMA CPS provides a focus on nutrition as it relates to the adult bariatric surgery patient, incorporating a detailed discussion on how to conduct a bariatric nutrition assessment and manage patients seeking metabolic and bariatric surgery (MBS) and postoperative nutrition care. In particular, the section on macronutrients, micronutrients, and bariatric surgery has been updated, highlighting practical approaches to nutrient deficiencies typically encountered in the bariatric surgery patient. Also included is a section on how to envision and develop an interdisciplinary team of medical providers with evidence-based nutrition knowledge and consistent information that improves the quality of nutrition care provided to MBS patients. This CPS adds to the series of OMA CPSs meant to provide guidance to clinicians in their care of patients with obesity.

Methods

The foundation of this paper is supported by scientific evidence in the medical literature and expert opinion derived from several bariatric nutrition resources, as well as from the 2022 OMA CPS focused on bariatric surgery.

Results

This OMA Clinical Practice Statement provides an overview of the current bariatric nutrition clinical guidelines and nutrition tools adapted for clinicians who may not have access to an MBS team or a registered dietitian knowledgeable about bariatric nutrition.

Conclusions

This evidence-based review of the literature includes an overview of current bariatric nutrition recommendations. It is intended to provide clinicians with more advanced knowledge and skills in nutrition assessment and management of the preoperative and post-surgical MBS patients. This CPS also addresses macronutrient and micronutrient deficiencies common in MBS patients, and treatment recommendations designed to help the clinician with clinical decision making.

Long-Term Outcome of One-Anastomosis Gastric Bypass: 10-Year Follow-Up of a Single Institution Series

BACKGROUND

This study aims to evaluate the long-term efficacy, safety, nutritional status, and resolution of obesity complications of patients following one-anastomosis gastric bypass (OAGB).

METHODS

A retrospective observational study of patients who underwent OAGB in our center between January 2011 and December 2013 was performed.

RESULTS

During the study period, 152 patients underwent OAGB procedure in our center. Among them, 26 patients were lost to follow up and therefore were excluded from the data analysis. A total of 126 patients completed long-term follow-up of 10 years. The mean age of patients at baseline was 41 ± 12.5 years (range 20-68). At 10-year follow-up, mean excess weight loss (EWL) was 68.9 ± 22.8%. Mean BMI was 29.7 ± 12.9 kg/m2, representing an overall BMI reduction of 10.6 kg/m2. At 10-year follow-up among the 126 patients, 80% had resolution in DM, 71% had resolution in HTN, and 85% had resolution in OSA. There were no instances of severe malnutrition in the 126 patients in our study.

CONCLUSIONS

OAGB is an effective choice of bariatric/metabolic surgery for patients with higher BMI which provides good weight loss in terms of % TWL and % EWL without significant recurrent weight gain or inadequate weight loss with negligible nutritional deficiencies.

Assessment of weight change patterns following Roux en Y gastric bypass, one anastomosis gastric bypass and sleeve gastrectomy using change-point analysis

We aimed to assess the weight loss trend following Roux en Y Gastric Bypass (RYGB), One Anastomosis Gastric Bypass (OAGB), and Sleeve Gastrectomy (SG), utilizing a change-point analysis. A retrospective cohort study was conducted on 8640 patients, from 2009 to 2023. The follow-up period extended to 7 years, with a median follow-up of 3 years (interquartile range: 1.4-5). Following metabolic bariatric surgery, four weight loss phases (three change points) were observed. The primary, secondary, and tertiary phases, transitioned at 12.64-13.73 days, 4.2-4.8 months, and 11.3-13.1 months post-operation, respectively, varying based on the type of procedure. The weight loss rate decreased following each phase and plateaued after the tertiary phase. The nadir weight was achieved 11.3-13.1 months post-procedure. There was no significant difference in the %TWL between males and females, however, males achieved their nadir weight significantly earlier. Half of the maximum %TWL was achieved within the first 5 months, with the greatest reduction rate in the first 2 weeks. Our findings inform healthcare providers of the optimal timing for maximum weight loss following each surgical method and underscore the importance of close patient monitoring in the early postoperative period.

Prediction Model for Chronological Weight Loss After Bariatric Surgery in Korean Patients

Purpose

This study aimed to develop a predictive model for monitoring chronological weight loss during the early postoperative period following bariatric surgery in Korean patients with morbid obesity.

Materials and Methods

The baseline characteristics and postoperative weight loss outcomes were collected for up to 24 months after surgery in patients who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). The factors influencing weight loss outcomes were analyzed, and longitudinal percentile charts were plotted using quantile regression models adjusted for the identified independent factors.

Results

The analysis included 491 and 274 patients who underwent SG and RYGB, respectively, of whom 225 (29.4%) were men. A positive association was found between the maximum percentage of total weight loss (%TWL) and female sex, body mass index (BMI) ≥40, and age <40 years. Among patients who reached nadir BMI or had at least 12 months of follow-up data (n=304), 7.6% exhibited inadequate weight loss (TWL <20%). The predictors of insufficient weight loss were older age (>40 years), male sex, and psychological problems. Centile charts were generated for the entire cohort, incorporating age, sex, and the type of procedure as covariates.

Conclusion

The percentile charts proposed in the present study can assist surgeons and healthcare providers in gauging patients' progress toward their weight loss goals and determining the timing of adjunctive intervention in poor responders during early postoperative follow-up.

Utilization of Anti-obesity Medications After Bariatric Surgery: Analysis of a Large National Database

PURPOSE

A significant proportion of patients experience insufficient weight loss or weight regain after bariatric surgery. There is a paucity of literature describing anti-obesity medication (AOM) use following bariatric surgery. We sought to identify prevalence and trends of AOM use following bariatric surgery.

MATERIALS AND METHODS

We utilized the IBM Explorys® database to identify all adults with prior bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy). Those prescribed AOMs (semaglutide, liraglutide, topiramate, phentermine/topiramate, naltrexone/bupropion, orlistat) within 5 years of surgery were further identified. Data was analyzed to characterize AOM utilization among different age, demographic, and comorbid populations.

RESULTS

A total of 59,160 adults with prior bariatric surgery were included. Among AOMs studies, prevalence of use was highest for topiramate (8%), followed by liraglutide (2.9%), phentermine/topiramate (1.03%), naltrexone/bupropion (0.95%) semaglutide (0.52%), and orlistat (0.17%). Age distribution varied, with the highest utilization among those age 35-39 years for topiramate, 40-44 years for phentermine/topiramate and naltrexone/bupropion, 45-49 years for semaglutide, and 65-69 years for liraglutide and orlistat. African American race was associated with higher utilization across all AOMs. Among comorbidities, hypertension, hyperlipidemia, and diabetes mellitus were most associated with AOM use.

CONCLUSION

Despite a relatively high incidence of weight regain, AOMs are underutilized following bariatric surgery. It is imperative that barriers to their use be addressed and that AOMs be considered earlier and more frequently in patients with insufficient weight loss or weight regain after bariatric surgery.

Plasma SHBG Levels as an Early Predictor of Response to Bariatric Surgery

BACKGROUND

Obesity is a growing global health problem, and currently, bariatric surgery (BS) is the best solution in terms of sustained total weight loss (TWL). However, a significant number of patients present weight regain (WR) in time. There is a lack of biomarkers predicting the response to BS and WR during the follow-up. Plasma SHBG levels, which are low in obesity, increase 1 month after BS but there is no data of plasma SHBG levels at long term. We performed the present study aimed at exploring the SHBG role in predicting TWL and WR after BS.

METHODS

Prospective study including 62 patients with obesity undergoing BS. Anthropometric and biochemical variables, including SHBG were analyzed at baseline, 1, 6, 12, and 24 months; TWL ≥ 25% was considered as good BS response.

RESULTS

Weight loss nadir was achieved at 12 months post-BS where maximum SHBG increase was reached. Greater than or equal to 25% TWL patients presented significantly higher SHBG increases at the first and sixth months of follow-up with respect to baseline (100% and 150% respectively, p = 0.025), than < 25% TWL patients (40% and 50% respectively, p = 0.03). Also, these presented 6.6% WR after 24 months. The first month SHBG increase predicted BS response at 24 months (OR = 2.71; 95%CI = [1.11-6.60]; p = 0.028) and TWL in the 12th month (r = 0.330, p = 0.012) and the WR in the 24th (r =  - 0.301, p = 0.028).

CONCLUSIONS

Our results showed for the first time that increase in plasma SHBG levels within the first month after BS is a good predictor of TWL and WR response after 2 years.

Positive Program Evaluation and Health Maintenance among Post-Metabolic and Bariatric Surgery Patients Following a 6-Week Pilot Program

PURPOSE

Despite lifestyle changes and medication therapies, weight loss is difficult to maintain. Metabolic and bariatric surgery (MBS) is an effective route for significant weight reduction. However, post-operation there are limited opportunities to support weight loss maintenance. The following study aimed to pilot test a 6-week, 6-session nutrition and support program for post-MBS surgery patients.

MATERIALS AND METHODS

A 6-week post-MBS pilot nutrition and support program was developed to test feasibility and acceptability. Participants completed a baseline survey that included demographics, weight changes, success post-surgery, and self-efficacy of leading a healthy lifestyle. Weight change, percent total weight loss, self-efficacy, and program evaluation measures were assessed.

RESULTS

Participants (n = 18) were recruited from a local MBS clinic, predominately female (88.9%), non-Hispanic white (94.4%), received sleeve gastrectomy surgery (100%), and were 2-3 years post-operation (44.4%). Eight of the 18 participants attended the in-person sessions, serving as the intervention group. Both weight loss over and behavioral variables remained stable for both groups across the 6 weeks with no significant differences from pre to post program (p > 0.05). For program evaluation, intervention participants "agreed" or "strongly agreed" with 10 of 11 program satisfaction measures.

CONCLUSION

Following the program, weight loss was maintained among both intervention and control groups. Intervention feedback indicated that the program's approach to provide nutrition education and support was successful and acceptable. Future enhancement of the intervention should include a broader multidisciplinary approach, longer intervention period, and intentional recruitment of participants with a weight regain.

Correlation Between Gastrojejunal Anastomosis Diameter, Distensibility Index, and Weight Regain After Roux-en-Y Gastric Bypass

INTRODUCTION

Gastrojejunal anastomosis (GJA) dilation is an independent predictor of weight regain (WR) after Roux-en-Y gastric bypass (RYGB). However, the role of planimetric measurements in this context remains unknown.

METHODS

This is a retrospective cohort study including adult RYGB patients who underwent a diagnostic endoscopy with Endoflip assessment of the GJA. We excluded patients in the early postoperative period and those with abnormal endoscopic findings (marginal ulcers and gastro-gastric fistulas).

RESULTS

Thirty-four patients were initially included. Endoscopic GJA diameter had a moderate positive correlation with WR (r=+0.438, p=0.011). However, after excluding the 7 patients with GJA> 30 mm, there was no significant correlation. There was a moderate agreement between the EndoFLIP-GJA diameter at 60mL and endoscopic diameter (ICC=0.576, p=0.049). The distensibility index (DI) showed a consistent moderate negative correlation with WR. Considering the maximum DI at 40 ml, we found a cutoff of DI = 7 mm2/mmHg that split the sample in two significantly different populations in terms of WR (67.4% vs. 43.2%, p=0.04).

CONCLUSION

Visual estimation of the GJA diameter correlates with EndoFLIP at 60mL. In the subset of patients with GJA ≤ 30 mm, more distensible GJAs are associated with lower rates of WR. Larger studies are needed to confirm this correlation and to validate its utility for clinical management.

Long-Term Outcomes of Sleeve Gastrectomy: Weight Recurrence and Surgical Non-responders

INTRODUCTION

Sleeve gastrectomy (SG) is an effective procedure with remarkable weight loss and low complication rates. However, up to 30% of cases require revisional surgery in non-responders or patients who experience weight recurrence. We aim to report the rate of weight recurrence/non-responders (WR/NR) in patients who underwent SG and had more than 5 years of follow-up.

METHODS

We performed a multicenter retrospective study of patients who underwent initial SG from 2008 to 2017. Patient demographics and weight loss outcomes up to 12 years after SG were collected. Surgical non-responders were defined as 20% weight regain compared to maximum weight loss. A chi-square test for categorical variables and a two-sample t-test for continuous variables were used. Data are summarized as mean ± standard deviation.

RESULTS

From a total of 1263 patients, we included 339 patients (78% female, age 47.3 ± 11.2 years; baseline weight 125.8 ± 27.6 kg) with at least 5 years of follow-up (mean follow-up of 7.1 ± 1.8 years) (Table 1). Surgical non-response was demonstrated in 15.9% of patients (n=54) and 64.0% (n=217) had weight recurrence after SG (Fig. 1). There was a statistically significant difference in history of hypertension (p=0.046) and diabetes (p=0.032) as well as %TBWL at 1 year (p=0.005) and at longest follow-up (p<0.001) between patients who experienced WR/NR and those who did not.

CONCLUSIONS

Only 20% of patients who underwent SG and followed up for more than 5 years were able to maintain appropriate weight loss.