Centile Charts for Monitoring of Weight Loss Trajectories After Bariatric Surgery in Asian Patients

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.

Collaborative Prescribing Practice in Managing Patients Post-Bariatric Surgery in a Tertiary Centre in Singapore

Background: A collaborative prescribing (CP) practice model, established by the endocrinologists, pharmacists, and advanced practice nurses, aims to provide for the postoperative monitoring and medical and nutritional management of stable patients after bariatric surgery. Method: Under the CP agreement, endocrinologists refer patients who have undergone bariatric surgery with stable medical conditions to CP practitioners, comprising senior pharmacists and advanced practice nurses. CP practitioners review the patient's weight loss progress, blood test results and vitals, the sufficiency of micronutrient repletion, adherence to supplements and medications, and chronic disease control. CP practitioners can prescribe and adjust the medications and supplements, in accordance with a clinical evaluation and standard guidance. Patients who require immediate attention due to complications or red flags are referred to the primary endocrinologist for further management. Results: From 5 May 2020 to 30 September 2023, CP practitioners provided 672 consultations. At least 68% and 80% of patients achieved appropriate weight loss post-surgery during the acute and maintenance phases, respectively. Less than 10% of the patients presented with anaemia and iron deficiency, and vitamin B12, folate and vitamin D deficiency. More than 80% of patients achieved a HbA1c of less than 7%. Conclusions: The CP practice framework provides a sustainable and viable model to facilitate optimal outcomes after bariatric surgery.

Weight Reduction Percentile Charts: 2-Year Follow-up Results of OAGB and RYGB Post Bariatric Surgery

PURPOSE

Using a single percentile chart provides us with high standards for the evaluation and accurate investigation of sufficient weight loss after bariatric surgery, counseling, and treating patients in an evidence-based way. Creating percentile charts of weight loss for gastric bypass is the aim of this study.

MATERIALS AND METHODS

This retrospective study was based on data from patients who underwent RYGB or OAGB from February 2008 to February 2020. The lambda-mu-sigma (LMS) method was used to estimate the reduction in body mass index (BMI) and six other metrics measured throughout post-operative follow-up. Percentile charts for various metrics have been presented for the first 2 years' post-surgery. We applied a bootstrap sampling method to evaluate percentile validity.

RESULTS

We recruited 2579 and 1943 patients who underwent OAGB (75% female) and RYGB (84% female) and were between the ages of 18 and 70 years. The preoperative BMI of patients in the OAGB group was higher than in the RYGB group. Concerning RYGB weight reduction results, the maximum percentage of excess weight loss (%EWL) occurs 18 months after surgery and is steady at 24 months. Far above 50%, EWL is achieved after 6 months. OAGB weight loss follows the same trend as RYGB; at 6 months, the %EWL values are slightly higher than RYGB.

CONCLUSIONS

We present the first bariatric weight loss percentile chart for OAGB. It allows evaluation of sufficient and insufficient weight loss at any post-operative point in a visual aspect. Furthermore, it predicts prospective outcomes and guides patient monitoring.

Development and validation of an interpretable machine learning-based calculator for predicting 5-year weight trajectories after bariatric surgery: a multinational retrospective cohort SOPHIA study

BACKGROUND

Weight loss trajectories after bariatric surgery vary widely between individuals, and predicting weight loss before the operation remains challenging. We aimed to develop a model using machine learning to provide individual preoperative prediction of 5-year weight loss trajectories after surgery.

METHODS

In this multinational retrospective observational study we enrolled adult participants (aged ≥18 years) from ten prospective cohorts (including ABOS [NCT01129297], BAREVAL [NCT02310178], the Swedish Obese Subjects study, and a large cohort from the Dutch Obesity Clinic [Nederlandse Obesitas Kliniek]) and two randomised trials (SleevePass [NCT00793143] and SM-BOSS [NCT00356213]) in Europe, the Americas, and Asia, with a 5 year follow-up after Roux-en-Y gastric bypass, sleeve gastrectomy, or gastric band. Patients with a previous history of bariatric surgery or large delays between scheduled and actual visits were excluded. The training cohort comprised patients from two centres in France (ABOS and BAREVAL). The primary outcome was BMI at 5 years. A model was developed using least absolute shrinkage and selection operator to select variables and the classification and regression trees algorithm to build interpretable regression trees. The performances of the model were assessed through the median absolute deviation (MAD) and root mean squared error (RMSE) of BMI.

FINDINGS

10 231 patients from 12 centres in ten countries were included in the analysis, corresponding to 30 602 patient-years. Among participants in all 12 cohorts, 7701 (75·3%) were female, 2530 (24·7%) were male. Among 434 baseline attributes available in the training cohort, seven variables were selected: height, weight, intervention type, age, diabetes status, diabetes duration, and smoking status. At 5 years, across external testing cohorts the overall mean MAD BMI was 2·8 kg/m2 (95% CI 2·6-3·0) and mean RMSE BMI was 4·7 kg/m2 (4·4-5·0), and the mean difference between predicted and observed BMI was -0·3 kg/m2 (SD 4·7). This model is incorporated in an easy to use and interpretable web-based prediction tool to help inform clinical decision before surgery.

INTERPRETATION

We developed a machine learning-based model, which is internationally validated, for predicting individual 5-year weight loss trajectories after three common bariatric interventions.

FUNDING

SOPHIA Innovative Medicines Initiative 2 Joint Undertaking, supported by the EU's Horizon 2020 research and innovation programme, the European Federation of Pharmaceutical Industries and Associations, Type 1 Diabetes Exchange, and the Juvenile Diabetes Research Foundation and Obesity Action Coalition; Métropole Européenne de Lille; Agence Nationale de la Recherche; Institut national de recherche en sciences et technologies du numérique through the Artificial Intelligence chair Apprenf; Université de Lille Nord Europe's I-SITE EXPAND as part of the Bandits For Health project; Laboratoire d'excellence European Genomic Institute for Diabetes; Soutien aux Travaux Interdisciplinaires, Multi-établissements et Exploratoires programme by Conseil Régional Hauts-de-France (volet partenarial phase 2, project PERSO-SURG).

Evidence-Based Classification for Post-bariatric Weight Regain from a Benchmark Registry Cohort of 18,403 Patients and Comparison with Current Criteria

INTRODUCTION

There is a need for a standardized, evidence-based classification of post-bariatric weight-regain, to investigate and compare revision procedures and to advice and treat patients in an evidence-based way.

METHODS

We used standard deviations (SD) of the highest (1-2 years) and latest (> 2 years) percentage total weight loss (%TWL) results after primary bariatric surgery from the Dutch Audit for Treatment of Obesity (DATO) bariatric registry as benchmarks for (above) average (≥ - 1SD), poor (- 1SD to - 2SD) and insufficient (< - 2SD) weight loss. Weight regain maintaining (above) average weight loss was called grade 1, weight regain towards poor weight loss grade 2, towards insufficient weight loss grade 3, with subgrades 2a/3a for below average weight loss from the start, and 2b/3b for weight regain from (above) average to below average weight loss. Patient characteristics and diabetes improvement/impairment were compared. Sensitivity and specificity of 14 existing weight regain criteria were calculated.

RESULTS

We analyzed 93,465 results from 38,830 patients (77.1% gastric bypass, 22.5% sleeve gastrectomy). The - 1SD thresholds for early and late weight loss approximated 25%TWL and 20%TWL, the - 2SD threshold for late weight loss 10%TWL. Weight regain could be analyzed for 18,403 patients (2.5-5.2 years follow-up). They regained mean 6.7 kg (5.4%TWL), with 66.8% grade 1 weight regain, 7.2% grade 2a, 7.4% grade 2b, 2.1% grade 3a, and 0.6% grade 3b. There were significant differences in comorbidities, gender, age, weight regain, diabetes impairment, and diabetes improvement across grades. Weight regain criteria from literature were extremely divers. None had high sensitivity.

CONCLUSION

The DATO classification for post-bariatric weight regain combines the extent of weight regain with evidence-based endpoints of weight loss. It differentiated weight regain maintaining (above) average weight loss, two intermediate grades, gradual weight regain with below average weight loss from the start (primary non-response) and steep weight regain towards insufficient weight loss (secondary non-response). The classification is superior to existing criteria and well supported by evidence.

Examining spousal and family support as predictors of long-term weight loss and remission of type 2 diabetes following bariatric surgery in Singapore: a retrospective cohort study

OBJECTIVES

Postoperative outcomes vary considerably across bariatric patients and may be related to psychosocial factors. In this study, we examined whether a patient's family support predicts postsurgical weight loss and the remission of type 2 diabetes mellitus (T2DM).

DESIGN

Retrospective cohort study in Singapore.

SETTING

Participants were recruited from a public hospital in Singapore.

PARTICIPANTS

Between 2008 and 2018, 359 patients completed a presurgical questionnaire before undergoing gastric bypass or sleeve gastrectomy.

OUTCOME MEASURES

As part of the questionnaire, patients described their family support in terms of structure (marital status, number of family members in the household) and function (marriage satisfaction, family emotional support, family practical support). Linear mixed-effects and Cox proportional-hazard models were used to examine whether these family support variables predicted percent total weight loss or T2DM remission up to 5 years postsurgery. T2DM remission was defined as glycated haemoglobin (HbA1c) <6.0% without medications.

RESULTS

Participants had a mean preoperative body mass index of 42.6±7.7 kg/m² and HbA1c (%) of 6.82±1.67. Marital satisfaction was found to be a significant predictor of postsurgical weight trajectories. Namely, patients who reported higher marital satisfaction were more likely to sustain weight loss than patients who reported lower marital satisfaction (β=0.92, SE=0.37, p=0.02). Family support did not significantly predict T2DM remission.

CONCLUSIONS

Given the link between marital support and long-term weight outcomes, providers could consider asking patients about their spousal relationships during presurgical counselling.

TRIAL REGISTRATION NUMBER

NCT04303611.

Obesity in South and Southeast Asia-A new consensus on care and management

Obesity is a chronic disease in which the abnormal or excessive accumulation of body fat leads to impaired health and increased risk of mortality and chronic health complications. Prevalence of obesity is rising rapidly in South and Southeast Asia, with potentially serious consequences for local economies, healthcare systems, and quality of life. Our group of obesity specialists from Bangladesh, Brunei Darussalam, India, Indonesia, Malaysia, Philippines, Singapore, Sri Lanka, Thailand, and Viet Nam undertook to develop consensus recommendations for management and care of adults and children with obesity in South and Southeast Asia. To this end, we identified and researched 12 clinical questions related to obesity. These questions address the optimal approaches for identifying and staging obesity, treatment (lifestyle, behavioral, pharmacologic, and surgical options) and maintenance of reduced weight, as well as issues related to weight stigma and patient engagement in the clinical setting. We achieved consensus on 42 clinical recommendations that address these questions. An algorithm describing obesity care is presented, keyed to the various consensus recommendations.

Revisional Surgery or Pharmacotherapy for Insufficient Weight Loss and Weight Regain After Primary Bariatric Procedure: a Descriptive Study

PURPOSE

Bariatric surgery is the most effective and durable treatment option for clinically severe obesity. Unfortunately, some degree of weight regain (WR) is common after nadir weight is achieved. Pharmacotherapy and revision surgery are potential options to treat this phenomenon. We aim to determine the efficacy of both approaches in patients with WR versus insufficient weight loss (IWL).

MATERIALS AND METHODS

We retrospectively reviewed a prospectively collected database of patients who underwent bariatric surgery from 2008 to 2018 with IWL or WR.

RESULTS

Of 422 patients with WR or IWL after bariatric surgery, 150 patients were placed on pharmacotherapy and 27 underwent revisional surgeries. Mean age of patients was 41.4 years and mean BMI was 42.1 kg/m². The most common conversion surgery was LSG to RYGB. % Total weight loss (TWL) was higher in IWL group (23.8% ± 11.0) compared to WR group (17.2% ± 7.9) in revisional surgery (p = 0.02). The converse was observed for pharmacotherapy, with %TWL 1.9% in the WR group compared to 0.7% in the IWL group (p = 0.0067).

CONCLUSION

Patients with IWL or WR had modest weight loss with adjunctive use of pharmacotherapy after primary bariatric surgery. Conversely, revisional surgery is an effective treatment for both IWL and WR.