Influence of mental and behavioral factors on weight loss after bariatric surgery: A systematic review and meta-analysis.

INTRODUCTION: Multiple factors are related to lower weight loss after bariatric surgery. This review and meta-analysis evaluates the influence of several mental and behavioral factors on weight loss. METHOD: Six electronic databases were searched. Percentage excess weight loss (%EWL) was calculated for all moderator and non-moderator groups of the variables: symptoms of depression, anxiety and binge eating, compliance, physical activity, quality of life, and body image. All moderators, surgery types, and follow-up moments were analyzed separately. RESULTS: In total, 75 articles were included in the review; 12 meta-analyses were conducted. Higher postoperative compliance to follow-up was associated with 6.86%-13.68% higher EWL. Preoperative binge eating was related to more weight loss at 24- and 36-month follow-up (7.97% and 11.79%EWL, respectively). Patients with postoperative binge eating symptoms had an 11.92% lower EWL. Patients with preoperative depressive symptoms lost equal weight compared to patients without symptoms. CONCLUSION: Despite the high heterogeneity between studies, a trend emerges suggesting that the presence of postoperative binge eating symptoms and lower postoperative compliance may be associated with less weight loss after bariatric-metabolic surgery. Additionally, preoperative depressive symptoms and binge eating do not seem to significantly impact weight loss.

Evaluation of Healthcare Utilisation and Expenditures in Persons with Type 2 Diabetes Undergoing Bariatric-Metabolic Surgery.

PURPOSE: Changes in healthcare utilisation and expenditures after bariatric-metabolic surgery (BMS) for people with type 2 diabetes mellitus (T2DM) are unclear. We used the Dutch national all-payer claims database (APCD) to evaluate utilisation and expenditures in people with T2DM who underwent BMS. METHODS: In this cohort study, patients with T2DM who had BMS in 2016 were identified in the APCD. This group was matched 1:2 to a control group with T2DM who did not undergo BMS based on age, gender and healthcare expenditures. Data on healthcare expenditures and utilisation were collected for 2013-2019. RESULTS: In total, 1751 patients were included in the surgery group and 3502 in the control group. After BMS, total median expenditures in the surgery group stabilised (€ 3156 to € 3120) and increased in the control group (€ 3174 to € 3434). Total pharmaceutical expenditures decreased 28% in the surgery group (€957 to €494) and increased 55% in the control group (€605 to €936). In the surgery group, 67.1% did not use medication for T2DM in 2019 compared to 13.3% in the control group. Healthcare use for microvascular complications increased in the control group, but not in the surgery group. CONCLUSION: BMS in people with T2DM stabilises healthcare expenditures and decreases medication use and care use for microvascular complications. In contrast, healthcare use and expenditures in T2DM patients who do not undergo surgery gradually increase over time. Due to the progressive nature of T2DM, it is expected that these differences will become larger in the long-term.

Preoperative Weight Gain Is Not Related to Lower Postoperative Weight Loss, But to Lower Total Weight Loss up to 3 Years After Bariatric-Metabolic Surgery.

INTRODUCTION: Weight loss prior to bariatric-metabolic surgery (BMS) is recommended in most bariatric centers. However, there is limited high-quality evidence to support mandatory preoperative weight loss. In this study, we will evaluate whether weight gain prior to primary BMS is related to lower postoperative weight loss. METHODS: A retrospective analysis of prospectively collected data was performed. Preoperative weight loss (weight loss from start of program to day of surgery), postoperative weight loss (weight loss from day of surgery to follow-up), and total weight loss (weight loss from start of program to follow-up) were calculated. Five groups were defined based on patients' preoperative weight change: preoperative weight loss of >5 kg (group I), 3-5 kg (group II), 1-3 kg (group III), preoperative stable weight (group IV), and preoperative weight gain >1 kg (group V). Linear mixed models were used to compare the postoperative weight loss between group V and the other four groups (I-IV). RESULTS: A total of 1928 patients were included. Mean age was 44 years, 78.6% were female, and preoperative BMI was 43.7 kg/m2. Analysis showed significantly higher postoperative weight loss in group V, compared to all other groups at 12, 24, and 36 months follow-up. Up to three years follow-up, highest total weight loss was observed in group I. CONCLUSION: Weight gain before surgery should not be a reason to withhold a bariatric-metabolic operation. However, patients with higher preoperative weight loss have higher total weight loss. Therefore, preoperative weight loss should be encouraged prior to bariatric surgery.

How to get back on track? Experiences of patients and healthcare professionals regarding weight recurrence and needs for an intervention after bariatric-metabolic surgery.

Background: Multidisciplinary lifestyle interventions are recommended as a first step in treating weight recurrence after bariatric-metabolic surgery (BMS). However, little is known about the experience of patients and healthcare professionals (HCP) with these interventions and how they should be tailored to the patients' needs. The aim of this study was to gain more insight into the experiences and needs of patients and HCP regarding weight recurrence after BMS and an intervention to get Back on Track. In addition, attitudes towards integrating e-Health into the care program were explored. Methods: A qualitative process evaluation of an intervention for weight recurrence, the Back on Track (BoT), was conducted by means of in-depth interviews and focus groups with 19 stakeholders, including patients and HCP involved in BoT. Interviews were transcribed verbatim. Data were analyzed through thematic analysis. Results: Patients and HCP reported a wide array of causes of weight recurrence. Patients found it difficult to decide when weight recurrence is problematic and when they should ask for help. Patients reported feeling like the exception and ashamed, therefore experiencing a high threshold to seek help. E-Health was seen as a promising way to improve tailoring, screening, autonomy for the patient, and accessible contact. Conclusion: Patients should be adequately counselled on weight recurrence after BMS and the importance of intervening early. It is important to lower the threshold for seeking help. For example by offering more long-term standard care or by adding e-Health to the intervention.

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).

Genetic variants associated with weight loss and metabolic outcomes after bariatric surgery: A systematic review.

The extent to which genetic variations contribute to interindividual differences in weight loss and metabolic outcomes after bariatric surgery is unknown. Identifying genetic variants that impact surgery outcomes may contribute to clinical decision making. This review evaluates current evidence addressing the association of genetic variants with weight loss and changes in metabolic parameters after bariatric surgery. A search was conducted using Medline, Embase, Scopus, Web of Science, and Cochrane Library. Fifty-two eligible studies were identified. Single nucleotide polymorphisms (SNPs) at ADIPOQ (rs226729, rs1501299, rs3774261, and rs17300539) showed a positive association with postoperative change in measures of glucose homeostasis and lipid profiles (n = 4), but not with weight loss after surgery (n = 6). SNPs at FTO (rs11075986, rs16952482, rs8050136, rs9939609, rs9930506, and rs16945088) (n = 10) and MC4R (rs11152213, rs476828, rs2229616, rs9947255, rs17773430, rs5282087, and rs17782313) (n = 9) were inconsistently associated with weight loss and metabolic improvement. Four studies examining the UCP2 SNP rs660339 reported associations with postsurgical weight loss. In summary, there is limited evidence supporting a role for specific genetic variants in surgical outcomes after bariatric surgery. Most studies have adopted a candidate gene approach, limiting the scope for discovery, suggesting that the absence of compelling evidence is not evidence of absence.

Body Image and Weight Loss Outcome After Bariatric Metabolic Surgery: a Mixed Model Analysis.

PURPOSE: As in nonsurgical weight loss populations, body image may partly explain differences in weight loss outcomes after surgery. The aim of this study was to determine the prospective association between body image and weight loss in a longitudinal cohort of patients up to 3 years after bariatric metabolic surgery. MATERIALS AND METHODS: The BODY-Q self-report questionnaire was used to assess body image. Linear mixed models evaluated associations of baseline body image with weight loss in the first year as well as associations of body image at 12 months and first-year change in body image with weight loss 12 to 36 months after surgery. RESULTS: Available body image data included 400 (100%), 371 (93%), 306 (77%), 289 (72%), and 218 (55%) patients at baseline and 4, 12, 24, and 36 months, respectively. Body image scores improved significantly until 12 months, followed by a gradual decline. Scores remained improved in comparison to baseline (ß = 31.49, 95% CI [27.8, 35.2], p < .001). Higher baseline body image was associated with less weight loss during the first year, and the effect size was trivial (ß = -0.05, 95% CI [-0.09, -0.01], p = .009). Body image and change in body image were not associated with weight loss 12 to 36 months after surgery. CONCLUSION: Body image improved after bariatric metabolic surgery. Although no clinically relevant associations of body image with weight loss were demonstrated, the gradual decline in body image scores underlines the importance of long-term follow-up with regular assessment of this aspect of quality of life.

Changes in Fat-Free Mass, Protein Intake and Habitual Physical Activity Following Roux-en-Y Gastric Bypass Surgery: A Prospective Study.

PURPOSE: Large inter-individual variations in post-bariatric fat-free mass loss (FFML) are observed, which might relate to differences in protein intake and physical activity across patients. We performed repetitive assessments of protein intake and physical activity before and after banded Roux-en-Y gastric bypass surgery, and examined its relations to FFML during 6 months of follow-up. MATERIALS AND METHODS: FFML (bio-impedance analyses), protein intake (24-h dietary recalls) and moderate-to-vigorous physical activity (MVPA; activPAL) were assessed in 28 patients (4 males, age 42 ± 12 years) before surgery and at 1-, 3- and 6-months post-surgery. Changes in protein intake and MVPA were evaluated with mixed model analysis, whereas associations with FFML were assessed by univariate regression analysis. RESULTS: Six-month FFML was -7.3 ± 3.6 kg. Protein intake decreased from 80 ± 29 g/day (pre-surgery) to 45 ± 26 g/day (1 month post-surgery (P < 0.001)) and did not improve thereafter (51 ± 21 g/day; P > 0.05). Seven participants (25%) consumed ≥ 60 g protein/day at 6 months post-surgery. Participants performed 7394 ± 2420 steps/day in 54 ± 20 min/day of MVPA, which did not change from pre- to post-surgery (P > 0.05). A higher step count (B = -0.002; 95%CI = [-0.004 - 0.000]; P = 0.048) and higher level of MVPA (B = -0.29; 95%CI = [-0.54 - -0.03]; P = 0.018) were related to a lower FFML. CONCLUSION: A lower post-surgery FFML was attributable to higher MVPA levels but not protein intake. This may be due to the low total protein intake and the observation that only a minority of patients achieved a protein intake ≥ 60 g/day. Future studies should focus on interventions to increase post-bariatric protein intake and MVPA levels.

Beyond Body Size: Focusing on Body Functionality to Improve Body Image Among Women Who Have Undergone Bariatric Surgery.

This study investigated a novel technique to improve body image among women who have undergone bariatric surgery-namely, by having them focus on their body functionality (everything the body can do, rather than how it looks). Participants were 103 women (Mage = 46.61) who had undergone bariatric surgery 5-7 months prior to the study. They were randomized to the 1-week online intervention, comprising three functionality-focused writing exercises (Expand Your Horizon; Alleva et al., 2015), or to a wait-list control group. Body appreciation, appearance and functionality satisfaction, body awareness, self-objectification, self-esteem, and self-kindness were assessed at pretest, posttest, and at 1-week and 3-month follow-up. Multilevel modeling analyses showed that, compared to the control, the intervention group experienced improved body appreciation at posttest, and these improvements persisted at both follow-ups. These findings were nonsignificant when intent-to-treat analyses were performed. Both available case and intent-to-treat analyses showed that all participants experienced improvements in facets of body image across time. Qualitative analyses of participants' responses to the intervention writing exercises provided more insight. Via coding reliability thematic analysis, we identified 11 themes that together provide evidence that intervention participants experienced facets of a more positive body image, while also facing challenges to their body image and well-being. Together, findings suggest that focusing on body functionality may contribute to improved body image among women who have undergone bariatric surgery, but effects may be nuanced compared to prior functionality research among general samples of women. The study was registered retrospectively (ClinicalTrials.gov; identifier NCT04883268).

The relationship of body image and weight: A cross-sectional observational study of a Dutch female sample.

Body image concerns may play a role in weight changing behaviour. The objective of this study was to assess body image in different weight groups. Participants reported satisfaction with (AE) and investment in (AO) appearance, and the discrepancy between current and ideal body size (BS). These scores were compared between weight groups based on body-mass index (BMI) using analysis of variance. One-sample t-tests and Cohen's d effect sizes examined the magnitude of differences within each weight group relative to neutral midpoints of the scales; cluster analysis identified body image profiles. A total of 27 896 women were included in this study. AE scores were highest for people with underweight and normal weight, AO scores were highest for the underweight group and lowest in class III obesity, and BS scores were largest in the obese groups (all p < .001) Cluster analysis identified eight body image profiles. In people with obesity, the most prevalent profiles included a preference for a smaller body and low satisfaction with appearance, but differed in investment in appearance (low vs. high). Most people with underweight were allocated to profiles showing high investment in their appearance, preference of a larger body, but differences in satisfaction with appearance (neutral vs. high). While people with a higher BMI have on average more body image concerns, different body image profiles exist in all weight groups. Future research should examine whether and which individuals in terms of body image profile may benefit more from weight interventions.

Using the BODY-Q to develop a prospective cohort of patients undergoing bariatric and body contouring surgery: A study protocol.

The BODY-Q is a patient-reported outcome measure designed to measure health-related quality of life, satisfaction with appearance and experience with healthcare in patients with obesity who undergo bariatric surgery and/or body contouring surgery after massive weight loss. The aim of this study is to collect long term PRO-data from patients living with obesity undergoing bariatric surgery, comparing patient undergoing or not undergoing body contouring surgery. This study will be a multicentre, prospective longitudinal cohort study with participation of three bariatric medical centres in the Netherlands. The BODY-Q will be used to measure the satisfaction with appearance and HRQL. Patients undergoing bariatric surgery, age >18 years and <65 years and who are able to read and understand Dutch can be included. All bariatric procedures are eligible for inclusion. Administration of the questionnaires will be done preoperatively for bariatric and body contouring surgery as well as at 3, 12, 24, 36, 48 and 60 months post-operatively. Patient-reported outcomes measurements are becoming more important with the shift to patient-centred healthcare. The collected longitudinal data can be helpful in determining the effectiveness and value of bariatric and body contouring surgery from the patient's perspective, and can contribute to patient tailored postoperative care.

Barriers to and Facilitators of Participation in Weight Loss Intervention for Patients with Suboptimal Weight Loss after Bariatric Surgery: A Qualitative Study among Patients, Physicians, and Therapists.

INTRODUCTION: Not all patients with suboptimal weight loss after bariatric surgery are willing to participate in postoperative behavioral intervention to improve their weight loss. The objective of this study was to explore barriers to and facilitators of participation in postoperative behavioral intervention. METHODS: Thirty semi-structured interviews were conducted with patients (18), physicians (6), and therapists (6) (i.e., psychologists, dieticians, or physiotherapists). A thematic analysis approach was used. RESULTS: Emotional responses caused by confrontation with suboptimal weight loss hampered patients' deliberation about participation; insufficient exploration of their need for help limited patients' ability to make informed decisions; patients were receptive to their physician's advice when their physician respected their autonomy; using visual weight loss graphs helped to explain suboptimal weight loss to patients; and financial costs and time constraints obstructed participation. CONCLUSIONS: To improve adequate intervention participation, healthcare providers should focus on emotion regulation, support patients in exploring their own need for help, and respect patients' autonomy.

Patient-Level Factors Associated with Health-Related Quality of Life and Satisfaction with Body After Bariatric Surgery: a Multicenter, Cross-Sectional Study.

BACKGROUND: Health-Related Quality of Life (HRQL) is a key outcome of success after bariatric surgery. Not all patients report improved HRQL scores postoperatively, which may be due to patient-level factors. It is unknown which factors influence HRQL after surgery. Our objective was to assess patient-level factors associated with HRQL after surgery. METHODS: This international cross-sectional study included 730 patients who had bariatric surgery. Participants completed BODY-Q scales pertaining to HRQL and satisfaction with body, and demographic characteristics were obtained. The sample was divided into three groups based on time since surgery: 0 - 1 year, 1 - 3 years and more than 3 years. Uni- and multivariable linear regression analyses were conducted to identify variables associated with the BODY-Q scales per group. RESULTS: The 0 - 1 year postoperative group included 377 patients (50.9%), the 1 - 3 years postoperative group 218 (29.4%) and the more than 3 years postoperative group 135 patients (18.2%). Lower current body-mass index (BMI), more weight loss (%TWL), being employed, having no comorbidities, higher age and shorter time since surgery were significantly associated with improved HRQL outcomes postoperatively. None of these factors influenced all BODY-Q scales. The effect of current BMI increased with longer time since surgery. CONCLUSION: Factors including current BMI, %TWL, employment status, presence of comorbidities, age and time since surgery were associated with HRQL postoperatively. This information may be used to optimize patient-tailored care, improve patient education and underline the importance of long-term follow-up with special attention to weight regain to ensure lasting improvement in HRQL.

Early Postoperative Weight Loss Predicts Weight Loss up to 5 Years After Roux-En-Y Gastric Bypass, Banded Roux-En-Y Gastric Bypass, and Sleeve Gastrectomy.

PURPOSE: Previous studies showed that patients with lower weight loss after bariatric surgery could be identified based on early postoperative weight loss. However, these studies had only 12-36-month follow-up. This study aimed to explore whether patients in the lowest weight loss quartile at 3 months had lower weight loss trajectories up to 5 years after Roux-en-Y gastric bypass (RYGB), banded Roux-en-Y gastric bypass (BRYGB), and sleeve gastrectomy (SG) surgery. METHODS: Weight was assessed preoperatively, and 3, 6, 9, 12, 24, 36, 48, and 60 months postoperatively. Patients were grouped into four categories based on quartiles of percentage total weight loss (%TWL) at 3-month follow-up. Results were compared between the lowest %TWL quartile group and other quartile groups. RESULTS: Patients underwent either RYGB (n=13,106; 72%), SG (n=3585; 20%), or BRYGB (n=1391, 8%) surgery. Weight loss trajectories of patients in the lowest %TWL quartile group remained lower than that of other quartile groups throughout a 5-year follow-up, for all three types of surgery. Patients in the lowest %TWL quartile group had higher age at surgery, higher baseline BMI, and were more likely to be male (in the SG group), and to suffer from diabetes, hypertension, dyslipidemia, and osteoarthritis. CONCLUSION: This study showed a positive association between weight loss at 3 and 12 to 60 months after bariatric surgery. Weight loss at 3 months after surgery could be used to identify patients whose anticipated weight loss trajectories are below average, to potentially improve their outcomes through early behavioral or medical interventions.

Outcomes of the first global multidisciplinary consensus meeting including persons living with obesity to standardize patient-reported outcome measurement in obesity treatment research.

Quality of life is a key outcome that is not rigorously measured in obesity treatment research due to the lack of standardization of patient-reported outcomes (PROs) and PRO measures (PROMs). The S.Q.O.T. initiative was founded to Standardize Quality of life measurement in Obesity Treatment. A first face-to-face, international, multidisciplinary consensus meeting was conducted to identify the key PROs and preferred PROMs for obesity treatment research. It comprised of 35 people living with obesity (PLWO) and healthcare providers (HCPs). Formal presentations, nominal group techniques, and modified Delphi exercises were used to develop consensus-based recommendations. The following eight PROs were considered important: self-esteem, physical health/functioning, mental/psychological health, social health, eating, stigma, body image, and excess skin. Self-esteem was considered the most important PRO, particularly for PLWO, while physical health was perceived to be the most important among HCPs. For each PRO, one or more PROMs were selected, except for stigma. This consensus meeting was a first step toward standardizing PROs (what to measure) and PROMs (how to measure) in obesity treatment research. It provides an overview of the key PROs and a first selection of the PROMs that can be used to evaluate these PROs.

Five-year weight loss, physical activity, and eating style trajectories after bariatric surgery.

BACKGROUND: Little research has taken individual variability in weight loss into account. Furthermore, physical activity (PA) and eating style (ES) have been linked only sporadically to weight loss longitudinally. OBJECTIVES: Identify and describe latent classes of weight loss, change of PA, and change of ES up to 5 years after surgery and investigate whether these trajectories are interrelated. SETTING: Multicenter outpatient clinic. METHODS: This is a retrospective study of data collected during standard treatment before and up to 5 years after surgery. Latent class growth analysis was used to identify trajectories of weight loss (percent total weight loss), PA (Baecke questionnaire), and ES (Dutch Eating Behavior Questionnaire). RESULTS: A total of 2785 patients were included. Follow-up rate was 84% at 1 year and 34% at 5 years. Analyses revealed 5 weight loss trajectories. Most patients followed an average, fairly stable weight loss trajectory (48%) or an above-average partial-regain trajectory (36%). Other patients followed a low-responder trajectory (9%), a rapid weight loss and weight regain trajectory (6%), or a continued weight loss trajectory (2%). Patients in the most favorable weight loss trajectory were more likely to also follow the most favorable ES trajectories. Patients following the most unfavorable weight loss trajectory were never also in the PA trajectory with an initial great increase in PA. CONCLUSION: This study distinguishes demographic and behavioral factors that may influence long-term weight loss trajectories after bariatric surgery. Trajectories varied mainly in magnitude and less in the pattern of weight loss over time, suggesting that very deviant patterns are rare.

The association between patient attendance to a perioperative group-based lifestyle program and weight loss after bariatric surgery.

BACKGROUND: To enable maximal and sustainable weight loss after bariatric surgery, bariatric lifestyle programs through multidisciplinary support are advised. OBJECTIVES: To assess the association between patient attendance to a perioperative group-based bariatric lifestyle program (GBLP) and weight loss up to 48 months postoperatively. SETTING: A multicenter retrospective cohort study in the Netherlands. METHODS: Patients who underwent primary laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) attended a GBLP in 2016 consisting of 18 sessions. A linear mixed model was used to assess the association between the patient attendance rate to the GBLP and total weight loss (%TWL). Independent predictors for the patient attendance rate and adequate %TWL were analyzed. RESULTS: A total of 3015 patients were included. Percentage of patients lost to follow-up was 5% at 1 year, 25% at 2 years, 34% at 3 years, and 42% at 4 years follow-up. Average TWL was 33% at 12 months after surgery, 33% at 24 months, 31% at 36 months, and 31% at 48 months. A small but significant adjusted positive association between the attendance rate and %TWL at 3 months until 36 months postoperatively was found (Beta between .03-.07), which disappeared at 48 months after surgery. Independent factors associated with a low attendance rate were younger age, male sex, and SG. Independent factors negatively associated with %TWL were male sex, SG, and diabetes. CONCLUSION: A higher patient attendance to GBLP sessions is associated with a small but significant increase in postoperative weight loss up to 3, but not 4 years after surgery.

Data Augmentation and Transfer Learning for Data Quality Assessment in Respiratory Monitoring.

Changes in respiratory rate have been found to be one of the early signs of health deterioration in patients. In remote environments where diagnostic tools and medical attention are scarce, such as deep space exploration, the monitoring of the respiratory signal becomes crucial to timely detect life-threatening conditions. Nowadays, this signal can be measured using wearable technology; however, the use of such technology is often hampered by the low quality of the recordings, which leads more often to wrong diagnosis and conclusions. Therefore, to apply these data in diagnosis analysis, it is important to determine which parts of the signal are of sufficient quality. In this context, this study aims to evaluate the performance of a signal quality assessment framework, where two machine learning algorithms (support vector machine-SVM, and convolutional neural network-CNN) were used. The models were pre-trained using data of patients suffering from chronic obstructive pulmonary disease. The generalization capability of the models was evaluated by testing them on data from a different patient population, presenting normal and pathological breathing. The new patients underwent bariatric surgery and performed a controlled breathing protocol, displaying six different breathing patterns. Data augmentation (DA) and transfer learning (TL) were used to increase the size of the training set and to optimize the models for the new dataset. The effect of the different breathing patterns on the performance of the classifiers was also studied. The SVM did not improve when using DA, however, when using TL, the performance improved significantly (p < 0.05) compared to DA. The opposite effect was observed for CNN, where the biggest improvement was obtained using DA, while TL did not show a significant change. The models presented a low performance for shallow, slow and fast breathing patterns. These results suggest that it is possible to classify respiratory signals obtained with wearable technologies using pre-trained machine learning models. This will allow focusing on the relevant data and avoid misleading conclusions because of the noise, when designing bio-monitoring systems.

The magnitude and progress of lean body mass, fat-free mass, and skeletal muscle mass loss following bariatric surgery: A systematic review and meta-analysis.

Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was -8.13 kg [95%CI -9.01; -7.26]. FFM loss and SMM loss were -8.23 kg [95%CI -10.74; -5.73] and -3.18 kg [95%CI -5.64; -0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.

Is the RAND-36 an Adequate Patient-reported Outcome Measure to Assess Health-related Quality of Life in Patients Undergoing Bariatric Surgery?

PURPOSE: The RAND-36 is the most frequently used patient-reported outcome measure (PROM) to evaluate health-related quality of life (HRQoL) in bariatric surgery. However, the RAND-36 has never been adequately validated in bariatric surgery. The purpose of this study was to validate the RAND-36 in Dutch patients undergoing bariatric surgery. MATERIAL AND METHODS: To validate the RAND-36, the following measurement properties were assessed in bariatric surgery patients: validity (the degree to which the RAND-36 measures what it purports to measure (HRQoL)), reliability (the extent to which the scores of the RAND-36 are the same for repeated measurement for patients who have not changed in HRQoL), responsiveness (the ability of the RAND-36 to detect changes in HRQoL over time). RESULTS: Two thousand one hundred thirty-seven patients were included. Validity was not adequate due to the irrelevance of some items and response options, the lack of items relevant to patients undergoing bariatric surgery, and the RAND-36 did not actually measure what it was intended to measure in this study (HRQoL in bariatric surgery patients). Reliability was insufficient for the majority of the scales (the scores of patients who had not changed in HRQoL were different when the RAND was completed a second time (intraclass correlation coefficient (ICC) values 0.10-0.69)). Responsiveness was insufficient. CONCLUSION: The RAND-36 was not supported by sufficient validation evidence in patients undergoing bariatric surgery, which means that the RAND-36 does not adequately measure HRQoL in this patient population. Future research studies should use PROMs that are specifically designed for assessing HRQoL in patients undergoing bariatric surgery.