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).

An Evaluation of the Implementation of the European Calcified Tissue Society Recommendations on the Prevention and Treatment of Osteoporosis Secondary to Bariatric Surgery

The purpose of this study was to evaluate the implementation of the European Calcified Tissue Society (ECTS) 2022 recommendations on the prevention and treatment of osteoporosis secondary to bariatric surgery. The ECTS 2022 recommendations were applied in a retrospective cohort of postmenopausal women and men aged 50 years and older who were undergoing or had already undergone bariatric surgery. Osteoporosis medication was indicated if any of the following criteria were met: (i) history of recent (within 2 years) fragility fracture after the age of 40 years, (ii) BMD T score ≤ -2 at any of the sites of measurement, and (iii) FRAX^® ≥ 20% for major osteoporotic fractures and/or ≥3% for hip fractures. Of the 170 patients (144 women, mean age 59 (55 to 63) years) included between February 2019 and March 2022, 33 were eligible for osteoporosis medication based on the ECTS 2022 recommendations, i.e., a prevalence of 19.6% [CI95%: 13.9%; 26.5%]. Most patients met the BMD T score ≤ -2 criterion (n = 25/170, 14.7% [CI95%: 9.7%; 20.9%]) and/or the history of recent fragility fracture criterion (n = 12/170, 7.1% [CI95%: 3.7%; 12.0%]). In this study, a fifth of our population was found to be eligible for osteoporosis medication after the application of the ECTS 2022 recommendations.

[Patient care pathway before bariatric surgery]

PATIENT CARE PATHWAY BEFORE BARIATRIC SURGERY In France, the preoperative period for bariatric surgery is the target of recommendations from the Haute Autorité de Santé (since 2009). During this period, which lasts at least 6 months, the multidisciplinary team must verify the indication (BMI, body mass index, greater than 40 kg/m2 or 35 kg/m2 with at least one comorbidity) and investigate possible contraindications, particularly psychological. This time is also necessary to understand the reasons for the excess weight and to initiate changes as part of a therapeutic education program. Medical examinations are carried out to detect possible co-morbidities and to establish a morphological assessment before surgery. At the end of this process, the patient must express his or her informed consent and the bariatric team will state the indication based on a multidisciplinary concertation. Experience shows the importance of the preoperative course in the patient's experience and for the good progress of the postoperative follow-up.

Meta-analysis of genome-wide DNA methylation and integrative omics of age in human skeletal muscle

BACKGROUND

Knowledge of age-related DNA methylation changes in skeletal muscle is limited, yet this tissue is severely affected by ageing in humans.

METHODS

We conducted a large-scale epigenome-wide association study meta-analysis of age in human skeletal muscle from 10 studies (total n = 908 muscle methylomes from men and women aged 18-89 years old). We explored the genomic context of age-related DNA methylation changes in chromatin states, CpG islands, and transcription factor binding sites and performed gene set enrichment analysis. We then integrated the DNA methylation data with known transcriptomic and proteomic age-related changes in skeletal muscle. Finally, we updated our recently developed muscle epigenetic clock (https://bioconductor.org/packages/release/bioc/html/MEAT.html).

RESULTS

We identified 6710 differentially methylated regions at a stringent false discovery rate <0.005, spanning 6367 unique genes, many of which related to skeletal muscle structure and development. We found a strong increase in DNA methylation at Polycomb target genes and bivalent chromatin domains and a concomitant decrease in DNA methylation at enhancers. Most differentially methylated genes were not altered at the mRNA or protein level, but they were nonetheless strongly enriched for genes showing age-related differential mRNA and protein expression. After adding a substantial number of samples from five datasets (+371), the updated version of the muscle clock (MEAT 2.0, total n = 1053 samples) performed similarly to the original version of the muscle clock (median of 4.4 vs. 4.6 years in age prediction error), suggesting that the original version of the muscle clock was very accurate.

CONCLUSIONS

We provide here the most comprehensive picture of DNA methylation ageing in human skeletal muscle and reveal widespread alterations of genes involved in skeletal muscle structure, development, and differentiation. We have made our results available as an open-access, user-friendly, web-based tool called MetaMeth (https://sarah-voisin.shinyapps.io/MetaMeth/).

Long-term outcomes of bariatric surgery in patients with bi-allelic mutations in the POMC, LEPR, and MC4R genes

BACKGROUND

Gene mutations in the leptin-melanocortin signaling cascade lead to hyperphagia and severe early onset obesity. In most cases, multimodal conservative treatment (increased physical activity, reduced caloric intake) is not successful to stabilize body weight and control hyperphagia.

OBJECTIVES

To examine bariatric surgery as a therapeutic option for patients with genetic obesity.

SETTING

Three major academic, specialized medical centers.

METHODS

In 3 clinical centers, we retrospectively analyzed the outcomes of bariatric surgery performed in 8 patients with monogenic forms of obesity with bi-allelic variants in the genes LEPR (n = 5), POMC (n = 2), and MC4R (n = 1).

RESULTS

In this group of patients with monogenic obesity, initial bariatric surgery was performed at a median age of 19 years (interquartile range [IQR], 16-23.8 yr). All patients initially experienced weight loss after each bariatric surgery, which was followed by substantial weight regain. In total, bariatric surgery led to a median maximum reduction of body weight of -21.5 kg (IQR, -36.3 to -2.9 kg), median percent excess weight loss (%EWL) of -47.5 %EWL (IQR, -57.6 to -28.9 %EWL). This body weight reduction was followed by median weight regain of 24.1 kg (IQR: 10.0 to 42.0 kg), leading to a final weight change of -24.2 % EWL (IQR: -37.6 to -5.4 %EWL) after a maximum duration of 19 years post surgery. In one patient, bariatric surgery was accompanied by significant complications, including vitamin deficiencies and hernia development.

CONCLUSION

The indication for bariatric surgery in patients with monogenic obesity based on bi-allelic gene mutations and its benefit/risk balance has to be evaluated very cautiously by specialized centers. Furthermore, to avoid an unsuccessful operation, preoperative genetic testing of patients with a history of early onset obesity might be essential, even more since novel pharmacological treatment options are expected.

NASH-related increases in plasma bile acid levels depend on insulin resistance

Background & Aims

Plasma bile acids (BAs) have been extensively studied as pathophysiological actors in non-alcoholic steatohepatitis (NASH). However, results from clinical studies are often complicated by the association of NASH with type 2 diabetes (T2D), obesity, and insulin resistance (IR). Here, we sought to dissect the relationship between NASH, T2D, and plasma BA levels in a large patient cohort.

Methods

Four groups of patients from the Biological Atlas of Severe Obesity (ABOS) cohort (Clinical Trials number NCT01129297) were included based on the presence or absence of histologically evaluated NASH with or without coincident T2D. Patients were matched for BMI, homeostatic model assessment 2 (HOMA2)-assessed IR, glycated haemoglobin, age, and gender. To study the effect of IR and BMI on the association of plasma BA and NASH, patients from the HEPADIP study were included. In both cohorts, fasting plasma BA concentrations were measured.

Results

Plasma BA concentrations were higher in NASH compared with No-NASH patients both in T2D and NoT2D patients from the ABOS cohort. As we previously reported that plasma BA levels were unaltered in NASH patients of the HEPADIP cohort, we assessed the impact of BMI and IR on the association of NASH and BA on the combined BA datasets. Our results revealed that NASH-associated increases in plasma total cholic acid (CA) concentrations depend on the degree of HOMA2-assessed systemic IR, but not on β-cell function nor on BMI.

Conclusions

Plasma BA concentrations are elevated only in those NASH patients exhibiting pronounced IR.

Lay summary

Non-alcoholic steatohepatitis (NASH) is a progressive liver disease that frequently occurs in patients with obesity and type 2 diabetes. Reliable markers for the diagnosis of NASH are needed. Plasma bile acids have been proposed as NASH biomarkers. Herein, we found that plasma bile acids are only elevated in patients with NASH when significant insulin resistance is present, limiting their utility as NASH markers.

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Bile acids have been studied as pathophysiological actors and biomarkers in NASH.

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Plasma BAs have been reported to be higher in NASH vs. No-NASH patients.

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Plasma BAs are altered in patients with T2D, IR, and obesity, risk factors for NASH.

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Thus, the independent association between plasma BA increases and NASH is unclear.

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NASH-associated increases in plasma BA depend on the degree of insulin sensitivity.

Eating in case of emotion dys-regulation, depression and anxiety: Different pathways to emotional eating in moderate and severe obesity

Emotion dys-regulation is thought to be involved in the development and maintenance of emotional eating (EE), notably through its links with anxious and depressive symptoms. AIM: The aims of the study were to: (a) examine the mediating effect of depressive and anxious symptoms on the relationship between emotion dys-regulation and EE in obesity and (b) compare those links with various degrees of obesity severity. One hundred and twenty patients with obesity, including 60 with "n" (MO) (30 ≤ BMI < 40) and 60 with "severe obesity" (SO) (BMI > 40), completed self-report measures of emotion dys-regulation, depression, anxiety and EE. Partial least square structural equation modelling and multi-group analyses were performed. Emotion dys-regulation was found to be significantly associated with EE only when the severity of obesity was taken into account. In addition, although the MO and SO groups reported similar levels of emotional and eating disorders, significant differences were found between the groups in pathways leading to EE. In MO, emotion dys-regulation was only associated with more EE through more anxiety. In SO, emotion dys-regulation was both directly and indirectly associated with more EE, but only through more depression in the latter. Emotion dys-regulation, anxiety and depression do not have the same impact on EE depending on the severity of obesity. Psychotherapeutic interventions should aim at reducing emotion dys-regulation in obesity from MO onwards, but the focus should be on the management of anxiety-related affects in MO and depression-related affects in SO.

Differential unfolded protein response in skeletal muscle from non-diabetic glucose tolerant or intolerant patients with obesity before and after bariatric surgery

AIMS

Not all people with obesity become glucose intolerant, suggesting differential activation of cellular pathways. The unfolded protein response (UPR) may contribute to the development of insulin resistance in several organs, but its role in skeletal muscle remains debated. Therefore, we explored the UPR activation in muscle from non-diabetic glucose tolerant or intolerant patients with obesity and the impact of bariatric procedures.

METHODS

Muscle biopsies from 22 normoglycemic (NG, blood glucose measured 120 min after an oral glucose tolerance test, G120 < 7.8 mM) and 22 glucose intolerant (GI, G120 between 7.8 and 11.1 mM) patients with obesity were used to measure UPR activation by RTqPCR and western blot. Then, UPR was studied in biopsies from 7 NG and 7 GI patients before and 1 year after bariatric surgery.

RESULTS

Binding immunoglobulin protein (BIP) protein was ~ 40% higher in the GI compared to NG subjects. Contrastingly, expression of the UPR-related genes BIP, activating transcription factor 6 (ATF6) and unspliced X-box binding protein 1 (XBP1u) were significantly lower and C/EBP homologous protein (CHOP) tended to decrease (p = 0.08) in GI individuals. While BIP protein positively correlated with fasting blood glucose (r = 0.38, p = 0.01), ATF6 and CHOP were associated with G120 (r = - 0.38 and r = - 0.41, p < 0.05) and the Matsuda index (r = 0.37 and r = 0.38, p < 0.05). Bariatric surgery improved metabolic parameters, associated with higher CHOP expression in GI patients, while ATF6 tended to increase (p = 0.08).

CONCLUSIONS

CHOP and ATF6 expression decreased in non-diabetic GI patients with obesity and was modified by bariatric surgery. These genes may contribute to glucose homeostasis in human skeletal muscle.

A series of severe neurologic complications after bariatric surgery in France: the NEUROBAR Study

BACKGROUND

Neurologic complications after bariatric surgery are rare, but can have dramatic consequences. Little data are available on this topic.

OBJECTIVES

The aim of the Neurologic complications after BARiatric surgery (NEUROBAR) study was to define, which factors (anthropometric, nutritional, surgical, etc.) were frequently associated with neurologic complications after bariatric surgery.

SETTINGS

Data were collected by the French Centers of Obesity Care Management hosted in University Hospitals.

METHODS

An online standardized questionnaire was designed and submitted to the 37 French Centers of Obesity Management. This questionnaire included items about patient characteristics, bariatric surgery, neurologic complications, nutritional status, and management. Patients were retrospectively included from January 2010 to November 2018.

RESULTS

Thirteen centers included 38 patients (34 females and 4 males) with neurologic complications after bariatric surgery. The 2 main bariatric procedures were gastric bypass and sleeve gastrectomy. More than half of the patients with neurologic complications had a surgical complication after bariatric surgery (53%) and gastrointestinal symptoms, including vomiting (53%). Vitamin B deficiencies were frequent (74%) including at least 47% of cases with deficiency in Vitamin B1.

CONCLUSION

Early identification of patients with surgical complications and gastrointestinal symptoms after bariatric surgery could help prevent neurologic complications related to nutritional deficiencies.

Decreased emotional eating behavior is associated with greater excess weight loss five years after gastric banding

While significant weight loss has been observed in the first two years following adjustable gastric banding (AGB), research on the long-term effectiveness of gastric restriction (e.g., 5 years) both on weight loss and eating behavior changes is scarce. The present study examined obese patients' changes in eating behavior preoperatively and 5 years after AGB and examined their associations with excess weight loss (EWL). Specifically, we focused on the association between the modification of three eating behavior profiles (i.e., restrained eating, emotional eating and external eating) and %EWL at 5 years. Among the 197 participants who underwent AGB, 136 completed the clinical assessments (weight, depression with the BDI, eating behavior with the DEBQ) before surgery, and after 5 years. Resultsshowed that the mean percentage of EWL was 47% after 5 years. Moreover, patients reported lower emotional eating and external eating after 5 years in comparison to the baseline, whereas there were no differences concerning restrained eating. Importantly, patients who presented higher %EWL at 5 years also reported a greater decrease in emotional eating between the two sessions than those with low %EWL. Our study underlines that eating behaviors are major variables involved in weight loss after gastric restriction. Results showed that emotional and external eating decreased significantly at 5 years whereas restrained eating behaviors did not vary between the pre- and postoperative stages. Moreover, the data suggest that a decrease in emotional eating accounts for the extent of EWL.

Interoceptive reliance as a major determinant of emotional eating in adult obesity

This study examined the association between emotional eating, emotion dysregulations, and interoceptive sensibility in 116 patients with obesity by distinguishing an “awareness” and a “reliance” component of interoceptive sensibility. Deficits in interoceptive awareness were only associated with more emotional eating in obesity through less interoceptive reliance and more emotion dysregulations. The results suggest that good interoceptive awareness can increase the risk of emotional eating if not supported by good interoceptive reliance. Interoceptive reliance, like the ability to trust, positively consider, and positively use inner sensations, should be a privileged target of psychotherapeutic interventions in obesity.

Difficulties in emotion regulation and deficits in interoceptive awareness in moderate and severe obesity

PURPOSE

Difficulties in emotion regulation and deficits in interoceptive awareness may be responsible for overeating and weight gain in obesity by increasing the risks of problematic eating behaviors. This study aimed to: (1) examine emotion regulation difficulties and interoceptive deficits in obesity; (2) compare the emotion regulation and interoceptive abilities of moderately and severely obese patients.

METHODS

Participants were recruited through the university, diabetology centers and bariatric surgery departments. A total of 165 participants were categorized in three groups, matched by age and gender, according to their Body Mass Index (BMI). The severely obese (SO), moderately obese (MO) and normal weight (NW) groups were constituted of 55 participants each. Self-report questionnaires were used to assess emotion regulation difficulties (CERQ-DERS) and interoceptive awareness (MAIA-FFMQ).

RESULTS

Overall, obese participants reported more emotion regulation difficulties and less interoceptive awareness than NW participants did. They also reported a lack of planning strategies and emotional awareness, as well as less ability to observe, notice and trust body sensations. No differences in emotion regulation and interoceptive abilities were found between MO and SO participants.

CONCLUSIONS

Emotion regulation and interoceptive awareness should be targeted in the psychotherapeutic care of obese people, regardless of their BMI.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

[Bariatric surgery: The clinical pathway of the patient with a severe obesity surgery]

Bariatric surgery is developing parallel to the increasing prevalence of severe obesity. Patient' care is guided by professional recommendations highlighting the key-role of multidisciplinary team in perioperative management. The clinical pathway, particularly adapted for bariatric surgery, allows the optimization of resources allocation and healthcare planning while improving the quality and efficiency (performance) of healthcare. The assessment (and adjustments) of clinical pathways allows measuring the impact of quality of care, patients' outcome and the effectiveness of healthcare. Additionally, the development of a clinical pathway fosters multidisciplinary team cohesion around the project.

[Nutritional follow-up after bariatric surgery]

Lifelong monitoring after weight loss surgery is recommended in order to check the efficacy of the procedure and to identify complications. Particular attention must be paid to the nutritional status of pregnant women and in the event of surgical complications. Education programmes must be offered at every stage of the care pathway in order to favour the compliance required for the follow-up.

Bariatric Surgery Reduces Features of Nonalcoholic Steatohepatitis in Morbidly Obese Patients

BACKGROUND & AIMS

The effects of bariatric surgery in patients with nonalcoholic fatty liver disease (NASH) are not well established. We performed a prospective study to determine the biological and clinical effects of bariatric surgery in patients with NASH.

METHODS

From May 1994 through May 2013, one hundred and nine morbidly obese patients with biopsy-proven NASH underwent bariatric surgery at the University Hospital of Lille, France (the Lille Bariatric Cohort). Clinical, biological, and histologic data were collected before and 1 year after surgery.

RESULTS

One year after surgery, NASH had disappeared from 85% of the patients (95% confidence interval [CI]: 75.8%-92.2%). Compared with before surgery, patients had significant reductions in mean ± SD body mass index (BMI, from 49.3 ± 8.2 to 37.4 ± 7) and level of alanine aminotransferase (from 52.1 ± 25.7 IU/L to 25.1 ± 20 IU/L); mean levels of γ-glutamyltransferases were reduced from 51 IU/L before surgery (interquartile range [IQR], 34-87 IU/L) to 23 IU/L afterward (IQR, 14-33 IU/L) and mean insulin resistance index values were reduced from 3.6 ± 0.5 to 2.9 ± 0.5 (P < .01 for each comparison). NASH disappeared from a higher proportion of patients with mild NASH before surgery (94%) than severe NASH (70%) (P < .05) according to Brunt score. In histologic analysis, steatosis was detected in 60% of the tissue before surgery (IQR, 40%-80%) but only 10% 1 year after surgery (IQR, 2.5%-21.3%); the mean nonalcoholic fatty liver disease score was reduced from 5 (IQR, 4-5) to 1 (IQR, 1-2) (each P < .001). Hepatocellular ballooning was reduced in 84.2% of samples (n = 69; 95% CI: 74.4-91.3) and lobular inflammation in 67.1% (n = 55; 95% CI: 55.8-77.1). According to Metavir scores, fibrosis was reduced in 33.8% of patients (95% CI: 23.6%-45.2%). Patients whose NASH persisted 1 year after surgery (n = 12) had lost significantly less weight (change in BMI, 9.1 ± 1.5) than those without NASH (change in BMI, 12.3 ± 0.6) (P = .005). Patients who underwent laparoscopic gastric banding lost less weight (change in BMI, 6.4 ± 0.7) than those who underwent gastric bypass (change in BMI, 14.0 ± 0.5) (P < .0001), and a higher proportion had persistent NASH (30.4% vs 7.6% of those with gastric bypass; P = .015).

CONCLUSIONS

Bariatric surgery induced the disappearance of NASH from nearly 85% of patients and reduced the pathologic features of the disease after 1 year of follow-up. It could be a therapeutic option for appropriate morbidly obese patients with NASH who do not respond to lifestyle modifications. More studies are needed to determine the long-term effects of bariatric surgery in morbidly obese patients with NASH.

Does pregnancy influence long-term results of bariatric surgery?

BACKGROUND

Bariatric surgery is performed mostly on obese women of reproductive age. Many authors have studied pregnancy outcomes after bariatric surgery. Only a small number of studies have analyzed the impact of maternity on the results of bariatric surgery.

OBJECTIVES

To study the effect of pregnancy on long-term outcomes of bariatric surgery.

SETTING

Lille University Hospital.

METHODS

A retrospective study was conducted on 591 women aged 18 to 42 years who had undergone laparoscopic adjustable gastric band (LAGB) surgery or laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery between 1996 and 2012. A comparison of the results after a 5-year follow-up was performed between patients who became pregnant after their bariatric surgery (pregnant group, n = 84) and postoperative nonpregnant women (nonpregnant group, n = 507).

RESULTS

At the 5-year visit, 84.8% patients were seen. The preoperative body mass index (BMI) was the same in the 2 groups (pregnant group: 47.8±6.9 kg/m(2); nonpregnant group: 47.5±7.2 kg/m(2); P = .755). The percentage of excess weight loss (%EWL) was lower in the pregnant group at 2 years (pregnant group = 45.9±24.6%; nonpregnant group = 56.9±28.6%, P = .002) but was similar at 5 years (47.7±27.7% versus 49.9±28.9%, P = .644). The decrease in co-morbidities was similar after 5 years. The gestational weight gain (GWG) was higher when the band was deflated during pregnancy (GWG =+12.7±10.5 kg) compared to the band without fluid removal (GWG =+4.9±7 kg) or laparoscopic Roux-en-Y gastric bypass (GWG =+4.4±1.1 kg) (P< .05).

CONCLUSIONS

Pregnancy after bariatric surgery slows down postoperative weight loss but does not affect weight results at 5-year follow-up.

Long-term metabolic outcome and quality of life after laparoscopic adjustable gastric banding in obese patients with type 2 diabetes mellitus or impaired fasting glucose

BACKGROUND

The long-term outcome of type 2 diabetes mellitus after laparoscopic adjustable gastric banding (LAGB) is unknown.

METHODS

A longitudinal cohort study was undertaken of patients with grade 3 obesity and type 2 diabetes or impaired fasting glucose (IFG) undergoing LAGB. Metabolic outcomes and quality of life (QoL) were assessed before and 5 years after LAGB.

RESULTS

At 5 years, data for 22 out of 23 patients with type 2 diabetes and 51 out of 53 with IFG were available. Mean(s.d.) excess weight loss was 41(25) and 41(27) per cent in patients with type 2 diabetes and IFG respectively, and was associated with a significant decrease in haemoglobin (Hb) A1c, fasting and postprandial blood glucose, insulin and triglyceride levels, and in liver steatosis. There were significant increases in insulin sensitivity, beta-cell function, disposition index, high-density lipoprotein-cholesterol and QoL (Nottingham Health Profile). Good metabolic control (HbA1c 7 per cent or less) was obtained in 13 diabetic patients, but complete diabetes remission was maintained in only four. Longer duration of diabetes, and poor preoperative glucose control and beta-cell function at baseline were associated with a less favourable outcome.

CONCLUSION

LAGB improved metabolic outcomes and QoL in patients with grade 3 obesity with IFG or type 2 diabetes but rarely led to prolonged remission in long-standing diabetes.

Prospective study of the long-term effects of bariatric surgery on liver injury in patients without advanced disease

BACKGROUND & AIMS

Severe obesity is implicated in development of nonalcoholic fatty liver disease (NAFLD). Bariatric surgery induces weight loss and increases survival time of obese patients, but little is known about its effects on liver damage. We performed a 5-year prospective study to evaluate fibrosis and nonalcoholic steatosis (NASH) in severely obese patients after bariatric surgery.

METHODS

Bariatric surgery was performed on 381 patients. Clinical and biological data, along with liver biopsies, were collected before and at 1 and 5 years after surgery.

RESULTS

Five years after surgery, levels of fibrosis increased significantly, but 95.7% of patients maintained a fibrosis score <or= F1. The percentage of patients with steatosis decreased from 37.4% before surgery to 16%, the NAFLD score from 1.97 to 1, ballooning from 0.2 to 0.1. Inflammation remained unchanged. The percentage of patients with probable or definite NASH decreased significantly over 5 years, from 27.4% to 14.2%. The kinetics of insulin resistance (IR) paralleled that of steatosis and ballooning; the greatest improvements occurred within the first year and were sustained 5 years later. Steatosis and ballooning occurred more frequently in patients with a refractory IR profile. In multivariate analysis, the refractory IR profile independently predicted the persistence of steatosis and ballooning 5 years later.

CONCLUSIONS

Five years after bariatric surgery for severe obesity, almost all patients had low levels of NAFLD, whereas fibrosis slightly increased. Steatosis and ballooning were closely linked to IR; long-term effects could be predicted by early improvement in IR.