Breast Cancer Risk After Bariatric Surgery and Influence of Insulin Levels: A Nonrandomized Controlled Trial.

Importance: Obesity and insulin are risk factors for breast cancer, and retrospective studies suggest bariatric surgery reduces breast cancer risk in women. However, long-term prospective data on breast cancer risk after bariatric surgery and the role of baseline insulin levels are lacking. Objective: To examine if bariatric surgery is associated with breast cancer incidence in women and if treatment benefit is modified by baseline insulin levels. Design, Setting, and Participants: The Swedish Obese Subjects (SOS) study was a nonrandomized intervention trial designed to investigate the long-term effects of bariatric surgery on obesity-related mortality and morbidity. Study recruitment took place between 1987 and 2001, and median (IQR) follow-up time was 23.9 years (20.1-27.1) years. The study was conducted at 25 public surgical departments and 480 primary health care centers in Sweden and included 2867 women aged 37 to 60 years and with body mass index 38 or greater (calculated as weight in kilograms divided by height in meters squared). Intervention: In the surgery group (n = 1420), 260 women underwent gastric banding, 970 vertical banded gastroplasty, and 190 gastric bypass. The remaining contemporaneously matched control individuals (n = 1447) received usual obesity care. Main Outcome and Measures: Breast cancer, the main outcome of this secondary report, was not a predefined outcome in the SOS study. Breast cancer events were identified in the Swedish National Cancer Registry. Results: The study population comprised 2867 women with a mean (SD) age of 48.0 (6.2) years. During follow-up, there were 154 breast cancer events, 66 in the surgery group and 88 in the usual care group, and a decreased risk of breast cancer was observed in the bariatric surgery group (hazard ratio [HR], 0.68; 95% CI, 0.49-0.94; P = .019; adjusted HR, 0.72; 95% CI, 0.52-1.01; P = .06). The surgical treatment benefit on breast cancer risk was greater in women with baseline insulin levels above the median 15.8 µIU/L (HR, 0.48; 95% CI, 0.31-0.74; P = .001; adjusted HR, 0.55; 95% CI, 0.35-0.86; P = .008) compared to those below (HR, 0.95; 95% CI, 0.59-1.53; P = .84; adjusted HR, 1.01; 95% CI, 0.61-1.66; P = .97; interaction P = .02). Conclusions and Relevance: This prospective clinical trial indicated a reduced risk of breast cancer after bariatric surgery in women with obesity. The surgical treatment benefit was predominantly seen in women with hyperinsulinemia. Trial Registration: ClinicalTrials.gov Identifier: NCT01479452.

Long-term incidence of haematological cancer after bariatric surgery or usual care in the Swedish Obese Subjects study: a prospective cohort study.

BACKGROUND: Bariatric surgery in people with obesity is associated with a reduced overall cancer risk. Retrospective studies indicate that bariatric surgery specifically might reduce the risk of haematological cancers, but there is an absence of data from long-term, prospective studies. We therefore studied the association between bariatric surgery and haematological cancer in the Swedish Obese Subjects study. METHODS: The prospective controlled Swedish Obese Subjects study was designed to compare overall mortality in people who underwent bariatric surgery (n=2007) and usual care (n=2040). Participants were recruited through campaigns in mass media and at 480 primary health-care centres all over Sweden. The inclusion criteria were an age of 37-60 years and a BMI of 34 kg/m2 or more in men and 38 kg/m2 or more in women before or at the time of the examination. Haematological cancer events, including malignant lymphoma, myeloma, myeloproliferative neoplasms, as well as acute and chronic leukaemias, were captured from the Swedish Cancer Registry. The main outcome of this study was haematological cancer incidence and mortality. This study is registered with ClinicalTrials.gov (NCT01479452) and is ongoing. FINDINGS: A total of 4047 individuals with obesity were enrolled between Sept 1, 1987, and Jan 31, 2001. Overall, 34 participants in the surgery group and 51 participants in the usual care control group were diagnosed with haematological cancer during follow-up (hazard ratio [HR] 0·60; 95% CI 0·39-0·92; p=0·020). Moreover, there were three deaths by haematological cancer in the surgery group and 13 deaths in the control group (0·22; 0·06-0·76; p=0·017). Surgery was also associated with a reduced incidence of lymphoma (0·45; 0·23-0·88; p=0·020). A significant difference in treatment effect between men and women was found; bariatric surgery was associated with reduced incidence of haematological cancer in women (0·44; 0·26-0·74; p=0·002), but not in men (1·35; 0·58-3·17; p=0·489; interaction p=0·031). INTERPRETATION: Bariatric surgery is associated with a reduced incidence of haematological cancer, specifically in women. Health-care providers and policy makers working in the field of cancer prevention should consider bariatric surgery a primary prevention resource for people with obesity. FUNDING: The Swedish Research Council, the Swedish State under the agreement between the Swedish Government and the county councils, the Avtal om Läkarutbildning och Forskning agreement, the Health & Medical Care Committee of the Region Västra Götaland, the Swedish Heart Lung Foundation, Gothenburg Medical Society, and the Adlerbert Research Foundation. TRANSLATION: For the Swedish translation of the abstract see Supplementary Material section.

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).

Life expectancy after bariatric surgery or usual care in patients with or without baseline type 2 diabetes in Swedish Obese Subjects.

OBJECTIVES: To determine life expectancy and causes of death after bariatric surgery in relation to baseline type 2 diabetes (T2D) in the prospective, Swedish Obese Subjects study. METHODS: The study included 2010 patients with obesity who underwent bariatric surgery and 2037 matched controls, eligible for surgery. The surgery group underwent gastric bypass (n = 265), banding (n = 376), or vertical banded gastroplasty (n = 1369). The control group (n = 2037) received usual obesity care. Causes of death were obtained from the Swedish Cause of Death Register, case sheets and autopsy reports, in patients with baseline T2D (n = 392 surgery patients/n = 305 controls) or non-T2D (n = 1609 surgery patients/n = 1726 controls) during a median follow-up 26 years. RESULTS: In T2D and non-T2D subgroups, bariatric surgery was associated with increased life expectancy (2.1, 95% confidence interval (95% CI) 0.2-4.0; and 1.6, 0.5-2.7 years, respectively) and reduced overall mortality (adjusted hazard ratio (adjHR) = 0.77, 95% CI: 0.61-0.97; and 0.82, 0.72-0.94, respectively), and the treatment benefit was similar (interaction p = 0.615). Bariatric surgery was associated with reduced cardiovascular mortality in both subgroups (adjHR = 0.65, 95% CI: 0.46-0.91; and 0.70, 0.55-0.88, respectively (interaction p = 0.516)). CONCLUSIONS: Bariatric surgery is associated with similar reduction of overall and cardiovascular mortality and increased life expectancy regardless of baseline diabetes status.

Non-alcohol substance use disorder after bariatric surgery in the prospective, controlled Swedish Obese Subjects study.

OBJECTIVE: The goal of this study was to investigate whether bariatric surgery is associated with substance use disorder (SUD) with substances other than alcohol. METHODS: The prospective, controlled Swedish Obese Subjects study enrolled 2010 patients with obesity who underwent bariatric surgery (gastric bypass n = 265; vertical banded gastroplasty n = 1369; gastric banding n = 376) and 2037 matched control individuals receiving usual obesity care. Participants with SUD other than alcohol use disorder were identified using International Statistical Classification of Diseases (ICD) codes from the Swedish National Patient Register (covering treatment in hospital but not primary care). Those with a history of non-alcohol SUD were excluded. Median follow-up was 23.8 years. RESULTS: During follow-up, non-alcohol SUD incidence rates per 1000 person-years with 95% CI were 1.6 (0.8-3.1), 0.8 (0.5-1.2), 1.1 (0.5-2.2), and 0.6 (0.4-0.8) for gastric bypass, vertical banded gastroplasty, gastric banding, and control individuals, respectively. Only gastric bypass was associated with increased incidence of non-alcohol SUD (adjusted hazard ratio 2.54 [95% CI: 1.14-5.65], p = 0.022) compared with control participants. CONCLUSIONS: Gastric bypass surgery was associated with increased risk of non-alcohol SUD, and this should be considered in long-term postoperative care.

Evolution of age-related mutation-driven clonal haematopoiesis over 20 years is associated with metabolic dysfunction in obesity.

BACKGROUND: Haematopoietic clones caused by somatic mutations with ≥2% variant allele frequency (VAF) increase with age and are linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones (VAF<2%) are also associated with adverse outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes in individuals with obesity treated by usual care or bariatric surgery (a treatment that improves metabolic status), and to examine the expansion of clones in relation to age and metabolic dysregulation over up to 20 years. METHODS: Clonal haematopoiesis-driver mutations (CHDMs) were identified in blood samples from participants of the Swedish Obese Subjects intervention study. Using an ultrasensitive assay, we analysed single-timepoint samples from 1050 individuals treated by usual care and 841 individuals who had undergone bariatric surgery, and multiple-timepoint samples taken over 20 years from a subset (n = 40) of the individuals treated by usual care. FINDINGS: In this explorative study, prevalence of CHDMs was similar in the single-timepoint usual care and bariatric surgery groups (20.6% and 22.5%, respectively, P = 0.330), with VAF ranging from 0.01% to 31.15%. Clone sizes increased with age in individuals with obesity, but not in those who underwent bariatric surgery. In the multiple-timepoint analysis, VAF increased by on average 7% (range -4% to 24%) per year and rate of clone growth was negatively associated with HDL-cholesterol (R = -0.68, 1.74 E-04). INTERPRETATION: Low HDL-C was associated with growth of haematopoietic clones in individuals with obesity treated by usual care. FUNDING: The Swedish Research Council, The Swedish state under an agreement between the Swedish government and the county councils, the ALF (Avtal om Läkarutbildning och Forskning) agreement, The Swedish Heart-Lung Foundation, The Novo Nordisk Foundation, The European Research Council, The Netherlands Organisation for Scientific Research.

Correction: Copy number of pancreatic polypeptide receptor gene NPY4R correlates with body mass index and waist circumference.

[This corrects the article DOI: 10.1371/journal.pone.0194668.].

Human adipose tissue gene expression of solute carrier family 19 member 3 (SLC19A3); relation to obesity and weight-loss.

OBJECTIVE: Adipose tissue is a specialized endocrine organ that is involved in modulating whole-body energy homeostasis and expresses a specific subset of genes, which may play a role in adipose tissue metabolism. The aim of this study was to search for novel adipose tissue-specific genes using a tissue panel of RNAseq expression profiles. METHODS: RNAseq expression profiles from 53 human tissues were downloaded from the GTex database. SLC19A3 expression was analyzed by microarray or real-time PCR in two sets of paired subcutaneous and omental adipose tissue samples, in two studies with adipose tissue from persons with high or low body mass index (BMI), in adipose tissue from patients who underwent weight loss with a very-low caloric diet and during preadipocyte-adipocyte differentiation. RESULTS: The RNAseq-based tissue distribution expression screen identified SLC19A3 (encoding the thiamine transporter 2) as adipose tissue-specific. SLC19A3 expression was higher in subcutaneous compared with omental adipose tissue in both sample sets (p = 0.043 and p < 0.001). Preadipocyte differentiation towards adipocytes resulted in increased SLC19A3 gene expression (p = 0.018 or less at all-time points). Subcutaneous adipose tissue expression of SLC19A3 was lower in persons with high BMI in both cohorts (p = 0.008, and p < 0.001) and increased during a weight-loss intervention (p = 0.006). CONCLUSION: The specific adipose tissue expression pattern of SLC19A3, together with its regulation in obesity and during weight loss, indicate that it plays a key role in adipocyte metabolism.

Association of Bariatric Surgery With Cancer Incidence in Patients With Obesity and Diabetes: Long-term Results From the Swedish Obese Subjects Study.

OBJECTIVE: Obesity and type 2 diabetes are associated with serious adverse health effects, including cancer. Although bariatric surgery has been shown to reduce cancer risk in patients with obesity, the effect of bariatric surgery on cancer risk in patients with obesity and diabetes is less studied. We therefore examined the long-term incidence of cancer after bariatric surgery and usual care in patients with obesity and diabetes in the matched prospective Swedish Obese Subjects (SOS) study. RESEARCH DESIGN AND METHODS: The SOS study examines long-term outcomes following bariatric surgery or usual care. The current analysis includes 701 patients with obesity and type 2 diabetes at baseline, 393 of whom underwent bariatric surgery and 308 who received conventional obesity treatment. Information on cancer events was obtained from the Swedish National Cancer Register. Median follow-up time was 21.3 years (interquartile range 17.6-24.8 years, maximum 30.7 years). RESULTS: During follow-up, the incidence rate for first-time cancer was 9.1 per 1,000 person-years (95% CI 7.2-11.5) in patients with obesity and diabetes treated with bariatric surgery and 14.1 per 1,000 person-years (95% CI 11.2-17.7) in patients treated with usual obesity care (adjusted hazard ratio 0.63 [95% CI 0.44-0.89], P = 0.008). Moreover, surgery was associated with reduced cancer incidence in women (0.58 [0.38-0.90], P = 0.016), although the sex-treatment interaction was nonsignificant (P = 0.630). In addition, diabetes remission at the 10-year follow-up was associated with reduced cancer incidence (0.40 [0.22-0.74], P = 0.003). CONCLUSIONS: These results suggest that bariatric surgery prevents cancer in patients with obesity and diabetes and that durable diabetes remission is associated with reduced cancer risk.

Long-term incidence of hypoglycaemia-related events after bariatric surgery or usual care in the Swedish Obese Subjects study: A register-based analysis.

AIMS: To examine the incidence of hypoglycaemia-related events over a period of up to 31 years in patients treated with bariatric surgery in the prospective, controlled Swedish Obese Subjects (SOS) study. MATERIALS AND METHODS: The SOS study (n = 4047) is a prospective controlled intervention study. The present analysis included 1989 patients treated with bariatric surgery and 2027 control patients with obesity who received usual care. Diagnosed hypoglycaemia and events commonly attributed to hypoglycaemia (confusion, syncope, epilepsy and seizures), requiring hospital or specialist outpatient treatment, were identified by searching the National Patient Register. Analyses were stratified by baseline glycaemic status. Hazard ratios were adjusted for inclusion year, age, sex, smoking, glycated haemoglobin (HbA1c) level and body mass index at baseline. At the time of analysis (December 31, 2018), the median follow-up was 22 years. RESULTS: Compared with usual care, bariatric surgery was associated with increased incidence of hypoglycaemia-related events in patients without baseline diabetes (168 and 219 events, respectively; log-rank P = .011), with a more pronounced risk during the first years of follow-up (test of time-treatment interaction P = .010). Multivariate analyses in patients without baseline diabetes indicated that male sex (P < .001), older age (P = .001) and higher HbA1c levels (P = .006) were associated with hypoglycaemia-related events. No association was found between risk of hypoglycaemia-related events and bariatric surgery in patients with baseline diabetes. CONCLUSIONS: Bariatric surgery is associated with an increased incidence of hypoglycaemia-related events in patients without baseline diabetes, especially during the first years after treatment.

Long-term incidence of colorectal cancer after bariatric surgery or usual care in the Swedish Obese Subjects study.

Bariatric surgery in patients with obesity is generally considered to reduce cancer risk in patients with obesity. However, for colorectal cancer some studies report an increased risk with bariatric surgery, whereas others report a decreased risk. These conflicting results demonstrate the need of more long-term studies analyzing the effect of bariatric surgery on colorectal cancer risk. Therefore, data from the Swedish Obese Subjects (SOS) study, ClinicalTrials.gov identifier: NCT01479452, was used to examine the impact of bariatric surgery on long-term incidence of colorectal cancer. The SOS study includes 2007 patients who underwent bariatric surgery and 2040 contemporaneously matched controls who received conventional obesity treatment. Patients in the surgery group underwent gastric bypass (n = 266), banding (n = 376) or vertical banded gastroplasty (n = 1365). Information on colorectal cancer events was obtained from the Swedish National Cancer Registry. Median follow-up was 22.2 years (inter-quartile range 18.3-25.2). During follow up there were 58 colorectal cancer events in the surgery group and 67 colorectal cancer events in the matched control group with a hazard ratio (HR) of 0.79 (95% CI:0.55-1.12; p = 0.183). After adjusting for age, body mass index, alcohol intake, smoking status, and diabetes, the adjusted HR was 0.89 (95% CI:0.62-1.29; p = 0.551). When analyzing rectal cancer events separately- 19 events in the surgery group and 31 events in the control group-a decreased risk of rectal cancer with surgery was observed (HR = 0.56; 95% CI:0.32-0.99; p = 0.045, adjusted HR = 0.61 (95% CI:0.34-1.10; p = 0.099), while the risk of colon cancer was unchanged. To conclude- in this long-term, prospective study, bariatric surgery was not associated with altered colorectal cancer risk.

Heart failure development in obesity: underlying risk factors and mechanistic pathways.

AIMS: People with obesity are at risk for developing heart failure (HF), but little is known about the mechanistic pathways that link obesity with cardiac dysfunction. METHODS AND RESULTS: We included 2030 participants from the Swedish Obese Subjects study who received conventional obesity treatment. First-time detection of HF was obtained by cross-checking the study population with the Swedish National Patient Register and the Swedish Cause of Death Register. We also examined if atrial fibrillation and myocardial infarction as time-dependent variables could predict incident HF The mean age of the study cohort was 48.7 years, and 28% were men. The mean body mass index at baseline was 40.1 kg/m2 and remained stable during a median follow-up of 20.1 years. First-time diagnosis of HF occurred in 266 of patients and was related to male sex, increasing age, greater waist-hip ratio, hypertension, higher cholesterol, diabetes mellitus, and elevated free thyroxine in univariable analysis. Estimated glomerular filtration rate was negatively related to HF risk. In multivariable analysis, atrial fibrillation, which is related to HF with preserved ejection fraction (HFpEF), and myocardial infarction, which is linked to HF with reduced ejection fraction (HFrEF), were strongly associated with incident HF with sub-hazard ratios 3.75 (95% confidence interval: 2.72-5.18, P < 0.001) and 3.68 (95% confidence interval: 2.55-5.30, P < 0.001), respectively. CONCLUSIONS: Both atrial fibrillation and myocardial infarction as time-dependent variables were independently and strongly related to incident HF in people with excess body fat, suggesting two main obesity-related mechanistic pathways leading to either HFpEF or HFrEF.

Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study.

BACKGROUND: Obesity shortens life expectancy. Bariatric surgery is known to reduce the long-term relative risk of death, but its effect on life expectancy is unclear. METHODS: We used the Gompertz proportional hazards regression model to compare mortality and life expectancy among patients treated with either bariatric surgery (surgery group) or usual obesity care (control group) in the prospective, controlled Swedish Obese Subjects (SOS) study and participants in the SOS reference study (reference cohort), a random sample from the general population. RESULTS: In total, 2007 and 2040 patients were included in the surgery group and the control group, respectively, and 1135 participants were included in the reference cohort. At the time of the analysis (December 31, 2018), the median duration of follow-up for mortality was 24 years (interquartile range, 22 to 27) in the surgery group and 22 years (interquartile range, 21 to 27) in the control group; data on mortality were available for 99.9% of patients in the study. In the SOS reference cohort, the median duration of follow-up was 20 years (interquartile range, 19 to 21), and data on mortality were available for 100% of participants. In total, 457 patients (22.8%) in the surgery group and 539 patients (26.4%) in the control group died (hazard ratio, 0.77; 95% confidence interval [CI], 0.68 to 0.87; P<0.001). The corresponding hazard ratio was 0.70 (95% CI, 0.57 to 0.85) for death from cardiovascular disease and 0.77 (95% CI, 0.61 to 0.96) for death from cancer. The adjusted median life expectancy in the surgery group was 3.0 years (95% CI, 1.8 to 4.2) longer than in the control group but 5.5 years shorter than in the general population. The 90-day postoperative mortality was 0.2%, and 2.9% of the patients in the surgery group underwent repeat surgery. CONCLUSIONS: Among patients with obesity, bariatric surgery was associated with longer life expectancy than usual obesity care. Mortality remained higher in both groups than in the general population. (Funded by the Swedish Research Council and others; SOS ClinicalTrials.gov number, NCT01479452.).

9p21.3 Coronary Artery Disease Locus Identifies Patients With Treatment Benefit From Bariatric Surgery in the Nonrandomized Prospective Controlled Swedish Obese Subjects Study.

BACKGROUND: Sequence variation at chromosome 9p21.3 accounts for 20% of myocardial infarctions (MIs) in several populations. Whereas the risk conferred by the 9p21.3 locus appears to act independently of traditional risk factors, studies suggest that the association between 9p21.3 and MI is modified by glucose homeostasis and lifestyle. We examined if the 9p21.3 variant rs1333049, along with the previously identified predictor fasting insulin, modifies the preventive effect of bariatric surgery on MI incidence. METHODS: rs1333049 was genotyped in 1852 patients treated by bariatric surgery and 1803 controls given usual care in the SOS study (Swedish Obese Subjects). MI incidence was determined using national registers. Median follow-up was 21 years (interquartile range 18-24 years). RESULTS: Overall, 366 MIs occurred during follow-up. Among rs1333049 risk-allele carriers (CC+GC), the incidence of MI was reduced in the surgery group compared with the control group (hazard ratio=0.72 [95% CI, 0.57-0.92], P=0.008). By contrast, noncarriers (GG) showed no significant differences in MI incidence between the treatment groups (hazard ratio=1.28 [0.86-1.90], P=0.227; interaction between treatment and the risk-allele P=0.016). In addition, carriers with higher fasting insulin (above the median [17 mmol/L]) experienced significantly higher MI incidence than carriers with lower fasting insulin (hazard ratio=0.58 [0.42-0.78], P<0.001, interaction P=0.031). CONCLUSIONS: In the SOS cohort, patients with the chromosome 9p21.3 rs1333049 risk allele together with high fasting insulin levels benefitted from bariatric surgery in terms of reduced incidence of MI. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01479452.

Evaluation of Prediction Models for Type 2 Diabetes Relapse After Post-bariatric Surgery Remission: a Post hoc Analysis of 15-Year Follow-up Data from the Swedish Obese Subjects (SOS) Study.

PURPOSE: Many patients achieve type 2 diabetes (T2D) remission after bariatric surgery, but relapse after post-surgery remission is common. Scoring models accurately predict remission up to 5 years after surgery but have not been tested for prediction of long-term T2D relapse. The aim of this work was to test the ability of prediction models and single predictors to identify patients at risk of long-term relapse (10-15 years) after post-surgery T2D remission. METHODS: We identified 222 individuals with T2D from the surgically treated group in the prospective Swedish Obese Subjects study, who were in remission at the 2-year follow-up and had data available for prediction of long-term T2D relapse. T2D remission/relapse was assessed after 10 and 15 years. Model performance (discrimination) was evaluated by the area under the receiver operating characteristic (AUROC) curves. RESULTS: Preoperative prediction of relapse using scores DiaRem, Ad-DiaRem, and DiaBetter and T2D duration alone was poor, as indicated by AUROC curves between 0.61-0.64 at 10 years and 0.62-0.66 at 15 years. Likewise, the 5y-Ad-DiaRem score, which includes early postoperative measures, resulted in AUROC curves of 0.65 and 0.70 for relapse at 10 and 15 years, respectively. Two-year weight change alone had higher discriminatory capacity than the 5y-Ad-DiaRem model at 10 years (AUROC = 0.70; p = 0.036) and similar capacity at 15 years (AUROC = 0.78; p = 0.188). CONCLUSIONS: Predictive performance of all tested models is low for T2D relapse. By contrast, a single measure of 2-year weight change after surgery was associated with relapse, supporting a key role for initial weight reduction in long-term T2D control.

Effects of Bariatric Surgery in Early- and Adult-Onset Obesity in the Prospective Controlled Swedish Obese Subjects Study.

OBJECTIVE: Bariatric surgery is an effective treatment for obesity, but it is unknown if outcomes differ between adults with early- versus adult-onset obesity. We investigated how obesity status at 20 years of age affects outcomes after bariatric surgery later in life. RESEARCH DESIGN AND METHODS: The Swedish Obese Subjects study is a prospective matched study performed at 25 surgical departments and 480 primary health care centers. Participants aged 37-60 years with BMI ≥34 kg/m2 (men) or ≥38 kg/m2 (women) were recruited between 1987 and 2001; 2,007 participants received bariatric surgery and 2,040 usual care. Self-reported body weight at 20 years of age was used to stratify patients into subgroups with normal BMI (<25 kg/m2), overweight (BMI 25-29.9 kg/m2), or obesity (BMI ≥30 kg/m2). Body weight, energy intake, and type 2 diabetes status were examined over 10 years, and incidence of cardiovascular and microvascular disease was determined over up to 26 years using data from health registers. RESULTS: There were small but statistically significant differences in reduction of body weight among the subgroups after bariatric surgery (interaction P = 0.032), with the largest reductions among those with obesity aged 20 years. Bariatric surgery increased type 2 diabetes remission (odds ratios 4.51, 4.90, and 5.58 in subgroups with normal BMI, overweight, or obesity at 20 years of age, respectively; interaction P = 0.951), reduced type 2 diabetes incidence (odds ratios 0.15, 0.13, and 0.15, respectively; interaction P = 0.972), and reduced microvascular complications independent of obesity status at 20 years of age (interaction P = 0.650). The association between bariatric surgery and cardiovascular disease was similar in the subgroups (interaction P = 0.674). Surgical complications were similar in the subgroups. CONCLUSIONS: The treatment benefits of bariatric surgery in adults are similar regardless of obesity status at 20 years of age.

Association of Bariatric Surgery With Skin Cancer Incidence in Adults With Obesity: A Nonrandomized Controlled Trial.

Importance: Obesity is a cancer risk factor, and bariatric surgery in patients with obesity is associated with reduced cancer risk. However, evidence of an association among obesity, bariatric surgery, and skin cancer, including melanoma, is limited. Objective: To investigate the association of bariatric surgery with skin cancer (squamous cell carcinoma and melanoma) and melanoma incidence. Design, Setting, and Participants: This nonrandomized controlled trial, the Swedish Obese Subjects (SOS) study, is ongoing at 25 surgical departments and 480 primary health care centers in Sweden and was designed to examine outcomes after bariatric surgery. The study included 2007 patients with obesity who underwent bariatric surgery and 2040 contemporaneously matched controls who received conventional obesity treatment. Patients were enrolled between September 1, 1987, and January 31, 2001. Data analysis was performed from June 29, 2018, to November 22, 2018. Interventions: Patients in the surgery group underwent gastric bypass (n = 266), banding (n = 376), or vertical banded gastroplasty (n = 1365). The control group (n = 2040) received the customary treatment for obesity at their primary health care centers. Main Outcomes and Measures: The SOS study was cross-linked to the Swedish National Cancer Registry, the Cause of Death Registry, and the Registry of the Total Population for data on cancer incidence, death, and emigration. Results: The study included 4047 participants (mean [SD] age, 47.9 [6.1] years; 2867 [70.8%] female). Information on cancer events was available for 4042 patients. The study found that bariatric surgery was associated with a markedly reduced risk of melanoma (adjusted subhazard ratio, 0.43; 95% CI, 0.21-0.87; P = .02; median follow-up, 18.1 years) and risk of skin cancer in general (adjusted subhazard ratio, 0.59; 95% CI, 0.35-0.99; P = .047). The skin cancer risk reduction was not associated with baseline body mass index or weight; insulin, glucose, lipid, and creatinine levels; diabetes; blood pressure; alcohol intake; or smoking. Conclusions and Relevance: The results of this study suggest that bariatric surgery in individuals with obesity is associated with a reduced risk of skin cancer, including melanoma. Trial Registration: ClinicalTrials.gov identifier: NCT01479452.

Reoperations After Bariatric Surgery in 26 Years of Follow-up of the Swedish Obese Subjects Study.

Importance: Bariatric surgery is an established treatment for obesity, but knowledge on the long-term incidence of revisional surgery is scarce. Objective: To determine the incidence and type of revisional surgery after bariatric surgery in 26 years of follow-up of participants in the Swedish Obese Subjects (SOS) study. Design, Setting, and Participants: The SOS study is a prospective nonrandomized controlled study comparing bariatric surgery (banding, vertical banded gastroplasty [VBG], and gastric bypass [GBP]) with usual care. The bariatric surgeries in the SOS study were conducted at 25 public surgical departments in Sweden. Men with body mass index values of 34 or higher and women with body mass indexes of 38 or higher were recruited to the surgery group of the SOS study between September 1, 1987, and January 31, 2001, and follow-up continued until December 31, 2014. Data analysis occurred from November 2016 to April 2018. Interventions: Banding, VBG, or GBP. Main Outcomes and Measures: Revisional surgeries, analyzed using data from questionnaires, hospital records, and the Swedish National Patient register through December 31, 2014. Results: A total of 2010 participants underwent surgery. The age range was 37 to 60 years. A total of 376 participants underwent banding (18.7%), while 1365 had VBG (67.9%) and 266 had GBP (13.2%). During a median follow-up of 19 years, 559 participants (27.8%) underwent first-time revisional surgery, including 354 conversions to other bariatric procedures (17.6%), 114 corrective surgeries (5.6%), and 91 reversals to normal anatomy (4.5%). Revisional surgeries (conversions, corrective surgery, and reversals) were common after banding (153 of 376 [40.7%]) and VBG (386 of 1365 [28.3%]) but relatively rare after GBP (20 of 266 [7.5%]). Patients who had banding and VBG primarily underwent conversions to GBP or reversals. Incidence of reversals was 5 times higher after banding than after VBG (40.7% vs 7.5%; unadjusted hazard ratio, 5.19 [95% CI, 3.43-7.87]; P < .001). Corrective surgeries were equally common irrespective of the index surgery (72 of 1365 patients who had VBG [5.3%]; 23 of 376 patients who had banding [6.1%]; 19 of 266 patients who had GBP [7.1%]). Revisional surgery indications, including inadequate weight loss, band-associated complications (migration, stenosis, and slippage), staple-line disruptions, and postsurgical morbidity, varied depending on index surgery subgroup. Most corrections occurred within the first 10 years, whereas conversions and reversals occurred over the entire follow-up period. Conclusions and Relevance: Corrective surgeries occur mainly within the first 10 years and with similar incidences across all 3 surgical subgroups, but indications varied. Conversions (mainly to GBP) and reversals occurred after many years and were most frequent after banding and VBG, reflecting a higher overall revisional surgery demand after these operations.

Long-term incidence of serious fall-related injuries after bariatric surgery in Swedish obese subjects.

Obesity increases risk of falling, but the effect of bariatric surgery on fall-related injuries is unknown. The aim of this study was therefore to study the association between bariatric surgery and long-term incidence of fall-related injuries in the prospective, controlled Swedish Obese Subjects study. At inclusion, body mass index was ≥ 34 kg/m2 in men and ≥38 kg/m2 in women. The surgery per-protocol group (n = 2007) underwent gastric bypass (n = 266), banding (n = 376), or vertical banded gastroplasty (n = 1365), and controls (n = 2040) received usual care. At the time of analysis (31 December 2013), median follow-up was 19 years (maximal 26 years). Fall-related injuries requiring hospital treatment were captured using data from the Swedish National Patient Register. During follow-up, there were 617 first-time fall-related injuries in the surgery group and 513 in the control group (adjusted hazard ratio 1.21, 95% CI, 1.07-1.36; P = 0.002). The incidence differed between treatment groups (P < 0.001, log-rank test) and was higher after gastric bypass than after usual care, banding and vertical banded gastroplasty (adjusted hazard ratio 0.50-0.52, P < 0.001 for all three comparisons). In conclusion, gastric bypass surgery was associated with increased risk of serious fall-related injury requiring hospital treatment.

Expression of GHR and Downstream Signaling Genes in Human Adipose Tissue-Relation to Obesity and Weight Change.

CONTEXT: GH is a strong regulator of metabolism. In obesity, both GH secretion and adipose tissue GHR gene expression are decreased. More detailed information on the regulation of GHR, STAT3/5, and downstream-regulated genes in human adipose tissue during diet-induced weight loss and weight gain is lacking. OBJECTIVE: The aim of the present study was to investigate the gene expression patterns of GHR and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway (JAK2, STAT3, STAT5A, and STAT5B) in human subcutaneous adipose tissue in relation to energy restriction and overfeeding. DESIGN, PATIENTS, AND INTERVENTIONS: Tissue distribution was analyzed in a data set generated by RNA sequencing containing information on global expression in human tissues. Subcutaneous adipose tissue or adipocyte gene expression (measured by DNA microarrays) was investigated in the following settings: (i) individuals with obesity vs individuals with normal weight; (ii) energy restriction; and (iii) overfeeding. RESULTS: GHR expression was decreased in subjects with obesity compared with subjects with normal weight (P < 0.001). It was increased in response to energy restriction and decreased in response to overfeeding (P = 0.015 and P = 0.030, respectively). STAT3 expression was increased in subjects with obesity (P < 0.001). It was decreased during energy restriction and increased during overfeeding (P = 0.004 and P = 0.006, respectively). STAT3-regulated genes showed an overall view of overexpression in obesity. CONCLUSIONS: The results of the present study have shown that GHR, STAT3, and STAT3-regulated genes are dynamically, and reciprocally, regulated at the tissue level in response to energy restriction and overfeeding, suggesting that GH signaling is perturbed in obesity.