Mortality in relation to diabetes remission in Swedish Obese Subjects -a prospective cohort study.

BACKGROUND: People with obesity and type 2 diabetes (T2D) have reduced life expectancy, partly explained by increased risk of cardiovascular diseases and cancer. Here, we examined whether 2-year diabetes remission after bariatric surgery or usual care is associated with long-term mortality. MATERIALS AND METHODS: This report includes 586 participants with obesity and concomitant T2D from the prospective Swedish Obese Subjects (SOS) cohort study; 338 underwent bariatric surgery and 248 received usual obesity care. At inclusion, age was 37-60 years and BMI ≥34 kg/m2 in men and ≥38 kg/m2 in women. Median follow-up was 26.2 years (interquartile range 22.7-28.7). Diabetes status was determined using self-reported data on diabetes medication and in-study measures of blood glucose and HbA1c. The study was cross-linked to Swedish national registers for data on morbidity, death, and emigration. RESULTS: Overall, 284 participants, 71.9% of surgery and 16.5% of usual care patients, were in remission at the 2-year examination. During follow-up, mortality rates were 16.6 deaths per 1000 person-years (95% CI:13.7-20.1) in the remission subgroup and 26.0 deaths per 1000 person-years (95% CI:22.2-30.4) in the non-remission subgroup (adjusted hazard ratio (HRadj)=0.71, 95% CI:0.54-0.95, P=0.019). The adjusted median life expectancy in the remission subgroup was 2.5 years (95% CI:0.3-4.7) longer than in the non-remission subgroup. Specifically, remission was associated with decreased cardiovascular mortality (sub-HRadj=0.54, 95% CI:0.35-0.85, P=0.008), but no detectable association with cancer mortality was found (sub-HRadj=1.06, 95% CI:0.60-1.86), P=0.841). CONCLUSION: In this post-hoc analysis of data from the SOS study, patients who achieved short-term diabetes remission had increased life expectancy and decreased cardiovascular death over up to 32 years of follow-up. Future studies should confirm these findings.

Fifteen-year changes in health-related quality of life after bariatric surgery and non-surgical obesity treatment.

BACKGROUND: Evidence on the long-term (≥10 years) development of health-related quality of life (HRQoL) following bariatric surgery is still limited and mainly based on small-scale studies. This study aimed to investigate (1) 15-year changes in mental, physical, social, and obesity-related HRQoL after bariatric surgery and non-surgical obesity treatment; and (2) whether sociodemographic factors and pre-operative health status are associated with 15-year HRQoL changes in the surgery group. METHODS: Participants were from the non-randomized, prospective, controlled Swedish Obese Subjects study. The surgery group (N = 2007, per-protocol) underwent gastric bypass, banding or vertical banded gastroplasty, and matched controls (N = 2040) received usual obesity care. Recruitment took place in 1987-2001 and measurements (including six HRQoL scales) were administered before treatment and after 0.5, 1, 2, 3, 4, 6, 8, 10 and 15 years. Multilevel mixed-effect regression models using all observations for estimation were conducted. RESULTS: Surgical patients experienced greater 15-year improvements in perceived health and overall mood, and greater reductions in depression, obesity-related problems, and social interaction limitations than controls (all p < 0.001, adjusted for baseline differences). Effect size (ES) was classified as large only for obesity-related problems (ES = 0.82). At the 15-year follow-up, surgical patients reported better perceived health (p < 0.001) and less obesity-related problems (p = 0.020) than controls. In the surgery group, patients with baseline diabetes had smaller 15-year reductions in social interaction limitations (p < 0.001) and depression (p = 0.049) compared to those without baseline diabetes. Although surgical patients with a history of psychiatric disorder reported lower HRQoL than those without such history over the 15-year follow-up, there were no significant differences in the long-term improvements between the two groups (p = 0.211-0.902). CONCLUSIONS: Over 15 years, surgical patients experienced more positive development of HRQoL compared to those receiving usual care. This difference was large for obesity-related problems, but otherwise the differences were small. Patients with pre-operative diabetes might be at increased risk for smaller long-term HRQoL improvements.

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.

Perceived Body Size in Relation to 10-Year Weight Change in the Swedish Obese Subjects Intervention Study.

INTRODUCTION: Body size underestimation in patients with obesity may be associated with long-term weight increase. In the current report, we analyse changes in body size perception in patients with obesity undergoing either bariatric surgery or usual obesity care, and in subgroups of patients who gain weight or maintain their body weight over 10 years. MATERIALS AND METHODS: A total of 2,504 patients with obesity from the prospective, controlled Swedish Obese Subjects (SOS) intervention study were included in this report, 1,370 patients underwent bariatric surgery and 1,134 patients were usual care controls. Weight was measured and body size was self-estimated using the Stunkard's figure rating scale at baseline and after 0.5, 1, 2, 3, 4, 6, 8 and 10 years of follow-up. A body perception index (BPI) was calculated as estimated/measured BMI. Weight (re)gain was defined as ≥10% increase between 1 and 10 years of follow-up. RESULTS: Body size was underestimated by 12% in the surgery and 14% in the control group (i.e., >5 BMI units) at baseline and underestimation largely persisted over 10 years in both intervention groups. When stratified by long-term weight development, weight regainers from the surgery group underestimated their body size to a larger degree compared to weight maintainers (12 vs. 9%, p < 0.001) after 10 years. Likewise weight gainers in the control group also underestimated their body size to a larger degree (17% vs. 13%, p < 0.001). In both groups, the change in BPI was significantly different between weight regainers and maintainers during follow-up (time-BPI interactions both p < 0.001). CONCLUSION: Patients with obesity underestimate their body size and this underestimation remains long-term even after major weight loss induced by bariatric surgery. In patients with obesity who maintain their weight, regardless of treatment, underestimation of body size persists but body size perception is slightly more accurate compared to patients who gain or regain weight long-term.

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.

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.

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.

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.

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.

Development of a BMI-Assigned Stunkard Scale for the Evaluation of Body Image Perception Based on Data of the SOS Reference Study.

INTRODUCTION: Stunkard's figure rating scale is a widely used tool to assess weight status and, more recently, body image perception in people with obesity. However, large population-based studies on Europeans linking this scale's silhouettes with measured BMI values are lacking. Therefore, we used measured weight and height data from the Swedish Obese Subjects (SOS) reference cohort to assign a mean BMI to each of the 9 Stunkard Scale silhouettes and to define silhouette cutoff values for categorizing people with obesity and overweight. METHODS: A total of 1,128 participants from the SOS reference cohort were included (54% females, BMI = 25.2 [ranging from 17.6 to 45.4] ±3.8 kg/m2, and age = 50 [ranging from 36 to 62] ±7 years [means ± standard deviation]). Patients estimated their own body size by choosing a silhouette of the Stunkard Scale. A mean BMI, based on measured weight and height, was assigned to each male and female silhouette of the Stunkard Scale. Measured BMI values were compared with BMI values calculated by simple linear regression analysis. ROC analysis was used to test accuracy of discrimination and the Youden index to assess optimal cutoff. RESULTS: Figure ratings and BMI were strongly correlated in men, r (518) = 0.76, p < 0.001 and women, r (606) = 0.80, p < 0.001. Silhouette selection significantly predicted BMI values in men, ß = 16.03, t (518) = 25.30, p < 0.001, and women, ß = 12.06, t (606) = 32.98, p < 0.001, and explained a significant proportion of variance in BMI values in men, R2 = 0.55, F (1, 518) = 639.98, p < 0.001, and women, R2 = 0.64, F (1, 606) = 1,087.88, p < 0.001. ROC curve analyses resulted in an optimal cutoff value of 6 for identifying people with obesity and 5 for overweight. CONCLUSION: Stunkard's figure rating scale can be used with confidence to assess weight status. Silhouette selection accurately classifies subjects as overweight or obese.

Long-term risk of anaemia after bariatric surgery: results from the Swedish Obese Subjects study.

BACKGROUND: Nutritional deficiencies, such as iron and vitamin B12 deficiencies, are potential adverse consequences of bariatric surgery. Long-term data on anaemia after bariatric surgery are largely lacking. We aimed to investigate the risk of anaemia, iron and vitamin B12 deficiency anaemia, and vitamin B12 deficiency over 20 years in individuals who had bariatric surgery or received usual obesity care. METHODS: The prospective, controlled Swedish Obese Subjects study recruited people with obesity via recruitment campaigns in the mass media and at primary health-care centres, and was done at 480 primary health-care centres and in 25 surgical departments in Sweden. Eligible participants were aged 37-60 years and had a BMI of either 34 kg/m2 or more (for men) or 38 kg/m2 or more (for women). Participants were excluded if they had undergone previous bariatric surgery or had contraindicating conditions. Two main groups were formed: those who chose bariatric surgery, the type of which was determined by the operating surgeon, and a contemporaneously matched control group, created by use of 18 matching variables, who received usual non-surgical obesity care that ranged from lifestyle advice to no treatment. Haemoglobin concentration was measured during examination visits at baseline and at 1 year, 2 years, 3 years, 4 years, 6 years, 8 years, 10 years, 15 years, and 20 years of follow-up. Anaemia was defined as a haemoglobin concentration of less than 120 g/L for women and 130 g/L for men. The primary, non-specified outcome was the incidence of anaemia, and was assessed in the as-treated population, which comprised only patients who received the actual treatment. The associations between treatment type and anaemia are expressed as unadjusted hazard ratios (HRs) and HRs adjusted for age, sex, BMI, menopausal status, education, diabetes, and hypertension, with 95% CIs. This study is registered in ClinicalTrials.gov, NCT01479452, and is closed to new participants, with follow-up ongoing. FINDINGS: Between Sept 1, 1987, and Jan 31, 2001, 6905 individuals were assessed for eligibility, of whom 5335 were eligible. Of these, we included 2007 patients who chose bariatric surgery (266 in the gastric bypass group, 1365 in the vertical-banded gastroplasty group, and 376 in the gastric banding group) and 2040 matched controls who received usual obesity care. During a maximum of 20 years and a median of 10 years (IQR 3-20) of follow-up, there were 133 anaemia events in the gastric bypass group, 359 in the vertical-banded gastroplasty group, 101 in the gastric banding group, and 261 in the control group. Compared with the control group (13 cases per 1000 person-years, 95% CI 11-14), the incidence of anaemia was higher in the gastric bypass group (64 cases per 1000 person-years, 53-74; HR 5·05, 95% CI 3·94-6·48; p<0·0001), the vertical-banded gastroplasty group (23 cases per 1000 person-years, 21-26; 2·67, 2·25-3·18; p<0·0001), and the gastric banding group (26 per 1000 person-years, 21-31; 2·76, 2·15-3·52; p<0·0001). These associations remained after adjustment. INTERPRETATION: Our findings highlight the increased risk of anaemia after bariatric surgery and the importance of long-term compliance to nutritional supplementation and monitoring to enable prevention and early detection of serious nutritional deficiencies after bariatric surgery. FUNDING: Swedish Research Council, the Swedish state under the agreement between the Swedish Government and the county councils, the Swedish Diabetes Foundation, the Swedish Heart-Lung Foundation, and the Novo Nordisk Foundation.

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.

Prediction of Suicide and Nonfatal Self-harm After Bariatric Surgery: A Risk Score Based on Sociodemographic Factors, Lifestyle Behavior, and Mental Health: A Nonrandomized Controlled Trial.

OBJECTIVE: To identify preoperative sociodemographic and health-related factors that predict higher risk of nonfatal self-harm and suicide after bariatric surgery. BACKGROUND: Evidence is emerging that bariatric surgery is related to an increased risk of suicide and self-harm, but knowledge on whether certain preoperative characteristics further enhance the excess risk is scarce. METHODS: The nonrandomized, prospective, controlled Swedish Obese Subjects study was linked to 2 Nationwide Swedish registers. The bariatric surgery group (N = 2007, per-protocol) underwent gastric bypass, banding or vertical banded gastroplasty, and matched controls (N = 2040) received usual care. Participants were recruited from 1987 to 2001, and information on the outcome (a death by suicide or nonfatal self-harm event) was retrieved until the end of 2016. Subhazard ratios (sub-HR) were calculated using competing risk regression analysis. RESULTS: The risk for self-harm/suicide was almost twice as high in surgical patients compared to control patients both before and after adjusting for various baseline factors [adjusted sub-HR = 1.98, 95% confidence interval (CI) = 1.34-2.93]. Male sex, previous healthcare visits for self-harm or mental disorders, psychiatric drug use, and sleep difficulties predicted higher risk of self-harm/suicide in the multivariate models conducted in the surgery group. Interaction tests further indicated that the excess risk for self-harm/suicide related to bariatric surgery was stronger in men (sub-HR = 3.31, 95% CI = 1.73-6.31) than in women (sub-HR = 1.54, 95% CI = 1.02-2.32) (P = 0.007 for adjusted interaction). A simple-to-use score was developed to identify those at highest risk of these events in the surgery group. CONCLUSIONS: Our findings suggest that male sex, psychiatric disorder history, and sleep difficulties are important predictors for nonfatal self-harm and suicide in postbariatric patients. High-risk patients who undergo surgery might require regular postoperative psychosocial monitoring to reduce the risk for future self-harm behaviors.

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.