Ingmar Näslund

Bariatric Surgery and Long-term Cardiovascular Events

CONTEXT Obesity is a risk factor for cardiovascular events. Weight loss might protect against cardiovascular events, but solid evidence is lacking. OBJECTIVE To study the association between bariatric surgery, weight loss, and cardiovascular events. DESIGN, SETTING, AND PARTICIPANTS The Swedish Obese Subjects (SOS) study is an ongoing, nonrandomized, prospective, controlled study conducted at 25 public surgical departments and 480 primary health care centers in Sweden of 2010 obese participants who underwent bariatric surgery and 2037 contemporaneously matched obese controls who received usual care. Patients were recruited between September 1, 1987, and January 31, 2001. Date of analysis was December 31, 2009, with median follow-up of 14.7 years (range, 0-20 years). Inclusion criteria were age 37 to 60 years and a body mass index of at least 34 in men and at least 38 in women. Exclusion criteria were identical in surgery and control patients. Surgery patients underwent gastric bypass (13.2%), banding (18.7%), or vertical banded gastroplasty (68.1%), and controls received usual care in the Swedish primary health care system. Physical and biochemical examinations and database cross-checks were undertaken at preplanned intervals. MAIN OUTCOME MEASURES The primary end point of the SOS study (total mortality) was published in 2007. Myocardial infarction and stroke were predefined secondary end points, considered separately and combined. RESULTS Bariatric surgery was associated with a reduced number of cardiovascular deaths (28 events among 2010 patients in the surgery group vs 49 events among 2037 patients in the control group; adjusted hazard ratio [HR], 0.47; 95% CI, 0.29-0.76; P = .002). The number of total first time (fatal or nonfatal) cardiovascular events (myocardial infarction or stroke, whichever came first) was lower in the surgery group (199 events among 2010 patients) than in the control group (234 events among 2037 patients; adjusted HR, 0.67; 95% CI, 0.54-0.83; P < .001). CONCLUSION Compared with usual care, bariatric surgery was associated with reduced number of cardiovascular deaths and lower incidence of cardiovascular events in obese adults.

Bariatric Surgery and Prevention of Type 2 Diabetes in Swedish Obese Subjects

BACKGROUND Weight loss protects against type 2 diabetes but is hard to maintain with behavioral modification alone. In an analysis of data from a nonrandomized, prospective, controlled study, we examined the effects of bariatric surgery on the prevention of type 2 diabetes. METHODS In this analysis, we included 1658 patients who underwent bariatric surgery and 1771 obese matched controls (with matching performed on a group, rather than individual, level). None of the participants had diabetes at baseline. Patients in the bariatric-surgery cohort underwent banding (19%), vertical banded gastroplasty (69%), or gastric bypass (12%); nonrandomized, matched, prospective controls received usual care. Participants were 37 to 60 years of age, and the body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) was 34 or more in men and 38 or more in women. This analysis focused on the rate of incident type 2 diabetes, which was a prespecified secondary end point in the main study. At the time of this analysis (January 1, 2012), participants had been followed for up to 15 years. Despite matching, some baseline characteristics differed significantly between the groups; the baseline body weight was higher and risk factors were more pronounced in the bariatric-surgery group than in the control group. At 15 years, 36.2% of the original participants had dropped out of the study, and 30.9% had not yet reached the time for their 15-year follow-up examination. RESULTS During the follow-up period, type 2 diabetes developed in 392 participants in the control group and in 110 in the bariatric-surgery group, corresponding to incidence rates of 28.4 cases per 1000 person-years and 6.8 cases per 1000 person-years, respectively (adjusted hazard ratio with bariatric surgery, 0.17; 95% confidence interval, 0.13 to 0.21; P<0.001). The effect of bariatric surgery was influenced by the presence or absence of impaired fasting glucose (P=0.002 for the interaction) but not by BMI (P=0.54). Sensitivity analyses, including end-point imputations, did not change the overall conclusions. The postoperative mortality was 0.2%, and 2.8% of patients who underwent bariatric surgery required reoperation within 90 days owing to complications. CONCLUSIONS Bariatric surgery appears to be markedly more efficient than usual care in the prevention of type 2 diabetes in obese persons. (Funded by the Swedish Research Council and others; ClinicalTrials.gov number, NCT01479452.).

Effects of bariatric surgery on cancer incidence in obese patients in Sweden (Swedish Obese Subjects Study): a prospective, controlled intervention trial

BACKGROUND Obesity is a risk factor for cancer. Intentional weight loss in the obese might protect against malignancy, but evidence is limited. To our knowledge, the Swedish Obese Subjects (SOS) study is the first intervention trial in the obese population to provide prospective, controlled cancer-incidence data. METHODS The SOS study started in 1987 and involved 2010 obese patients (body-mass index [BMI] >or=34 kg/m(2) in men, and >or=38 kg/m(2) in women) who underwent bariatric surgery and 2037 contemporaneously matched obese controls, who received conventional treatment. While the main endpoint of SOS was overall mortality, the main outcome of this exploratory report was cancer incidence until Dec 31, 2005. Cancer follow-up rate was 99.9% and the median follow-up time was 10.9 years (range 0-18.1 years). FINDINGS Bariatric surgery resulted in a sustained mean weight reduction of 19.9 kg (SD 15.6 kg) over 10 years, whereas the mean weight change in controls was a gain of 1.3 kg (SD 13.7 kg). The number of first-time cancers after inclusion was lower in the surgery group (n=117) than in the control group (n=169; HR 0.67, 95% CI 0.53-0.85, p=0.0009). The sex-treatment interaction p value was 0.054. In women, the number of first-time cancers after inclusion was lower in the surgery group (n=79) than in the control group (n=130; HR 0.58, 0.44-0.77; p=0.0001), whereas there was no effect of surgery in men (38 in the surgery group vs 39 in the control group; HR 0.97, 0.62-1.52; p=0.90). Similar results were obtained after exclusion of all cancer cases during the first 3 years of the intervention. INTERPRETATION Bariatric surgery was associated with reduced cancer incidence in obese women but not in obese men. FUNDING Swedish Research Council, Swedish Foundation for Strategic Research, Swedish Federal Government under the LUA/ALF agreement, Hoffmann La Roche, Cederoths, AstraZeneca, Sanofi-Aventis, Ethicon Endosurgery.

Association of bariatric surgery with long-term remission of type 2 diabetes and with microvascular and macrovascular complications.

IMPORTANCE Short-term studies show that bariatric surgery causes remission of diabetes. The long-term outcomes for remission and diabetes-related complications are not known. OBJECTIVES To determine the long-term diabetes remission rates and the cumulative incidence of microvascular and macrovascular diabetes complications after bariatric surgery. DESIGN, SETTING, AND PARTICIPANTS The Swedish Obese Subjects (SOS) is a prospective matched cohort study conducted at 25 surgical departments and 480 primary health care centers in Sweden. Of patients recruited between September 1, 1987, and January 31, 2001, 260 of 2037 control patients and 343 of 2010 surgery patients had type 2 diabetes at baseline. For the current analysis, diabetes status was determined at SOS health examinations until May 22, 2013. Information on diabetes complications was obtained from national health registers until December 31, 2012. Participation rates at the 2-, 10-, and 15-year examinations were 81%, 58%, and 41% in the control group and 90%, 76%, and 47% in the surgery group. For diabetes assessment, the median follow-up time was 10 years (interquartile range [IQR], 2-15) and 10 years (IQR, 10-15) in the control and surgery groups, respectively. For diabetes complications, the median follow-up time was 17.6 years (IQR, 14.2-19.8) and 18.1 years (IQR, 15.2-21.1) in the control and surgery groups, respectively. INTERVENTIONS Adjustable or nonadjustable banding (n = 61), vertical banded gastroplasty (n = 227), or gastric bypass (n = 55) procedures were performed in the surgery group, and usual obesity and diabetes care was provided to the control group. MAIN OUTCOMES AND MEASURES Diabetes remission, relapse, and diabetes complications. Remission was defined as blood glucose <110 mg/dL and no diabetes medication. RESULTS The diabetes remission rate 2 years after surgery was 16.4% (95% CI, 11.7%-22.2%; 34/207) for control patients and 72.3% (95% CI, 66.9%-77.2%; 219/303) for bariatric surgery patients (odds ratio [OR], 13.3; 95% CI, 8.5-20.7; P < .001). At 15 years, the diabetes remission rates decreased to 6.5% (4/62) for control patients and to 30.4% (35/115) for bariatric surgery patients (OR, 6.3; 95% CI, 2.1-18.9; P < .001). With long-term follow-up, the cumulative incidence of microvascular complications was 41.8 per 1000 person-years (95% CI, 35.3-49.5) for control patients and 20.6 per 1000 person-years (95% CI, 17.0-24.9) in the surgery group (hazard ratio [HR], 0.44; 95% CI, 0.34-0.56; P < .001). Macrovascular complications were observed in 44.2 per 1000 person-years (95% CI, 37.5-52.1) in control patients and 31.7 per 1000 person-years (95% CI, 27.0-37.2) for the surgical group (HR, 0.68; 95% CI, 0.54-0.85; P = .001). CONCLUSIONS AND RELEVANCE In this very long-term follow-up observational study of obese patients with type 2 diabetes, bariatric surgery was associated with more frequent diabetes remission and fewer complications than usual care. These findings require confirmation in randomized trials. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01479452.

Outcomes of Pregnancy after Bariatric Surgery

BACKGROUND Maternal obesity is associated with increased risks of gestational diabetes, large-for-gestational-age infants, preterm birth, congenital malformations, and stillbirth. The risks of these outcomes among women who have undergone bariatric surgery are unclear. METHODS We identified 627,693 singleton pregnancies in the Swedish Medical Birth Register from 2006 through 2011, of which 670 occurred in women who had previously undergone bariatric surgery and for whom presurgery weight was documented. For each pregnancy after bariatric surgery, up to five control pregnancies were matched for the mothers presurgery body-mass index (BMI; we used early-pregnancy BMI in the controls), age, parity, smoking history, educational level, and delivery year. We assessed the risks of gestational diabetes, large-for-gestational-age and small-for-gestational-age infants, preterm birth, stillbirth, neonatal death, and major congenital malformations. RESULTS Pregnancies after bariatric surgery, as compared with matched control pregnancies, were associated with lower risks of gestational diabetes (1.9% vs. 6.8%; odds ratio, 0.25; 95% confidence interval [CI], 0.13 to 0.47; P<0.001) and large-for-gestational-age infants (8.6% vs. 22.4%; odds ratio, 0.33; 95% CI, 0.24 to 0.44; P<0.001). In contrast, they were associated with a higher risk of small-for-gestational-age infants (15.6% vs. 7.6%; odds ratio, 2.20; 95% CI, 1.64 to 2.95; P<0.001) and shorter gestation (273.0 vs. 277.5 days; mean difference -4.5 days; 95% CI, -2.9 to -6.0; P<0.001), although the risk of preterm birth was not significantly different (10.0% vs. 7.5%; odds ratio, 1.28; 95% CI, 0.92 to 1.78; P=0.15). The risk of stillbirth or neonatal death was 1.7% versus 0.7% (odds ratio, 2.39; 95% CI, 0.98 to 5.85; P=0.06). There was no significant between-group difference in the frequency of congenital malformations. CONCLUSIONS Bariatric surgery was associated with reduced risks of gestational diabetes and excessive fetal growth, shorter gestation, an increased risk of small-for-gestational-age infants, and possibly increased mortality. (Funded by the Swedish Research Council and others.).

Gallstones, gallbladder disease, and pancreatitis: cross-sectional and 2-year data from the Swedish Obese Subjects (SOS) and SOS reference studies.

OBJECTIVES:Obesity and weight loss have been associated with gallstone disease. There is also an association between gallstones and pancreatitis. We investigated cross-sectional relationships between body mass index (BMI), body fat distribution, and prevalence of gallstones, gallbladder disease, and pancreatitis in men and women. Furthermore, 2-yr incidences of these disorders were examined in relation to changes in weight and body fat distribution after surgical and conventional obesity treatment.METHODS:Self-administered questionnaires were used to assess biliary and pancreatic disease. In the cross-sectional investigation, 6328 obese patients and 1135 randomly selected reference individuals were used. Longitudinally, 1422 operated and 1260 conventionally treated patients were examined.RESULTS:Obese subjects had significantly higher prevalence of cholelithiasis, cholecystitis, cholecystectomies, and pancreatitis as compared with the reference population. In women, BMI and waist–hip ratio (WHR) were independently related to an increased biliary disease prevalence. In men, only BMI was independently associated with biliary disease. Compared with conventional treatment, obesity surgery significantly increased the incidence of cholelithiasis, cholecystitis, and cholecystectomies in men. There was no incidence difference among women. In both genders, weight loss, but not change in WHR, was related to an increased incidence of biliary disease.CONCLUSIONS:This study showed an increased prevalence of gallstones, gallbladder disease, and pancreatitis in the obese. Biliary disease was related to BMI and WHR in women, but only to BMI in men. Weight loss, but not change in WHR, increased the risk of biliary disease in both genders.

Early Complications After Laparoscopic Gastric Bypass Surgery : Results From the Scandinavian Obesity Surgery Registry

Objective:To identify risk factors for serious and specific early complications of laparoscopic gastric bypass surgery using a large national cohort of patients. Background:Bariatric procedures are among the most common surgical procedures today. There is, however, still a need to identify preoperative and intraoperative risk factors for serious complications. Methods:From the Scandinavian Obesity Surgery Registry database, we identified 26,173 patients undergoing primary laparoscopic gastric bypass operation for morbid obesity between May 1, 2007, and September 30, 2012. Follow-up on day 30 was 95.7%. Preoperative data and data from the operation were analyzed against serious postoperative complications and specific complications. Results:The overall risk of serious postoperative complications was 3.4%. Age (adjusted P = 0.028), other additional operation [odds ratio (OR) = 1.50; confidence interval (CI): 1.04–2.18], intraoperative adverse event (OR = 2.63; 1.89–3.66), and conversion to open surgery (OR = 4.12; CI: 2.47–6.89) were all risk factors for serious postoperative complications. Annual hospital volume affected the rate of serious postoperative complications. If the hospital was in a learning curve at the time of the operation, the risk for serious postoperative complications was higher (OR = 1.45; CI: 1.22–1.71). The 90-day mortality rate was 0.04%. Conclusions:Intraoperative adverse events and conversion to open surgery are the strongest risk factors for serious complications after laparoscopic gastric bypass surgery. Annual operative volume and total institutional experience are important for the outcome. Patient related factors, in particular age, also increased the risk but to a lesser extent.

Long-term results 11 years after primary gastric bypass in 384 patients

BACKGROUND Roux-en-Y gastric bypass surgery (RYGB) as treatment of morbid obesity results in substantial weight loss. Most published long-term studies have included few patients at the last follow-up point. The aim of the present study was to explore long-term results in a large cohort of patients 7-17 years after gastric bypass. METHODS All 539 patients who had undergone primary RYGB from 1993 to 2003 at Uppsala and Örebro University Hospitals received a questionnaire regarding their postoperative status. Blood samples were obtained and the medical charts studied. RESULTS Of the 539 patients, 384 responded (71.2% response rate, mean age 37.9 yr, body mass index 44.5 kg/m(2) at surgery, 317 women, and 67 men). At a mean follow-up of 11.4 years (range 7-17), the body mass index had decreased to 32.5 kg/m(2), corresponding to an excess body mass index loss of 63.3%. Similar weight loss was observed, regardless of the length of follow-up. Orally treated diabetes resolved in 72% and sleep apnea and hyperlipidemia were improved. Revisional bariatric surgery had been performed in 2.1% and abdominoplasty in 40.2%. The gastrointestinal symptoms were considered tolerable. The overall result was satisfactory for 79% of the patients and 92% would recommend Roux-en-Y gastric bypass to a friend. Attendance to the annual checkups was 37%. Vitamin B12 supplements were taken by 72% and multivitamins by 24%. CONCLUSION At 11 years, substantial weight loss was maintained and revisional surgery was rare. Surprisingly few patients were compliant with the recommendation of lifelong supplements and yearly evaluations; however, patient satisfaction was high.

Alcohol consumption and alcohol problems after bariatric surgery in the swedish obese subjects study

Increased sensitivity to alcohol after gastric bypass has been described. The aim of this study was to investigate whether bariatric surgery is associated with alcohol problems.

Cardiovascular disease and mortality in patients with type 2 diabetes after bariatric surgery in Sweden: a nationwide, matched, observational cohort study

BACKGROUND In patients with diabetes and obesity specifically, no studies have examined mortality after bariatric surgery. We did a nationwide study in Sweden to examine risks of cardiovascular disease and mortality in patients with obesity and diabetes who had undergone bariatric surgery (Roux-en-Y gastric bypass [RYGB]). METHODS In this nationwide, matched, observational cohort study, we merged data for patients who had undergone RYGB registered in the Scandinavian Obesity Surgery Registry with other national databases, and identified matched controls (on the basis of sex, age, BMI, and calendar time [year]) who had not undergone bariatric surgery from the National Diabetes Registry. We assessed risks of cardiovascular disease and death using a Cox proportional-hazards regression model and other methods to examine the treatment effect while accounting for residual confounding. Primary outcomes were total mortality, cardiovascular death, and fatal or non-fatal myocardial infarction. FINDINGS Between Jan 1, 2007, and Dec 31, 2014, we obtained data for 6132 patients who had undergone RYGB and 6132 control patients who had not. Median follow-up was 3·5 years (IQR 2·1-4·7). We noted a 58% relative risk reduction (hazard ratio [HR] 0·42, 95% CI 0·30-0·57; p<0·0001) in overall mortality in the RYGB group compared with the controls. The risk of fatal or non-fatal myocardial infarction was 49% lower (HR 0·51, 0·29-0·91; p=0·021) and that of cardiovascular death was 59% lower (0·41, 0·19-0·90; p=0·026) in the RYGB group than in the control group. 5 year absolute risks of death were 1·8% (95% CI 1·5-2·2) in the RYGB group and 5·8% (5·0-6·8) in the control group. INTERPRETATION Our findings provide support for the benefits of RYGB surgery for patients with obesity and type 2 diabetes. The causes of these beneficial effects may be the weight reduction per se, changes in physiology and metabolism, improved care and treatment, improvements in lifestyle and risk factors, or combinations of these factors. FUNDING Swedish Association of Local Authorities and Regions and Region Västra Götaland.