Hans Lönroth

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.

Gut hormones as mediators of appetite and weight loss after roux-en-Y gastric bypass

Objective:To evaluate the physiologic importance of the satiety gut hormones. Background:Controversy surrounds the physiologic role of gut hormones in the control of appetite. Bariatric surgery remains the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. Methods:We correlated peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) changes within the first week after gastric bypass with changes in appetite. We also evaluated the gut hormone responses of patients with good or poor weight loss after gastric bypass. Finally, we inhibited the gut hormone responses in gastric bypass patients and then evaluated appetite and food intake. Results:Postprandial PYY and GLP-1 profiles start rising as early as 2 days after gastric bypass (P < 0.05). Changes in appetite are evident within days after gastric bypass surgery (P < 0.05), and unlike other operations, the reduced appetite continues. However, in patients with poor weight loss after gastric bypass associated with increased appetite, the postprandial PYY and GLP-1 responses are attenuated compared with patients with good weight loss (P < 0.05). Inhibiting gut hormone responses, including PYY and GLP-1 after gastric bypass, results in return of appetite and increased food intake (P < 0.05). Conclusion:The attenuated appetite after gastric bypass is associated with elevated PYY and GLP-1 concentrations, and appetite returns when the release of gut hormones is inhibited. The results suggest a role for gut hormones in the mechanism of weight loss after gastric bypass and may have implications for the treatment of obesity.

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.

Body composition, dietary intake, and energy expenditure after laparoscopic Roux-en-Y gastric bypass and laparoscopic vertical banded gastroplasty: a randomized clinical trial.

Objective:To assess body composition, eating pattern, and basal metabolic rate in patients undergoing obesity surgery in a randomized trial. Introduction:There is limited knowledge regarding how different bariatric surgical techniques function in terms of altering body composition, dietary intake, and basic metabolic rate. Methods:Non-superobese patients were randomized to laparoscopic Roux-en-Y gastric bypass (LGBP, n = 37) or laparoscopic vertical banded gastroplasty (LVBG, n = 46). Anthropometry, dual-energy x-ray absorptiometry (DEXA), computed tomography (CT), indirect calorimetry, and reported dietary intake were registered prior to and 1 year after surgery. Results:Follow-up rate was 97.6%. LGBP patients had significantly greater reduction of waist circumference and sagittal diameter compared with LVBG. DEXA demonstrated a larger reduction of body fat in all compartments after LGBP, especially at the trunk (P<0.001). CT demonstrated more reduction of the visceral fat (P=0.016). Patients were able to eat all types of food after LGBP, although about 30% claimed they avoided fats. LGBP patients decreased their proportion of dietary fat significantly more than those operated on with LVBG (P = 0.005), who consumed more sweet foods and avoided whole meat and vegetables. Lean tissue mass (LTM) was proportionally less reduced, especially in men, after LGBP. The decreases in BMR postoperatively reflected the lower body mass in a pattern that did not differ among the groups. Conclusion:LGBP patients demonstrated better outcomes compared with LVBG patients in terms of body composition. Energy expenditure developed as expected postoperatively. A “steering” away from fatty foods after LGBP may be an important mechanism of action in gastric bypass.

The transfer of basic skills learned in a laparoscopic simulator to the operating room

BackgroundThe aim of the study was to evaluate whether basic surgical skills achieved by training in LapSim, a computerbased laparoscopic simulator, could be transferred to the operating room.MethodsFor this study, 24 medical students undergoing courses in surgery were randomly assigned to train with LapSim or to serve as control subjects. After they had undergone simulator training 2 h per week for 5 weeks, their basic skills in laparoscopic surgery were assessed in a porcine model. The time to perform each task was measured, and four senior surgeons independently graded the overall performance on a 9-step differential rating scale.ResultsThe participants randomized to train with LapSim showed significantly better results for all tasks in both parts of the study than the untrained participants, according to the expert evaluation. Time consumption was accordingly lower in the training group in the control group.ConclusionsThe results show that basic skills achieved by systematic training with a laparoscopic simulator such as LapSim can be transferred to the operating room.

Randomized controlled trial of prophylactic chest physiotherapy in major abdominal surgery.

Introduction This randomized controlled study evaluated the clinical benefit and physiological effects of prophylactic chest physiotherapy in open major abdominal surgery.

Laparoscopic Gastric Bypass: Development of Technique, Respiratory Function, and Long-Term Outcome

Background: Roux-en-Y gastric bypass (RYGBP) is the preferred operation for the treatment of morbid obesity by many surgeons. Hereby we present the process by which laparoscopic RYGBP (LRYGBP) developed at our institution. Methods: Perioperative morbidity was recorded from 150 consecutive morbidly obese patients operated upon by RYGBP from August 1994 to March 2002. The first 76 consecutive patients have been followed up to 5 years postoperatively. A subgroup of 40 patients was recruited to evaluate the postoperative lung function in a randomized study between receiving and not receiving prophylactic chest physiotherapy. Results: In the whole series, there were 4 conversions to open surgery, 5 leaks, 12 postoperative bleedings and 1 intestinal obstruction. 1 patient succumbed after developing acute dilatation of the bypassed stomach. Respiratory function deteriorated significantly in all patients in the early postoperative period, irrespective if given physiotherapy. During the follow-up period, 3 patients developed mechanical obstruction of the Roux limb. Another patient had a perforated ulcer at the proximal pouch. Weight reduction averaged 70% of excess body weight at 2 years after surgery. Conclusions: LRYGBP is an effective treatment for morbid obesity. During the initial development, we experienced a number of serious complications. The complication rate decreased over time. Postoperative lung function was markedly impaired, but there were no beneficial effects of chest physiotherapy. Long-term weight loss after LRYGBP seems to be comparable to what has been reported after open RYGBP.

Pneumatic dilatation or laparoscopic cardiomyotomy in the management of newly diagnosed idiopathic achalasia. Results of a randomized controlled trial.

BackgroundThe most effective therapeutic strategy in newly diagnosed achalasia is yet to be established. Therefore we designed a study in which pneumatic dilatation was compared to laparoscopic cardiomyotomy to which was added a partial posterior fundoplication.Patients and ResultsA series of 51 patients (24 males, mean age 44 years) were randomly allocated to the therapeutic modalities (dilatation = 26, surgery = 25). All patients were followed for at least 12 months, and during that period the pneumatic dilatations strategy had significantly more treatment failures (P = 0.04). Only minor differences emerged between the study groups when symptoms, dysphagia scorings, and quality-of-life assessments were evaluated 12 months after initiation of therapy.ConclusionsLaparoscopic myotomy was found to be superior to an endoscopic balloon dilatation strategy in the treatment of achalasia when studied during the first 12 months after treatment.