| 1. |
- Backman, Olof, et al.
(författare)
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Gastric Bypass Surgery Reduces De Novo Cases of Type 2 Diabetes to Population Levels : A Nationwide Cohort Study From Sweden
- 2019
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Ingår i: Annals of Surgery. - : Lippincott Williams & Wilkins. - 0003-4932 .- 1528-1140. ; 269:5, s. 895-902
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to determine long-term changes in pharmacological treatment of type 2 diabetes after primary Roux-en-Y gastric bypass (RYGB) surgery, in patients with and without pharmacological treatment of diabetes preoperatively.SUMMARY OF BACKGROUND DATA: Several studies have shown that gastric bypass has good effect on diabetes, at least in the short-term. This study is a nationwide cohort study using Swedish registers, with basically no patients lost to follow-up during up to 7 years after surgery.METHODS: The effect of RYGB on type 2 diabetes drug treatment was evaluated in this nationwide matched cohort study. Participants were 22,047 adults with BMI ≥30 identified in the nationwide Scandinavian Surgical Obesity Registry, who underwent primary RYGB between 2007 and 2012. For each individual, up to 10 general population comparators were matched on birth year, sex, and place of residence. Prescription data were retrieved from the nationwide Swedish Prescribed Drug Register through September 2015. Incident use of pharmacological treatment was analyzed using Cox regression.RESULTS: Sixty-seven percent of patients with pharmacological treatment of type 2 diabetes before surgery were not using diabetes drugs 2 years after surgery and 61% of patients were not pharmacologically treated up to 7 years after surgery. In patients not using diabetes drugs at baseline, there were 189 new cases of pharmacological treatment of type 2 diabetes in the surgery group and 2319 in the matched general population comparators during a median follow-up of 4.6 years (incidence: 21.4 vs 27.9 per 10,000 person-years; adjusted hazard ratio 0.77, 95% confidence interval 0.67-0.89; P < 0.001).CONCLUSIONS: Gastric bypass surgery not only induces remission of pharmacological treatment of type 2 diabetes but also protects from new onset of pharmacological diabetes treatment. The effect seems to persist in most, but not all, patients over 7 years of follow-up.
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| 2. |
- Cao, Yang, Associate Professor, 1972-, et al.
(författare)
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A Comparative Study of Machine Learning Algorithms in Predicting Severe Complications after Bariatric Surgery
- 2019
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe obesity is a global public health threat of growing proportions. Accurate models to predict severe postoperative complications could be of value in the preoperative assessment of potential candidates for bariatric surgery. So far, traditional statistical methods have failed to produce high accuracy. We aimed to find a useful machine learning (ML) algorithm to predict the risk for severe complication after bariatric surgery.Methods: We trained and compared 29 supervised ML algorithms using information from 37,811 patients that operated with a bariatric surgical procedure between 2010 and 2014 in Sweden. The algorithms were then tested on 6250 patients operated in 2015. We performed the synthetic minority oversampling technique tackling the issue that only 3% of patients experienced severe complications.Results: Most of the ML algorithms showed high accuracy (>90%) and specificity (>90%) in both the training and test data. However, none of the algorithms achieved an acceptable sensitivity in the test data. We also tried to tune the hyperparameters of the algorithms to maximize sensitivity, but did not yet identify one with a high enough sensitivity that can be used in clinical praxis in bariatric surgery. However, a minor, but perceptible, improvement in deep neural network (NN) ML was found.Conclusion: In predicting the severe postoperative complication among the bariatric surgery patients, ensemble algorithms outperform base algorithms. When compared to other ML algorithms, deep NN has the potential to improve the accuracy and it deserves further investigation. The oversampling technique should be considered in the context of imbalanced data where the number of the interested outcome is relatively small.
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| 3. |
- Cao, Yang, Associate Professor, 1972-, et al.
(författare)
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Predicting Long-Term Health-Related Quality of Life after Bariatric Surgery Using a Conventional Neural Network : A Study Based on the Scandinavian Obesity Surgery Registry
- 2019
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Severe obesity has been associated with numerous comorbidities and reduced health-related quality of life (HRQoL). Although many studies have reported changes in HRQoL after bariatric surgery, few were long-term prospective studies. We examined the performance of the convolution neural network (CNN) for predicting 5-year HRQoL after bariatric surgery based on the available preoperative information from the Scandinavian Obesity Surgery Registry (SOReg). CNN was used to predict the 5-year HRQoL after bariatric surgery in a training dataset and evaluated in a test dataset. In general, performance of the CNN model (measured as mean squared error, MSE) increased with more convolution layer filters, computation units, and epochs, and decreased with a larger batch size. The CNN model showed an overwhelming advantage in predicting all the HRQoL measures. The MSEs of the CNN model for training data were 8% to 80% smaller than those of the linear regression model. When the models were evaluated using the test data, the CNN model performed better than the linear regression model. However, the issue of overfitting was apparent in the CNN model. We concluded that the performance of the CNN is better than the traditional multivariate linear regression model in predicting long-term HRQoL after bariatric surgery; however, the overfitting issue needs to be mitigated using more features or more patients to train the model.
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| 4. |
- Granstam, Elisabet, et al.
(författare)
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Gastric bypass surgery reduced the risk for diabetic retinopathy in patients with type 2 diabetes : A nationwide observational study
- 2019
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Konferensbidrag (refereegranskat)abstract
- Purpose: Diverging results have been reported with regards to the occurrence and progression of diabetic retinopathy following gastric bypass surgery (GBP) in patients with diabetes. We aimed to investigate the incidence of diabetic ocular complications in a nationwide study in Sweden in obese patients with type 2 diabetes mellitus (T2DM) following GBP and compared to a matched cohort of patients with T2DM not subjected to GBP surgery.Setting: Nationwide registry study in Sweden.Methods: We used data from two nationwide registers in Sweden: the Scandinavian Obesity Surgery Registry (SOReg) and the National Diabetes Registry (NDR). Patients with T2DM who had undergone GBP 2007-2013 reported to the SOReg were matched (1:1) with patients with T2DM from the NDR who had not had GBP surgery for obesity, based on sex, age, body mass index (BMI) and calender time (year). Follow-up data were obtained until December 31, 2015. The main outcome was occurrence of new diabetic retinopathy and was assessed with Cox proportional-hazards regression model. The importance of potential risk factors was assessed using a machine learning approach.Results: The study population consisted of 5321 patients who had undergone GBP and 5321 matched controls in NDR, and was followed up for a mean of 4.5 years. Mean age was 49.0 (SD 9.5) in the GBP and 47.1 (11.5) years in the control patients, respectively. BMI and HbA1c at baseline were 42.0 (5.7) and 60.0 (16.8) in the GBP group and 40.9 (7.3) kg/m2 and 58.5 (16.9) mmol/mol in the control group. Duration of diabetes was approximately 6 years in both groups. The risk for new diabetic retinopathy was reduced in the GBP patients (hazard ratio [HR] 0·62, 95% CI 0·49–0·78; p<0.001). The most important risk factors for development of diabetic retinopathy were diabetes duration, HbA1c, glomerular filtration rate (GFR), use of insulin and BMI. There was no evidence of increased risk for development of sight-threatening or treatment-requiring diabetic ocular complications such as diabetic macular edema, proliferative diabetic retinopathy, need for intravitreal drug administration, panretinal photocoagulation or vitrectomy.Conclusions: In this nationwide large cohort study of patients with type 2 diabetes we found a beneficial effect of GBP surgery on the risk for development of diabetic retinopathy. Furthermore, there were no indications for increased occurrence of sight-threatening or treatment-requiring diabetic retinopathy. These data provide support that, besides standard screening for diabetic retinopathy, there is no need for extended ophthalmological surveillance of patients with type 2 diabetes undergoing GBP surgery.
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| 5. |
- Hedberg, Suzanne, et al.
(författare)
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BEST: Bypass equipoise sleeve trial; rationale and design of a randomized, registry-based, multicenter trial comparing Roux-en-Y gastric bypass with sleeve gastrectomy
- 2019
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Ingår i: Contemporary Clinical Trials. - : Elsevier BV. - 1551-7144 .- 1559-2030. ; 84
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Tidskriftsartikel (refereegranskat)abstract
- Background: Laparoscopic gastric bypass (LGBP) is a well-documented surgical intervention for severe obesity. Recently, laparoscopic sleeve gastrectomy (LSG) has gained increased popularity. Short-term follow-up in limited-sized randomized trials comparing LGBP and LSG show no major differences in weight-loss, adverse events, or effect on comorbidities; however, there is a lack of sufficiently powered, pragmatic, randomized controlled trials comparing the mid- and long-term results of the two methods. Method: BEST is a randomized, registry-based, multicenter trial comparing LGBP and LSG. The trial has two primary outcomes; rates of substantial complications (SC) and total body weight loss. We hypothesize that patients treated with LSG will experience 35% fewer substantial complications during the 5-year follow-up compared to patients treated with LGBP, and that the efficacy of LSG will remain within a non-inferiority margin of 5% in terms of weight loss. Our sample size calculation, using data from the Scandinavian Obesity Surgery Registry (SOReg), shows a power of 80% for SC and > 95% for weight loss at p < .025 with a total of 2100 included patients. The design of the trial will also enable comparisons within several relevant patient subgroups. Conclusions: As a large-sized, pragmatic, randomized trial, BEST will provide robust data comparing LGBP with LSG by generating long-term results on weight loss and SC's, as well as secondary outcomes and comparisons within patient subgroups. The use of a well-established registry for registration of all data facilitates a large multicenter trial, and combines the strengths of registry studies with those of a randomized trial. Clinical Trials registry: NCT 02767505. © 2019 Elsevier Inc.
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| 6. |
- Jans, Anders, et al.
(författare)
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Duration of type 2 diabetes and remission rates after bariatric surgery in Sweden 2007-2015 : A registry-based cohort study
- 2019
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Ingår i: PLoS Medicine. - : Public Library of Science. - 1549-1277 .- 1549-1676. ; 16:11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although bariatric surgery is an effective treatment for type 2 diabetes (T2D) in patients with morbid obesity, further studies are needed to evaluate factors influencing the chance of achieving diabetes remission. The objective of the present study was to investigate the association between T2D duration and the chance of achieving remission of T2D after bariatric surgery.METHODS AND FINDINGS: We conducted a nationwide register-based cohort study including all adult patients with T2D and BMI ≥ 35 kg/m2 who received primary bariatric surgery in Sweden between 2007 and 2015 identified through the Scandinavian Obesity Surgery Registry. The main outcome was remission of T2D, defined as being free from diabetes medication or as complete remission (HbA1c < 42 mmol/mol without medication). In all, 8,546 patients with T2D were included. Mean age was 47.8 ± 10.1 years, mean BMI was 42.2 ± 5.8 kg/m2, 5,277 (61.7%) were women, and mean HbA1c was 58.9 ± 17.4 mmol/mol. The proportion of patients free from diabetes medication 2 years after surgery was 76.6% (n = 6,499), and 69.9% at 5 years (n = 3,765). The chance of being free from T2D medication was less in patients with longer preoperative duration of diabetes both at 2 years (odds ratio [OR] 0.80/year, 95% CI 0.79-0.81, p < 0.001) and 5 years after surgery (OR 0.76/year, 95% CI 0.75-0.78, p < 0.001). Complete remission of T2D was achieved in 58.2% (n = 2,090) at 2 years, and 46.6% at 5 years (n = 681). The chance of achieving complete remission correlated negatively with the duration of diabetes (adjusted OR 0.87/year, 95% CI 0.85-0.89, p < 0.001), insulin treatment (adjusted OR 0.25, 95% CI 0.20-0.31, p < 0.001), age (adjusted OR 0.94/year, 95% CI 0.93-0.95, p < 0.001), and HbA1c at baseline (adjusted OR 0.98/mmol/mol, 95% CI 0.97-0.98, p < 0.001), but was greater among males (adjusted OR 1.57, 95% CI 1.29-1.90, p < 0.001) and patients with higher BMI at baseline (adjusted OR 1.07/kg/m2, 95% CI 1.05-1.09, p < 0.001). The main limitations of the study lie in its retrospective nature and the low availability of HbA1c values at long-term follow-up.CONCLUSIONS: In this study, we found that remission of T2D after bariatric surgery was inversely associated with duration of diabetes and was highest among patients with recent onset and those without insulin treatment.
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| 7. |
- Liakopoulos, Vasileios, et al.
(författare)
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Pros and cons of gastric bypass surgery in individuals with obesity and type 2 diabetes: Nationwide, matched, observational cohort study
- 2019
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- © Author(s) (or their employer(s)) 2019. Objectives: Long-term effects of gastric bypass (GBP) surgery have been presented in observational and randomised studies, but there are only limited data for persons with obesity and type 2 diabetes mellitus (T2DM) regarding postoperative complications. Design: This is a nationwide observational study based on two quality registers in Sweden (National Diabetes Register, NDR and Scandinavian Obesity Surgery Register, SOReg) and other national databases. Setting: After merging the data, we matched individuals with T2DM who had undergone GBP with those not surgically treated for obesity on propensity score, based on sex, age, body mass index (BMI) and calendar time. The risks of postoperative outcomes (rehospitalisations) were assessed using Cox regression models. Participants: We identified 5321 patients with T2DM in the SOReg and 5321 matched controls in the NDR, aged 18-65 years, with BMI >27.5 kg/m 2 ; and followed for up to 9 years. Primary and secondary outcome measures: We assessed risks for all-cause mortality and hospitalisations for cardiovascular disease, severe kidney disease, along with surgical and other medical conditions. Results: The results agree with the previously suggested lower risks of all-cause mortality (49%) and cardiovascular disease (34%), and we also found positive effects for severe kidney disease but significantly increased risks (twofold to ninefold) of several short-term complications after GBP, such as abdominal pain and gastrointestinal conditions, frequently requiring surgical procedures, apart from reconstructive plastic surgery. Long-term, the risk of anaemia was 92% higher, malnutrition developed approximately three times as often, psychiatric diagnoses were 33% more frequent and alcohol abuse was three times as great as in the control group. Conclusions: This nationwide study confirms the benefits and describes the panorama of adverse events after bariatric surgery in persons with obesity and T2DM. Long-term postoperative monitoring and support, as better selection of patients by appropriate specialists in interdisciplinary settings, should be provided to optimise the outcomes.
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| 8. |
- Lundvall, Emma, et al.
(författare)
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The influence of staple height on postoperative complication rates after laparoscopic gastric bypass surgery using linear staplers
- 2019
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Ingår i: Surgery for Obesity and Related Diseases. - : Elsevier. - 1550-7289 .- 1878-7533. ; 15:3, s. 404-408
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Tidskriftsartikel (refereegranskat)abstract
- Background: The use of circular staplers with a low staple height is associated with a lower risk for complication when used to construct the gastroenterostomy in laparoscopic gastric bypass surgery. The influence of staple height on outcome when using linear staplers has not been studied.Objectives: To investigate the influence of staple height when constructing the gastric pouch and gastroenterostomy using a linear stapler in laparoscopic gastric bypass surgery.Setting: Nationwide, Sweden.Methods: A retrospective, register-based cohort study, including all primary laparoscopic gastric bypass surgical procedures in Sweden registered in the Scandinavian Obesity Surgery Registry from January 2010 until January 2017, where linear staplers were used to construct the gastric pouch and the gastroenterostomy. Low stapler heights (closed height <= 1.0 mm) were compared with higher stapler heights (closed height >= 1.5 mm). The main outcome was postoperative complication within 30 days of surgery.Results: Within the study period, 27,975 patients were identified from the Scandinavian Obesity Surgery Registry. A closed staple height >= 1.5 mm was associated with higher risk for postoperative complication within 30 days of surgery compared with lower staple height. The risk was greater when used to construct the gastric pouch (adjusted odd ratio 1.30, 95% confidence interval 1.17-1.44, P < .001) as well as when constructing the gastroenterostomy (adjusted odd ratio 1.32, 95% confidence interval 1.20-1.45, P < .001).Conclusion: The use of low staple height for construction of the gastric pouch and gastroenterostomy in laparoscopic gastric bypass surgery was associated with lower complication rates. (C) 2019 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
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| 9. |
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| 10. |
- Stenberg, Erik, 1979-, et al.
(författare)
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Comparing Techniques for Mesenteric Defects Closure in Laparoscopic Gastric Bypass Surgery : a Register-Based Cohort Study
- 2019
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Ingår i: Obesity Surgery. - : Springer Science+Business Media B.V.. - 0960-8923 .- 1708-0428. ; 29:4, s. 1229-1235
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Routine closure of mesenteric defects is generally considered standard part of laparoscopic gastric bypass surgery today. Controversy still exists regarding the optimal method for mesenteric defects closure. The objective was to compare different methods for mesenteric defects handling in laparoscopic gastric bypass surgery.METHODS: Primary laparoscopic gastric bypass procedures from 2010 until 2015 reported to the Scandinavian Obesity Surgery Registry (SOReg), where the mesenteric defects closure method was identifiable, were included. Main outcome measures were serious postoperative complication within 30 days after surgery, and reoperation for small bowel obstruction within 5 years after surgery. Quality-of-life before and after surgery, duration of surgery, and risk factors for complication were also analyzed. Information on operation for small bowel obstruction was based on data from the SOReg, the Swedish National Patient Register and reviews of hospital charts.RESULTS: In all, 34,707 patients were included. Serious postoperative complication occurred in 174 (2.9%) patients with sutures, in 592 (3.1%, adjusted p = 0.079) with clips, and 278 (3.1%; adjusted p = 0.658) in the non-closure group. Reoperation for small bowel obstruction within 5 years after surgery was lower with sutures (cumulative incidence 6.9%) and clips (cumulative incidence 7.3%; adjusted HR 1.16, 95% CI 1.02-1.32, p = 0.026), compared to non-closure (cumulative incidence 11.2%; adjusted HR 1.63, 95% CI 1.44-1.84, p < 0.0001).CONCLUSION: Closure of the mesenteric defects using either non-absorbable metal clips or non-absorbable running sutures is a safe and effective measure to reduce the risk for small bowel obstruction after laparoscopic gastric bypass surgery. Sutures appear slightly more effective and should remain gold standard for mesenteric defects closure.
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