Welcome to our weekly round-up of the latest bariatric and obesity-related papers published in the medical literature. As ever, we have looked far and wide to give you an overview of papers including a model predicting serious complication risks after bariatric surgery, a single centre study that found semaglutide was associated with weight loss similar to that seen in randomised clinical trials, ICG testing to determine risk for leakage, Barrett’s esophagus after RYGB, the impact of bariatric surgery on renal function, and a study that reported orlistat and acarbose can be successfully combined to provide efficacious weight loss (please note, log-in maybe required to access the full paper).
Predicting serious complication risks after bariatric surgery External validation of the MBSC risk prediction model using the DATO
Researchers from the Netherlands have reported that Dutch Audit for Treatment of Obesity (DATO) prediction model that provides information on complication risks for different types of bariatric surgery, has a good calibration but moderate discrimination.
Writing in SOARD, they stated that external validation is imperative to ensure the generalisability of predictions in a new patient population. Therefore, they performed an external validation of the risk prediction model for serious complications from the Michigan Bariatric Surgery Collaborative (MBSC) for Dutch bariatric patients using DATO.
All patients registered in the DATO undergoing bariatric surgery between 2015 and 2020 were included as the validation cohort. Serious complications included, among others, abdominal abscess, bowel obstruction, leak, and bleeding. Three risk prediction models were validated: 1) the original MBSC model from 2011; 2) the original MBSC model including the same variables but updated to more recent patients (2015-2020); 3) the current MBSC model. The following predictors from the MBSC model were available in the DATO: age, sex, procedure type, cardiovascular disease, and pulmonary disease.
They found that DATO validation cohort included 51,291 patients. Overall, 986 (1.92%) patients experienced serious complications. The original MBSC model, which was extended with the predictors 'GERD (yes/no),' OSAS (yes/no),' hypertension (yes/no), and renal disease (yes/no),' showed the best validation results. This model had a good calibration and AUC of 0.602, compared with an AUC of 0.65 and moderate-good calibration in the Michigan model.
“To be used in clinical practice, good calibration is essential to accurately predict individual risks in a real-world setting,” they concluded. “Therefore, this model could provide valuable information for bariatric surgeons as part of shared decision-making in daily practice.”
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Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity
US investigators have reported that semaglutide treatment in a regular clinical setting was associated with weight loss similar to that seen in randomized clinical trials, suggesting its applicability for treating patients with overweight or obesity.
This cohort study was conducted at a referral centre for weight management, retrospectively collected data on the use of semaglutide for adults with overweight or obesity between January 2021 and March 2022, with a follow-up of up to six months. A total of 408 patients with a BMI 27 or more were prescribed weekly semaglutide subcutaneous injections for three months or more. Patients with a history of bariatric procedures, taking other anti-obesity medications, and with an active malignant neoplasm were excluded.
The study included 175 patients (132 women [75.4%]; mean [SD] age, 49.3 [12.5] years; mean [SD] BMI, 41.3 [9.1]) in the analysis at three months and 102 patients at six months. The mean (SD) weight loss after threre months was 6.7 (4.4) kg, equivalent to a mean (SD) weight loss of 5.9% (3.7%) (p<0.001), and the mean (SD) weight loss after six months was 12.3 (6.6) kg, equivalent to a mean (SD) weight loss of 10.9% (5.8%) (p<0.001 from baseline).
Of the 102 patients who were followed up at six months, 89 (87.3%) achieved weight loss of 5% or more, 56 (54.9%) achieved weight loss of 10% or more, 24 (23.5%) achieved weight loss of 15% or more, and 8 (7.8%) achieved weight loss of 20% or more. Patients with type 2 diabetes had a lower mean (SD) percentage weight loss at three and six months compared with those without type 2 diabetes: 3.9% (3.1%) vs 6.3% (3.7%) at three months (p=0.001) and 7.2% (6.3%) vs 11.8% (5.3%) at six months (p=0.005).
The researchers added that additional studies with longer periods of follow-up are needed to evaluate prolonged weight loss outcomes.
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Can indocyanine green during laparoscopic sleeve gastrectomy be considered a new intraoperative modality for leak testing?
Italian researchers have concluded that intraoperative indocyanine green (ICG) testing may be helpful in determining which patients are at an increased risk for leakage, but there are multiple factors contribute to the pathophysiology and the incidence of gastric fistula not only the perfusion.
Reporting in BMC Surgery, the investigators sought to observe the preliminary results of the application of indocyanine green fluorescence (IGF) during laparoscopic sleeve gastrectomy (LSG) in and how the perfusion of the staple line of the stomach affects the onset of fistula.
In total, 82 patients underwent LSG with ICG fluorescence angiography from January 2020 to December 2021. 5ml of ICG was injected intravenously to identify the blood supply of the stomach, carefully assessing the angle of His.
In the ICG-tested LSG, they recorded adequate perfusion in all patients but one: the leakage rate was 1.2%. This data is inferior to the non-tested patients’ group.
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Barrett’s Esophagus in Obese Patient Post-Roux-en-Y Gastric Bypass: a Systematic Review
US researchers have found that a majority of patient with Barrett’s esophagus (BE) who underwent Roux-en-Y gastric bypass (RYGB) for weight loss had remission or improvement in BE on follow-up endoscopy.
Reporting their findings in Obesity Surgery, they conducted a systematic review of literature and the primary outcome of interest was the rate of BE resolution post-surgery. In total nine studies (104 patients had BE and underwent RYGB) were included in the review.
The rate of complete remission of intestinal metaplasia (CRIM) was 50% (p=0.937). The pooled rate of BE improvement was 52% (p=0.8) and complete remission of dysplasia was also reported in four of six patients.
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Impact of Bariatric Surgery on Renal Function
Writing in Cureus, researchers from the University Hospital Ayr, Ayr, Scotland, who looked at bariatric surgery’s effect on renal function at one, two and three year post operation (post-op), have found a statistically insignificant marginal improvement in Creatinine Clearance (CrCl) at year one post-op.
This retrospective cross-sectional single-centre study included 145 patients who underwent bariatric surgery. Renal function was calculated by using Cockroft-Gault equation, expressed as CrCl. The average age and body mass index (BMI) at referral were 48.1±8.6 years and 47.96±7.9 kgm-2 respectively, while the average age and BMI at surgery were 49.1±8.8 years and 40.62±4.2 kgm-2 respectively.
Mean CrCl at surgery, year one, year two, and year three post-op were 172.35±53.29 mL/min, 179.20±57.87 mL/min, 142.35±46.05 mL/min, and 119.56±42.46 mL/min. Marginal improvement of CrCl at year one post-op (172.35±53.29mL/min to 179.20±57.87mL/min) was statistically insignificant (p=0.731). Meanwhile, there was statistically significant CrCl decline observed from year one to year three post-op (p<0.001).
The researchers recommended further studies should take into account additional factors affecting renal function.
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Effects of a novel weight-loss combination product containing orlistat and acarbose on obesity: A randomized, placebo-controlled trial
Investigators from Sweden have reported that orlistat and acarbose can be successfully combined in a modified-release formulation to provide efficacious weight loss with no unexpected safety issues.
Writing in the journal Obesity, this randomised, double-blind, placebo-controlled trial evaluated the effect of a novel, oral, modified-release formulation of the lipase inhibitor orlistat and the glucosidase/amylase inhibitor acarbose (denoted EMP16) on relative body weight after 26 weeks compared with placebo.
Participants (aged 18 and 75 years, BMI ≥30 kg/m2 or ≥28 kg/m2 with risk factors), were randomly assigned to EMP16 120-mg orlistat/40-mg acarbose (EMP16-120/40), EMP16-150/50, or placebo. The primary end point was relative weight loss from baseline to week 26 assessed in participants with at least one post-baseline weight measurement.
Of 156 randomized participants, 149 constituted the intention-to-treat population. The mean (95% CI) estimated treatment difference to placebo in relative weight loss after 26 weeks in the intention-to-treat population was −4.70% (−6.16% to −3.24%; p<0.0001) with EMP16-120/40 and −5.42% (−6.60% to −4.24%; p<0.0001) with EMP16-150/50.
They concluded that EMP16 may be a promising candidate among other medications for improved weight management.
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