Journal watch 24/11/2021

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 an investigation into cagrilintide for weight management, a study evaluating the differences in computed tomography (CT) use between LRYGB patients with open and closed mesenteric defects, a study that found attending periodic follow-up visits does not appear to be associated with long-term weight loss outcomes, a study that found that out-of-pocket costs are US$122 less for SG than RYGB and early post-operative rapid weight loss as represented by six-month BMI loss was the main predictor of de novo cholelithiasis after bariatric surgery (please note, log-in maybe required to access the full paper).


Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial

A team of international researchers, reporting in The Lancet, have found that cagrilintide treatment in people with overweight and obesity led to significant reductions in bodyweight and was well tolerated. Natural amylin is a pancreatic hormone that induces satiety and cagrilintide is a long-acting amylin analogue. In this study, the researchers assessed the dose–response relationship of cagrilintide regarding the effects on bodyweight, safety and tolerability.


The multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial was conducted at 57 sites including hospitals, specialist clinics and primary care centres in ten countries (Canada, Denmark, Finland, Ireland, Japan, Poland, Serbia, South Africa, the UK, and the USA). PStudy participants were randomly assigned (6:1) to subcutaneous self-injections of once-weekly cagrilintide (0.3, 0.6, 1.2, 2..4 or 4.5mg), once-daily liraglutide 3.0mg or volume-matched placebo (for six placebo groups). The primary endpoint was the percentage change in bodyweight from baseline to week 26 and safety was assessed in all participants who received at least one dose of randomised treatment.


In total, 706 participants to cagrilintide 03–45 mg (100–102 per dose group), 99 to liraglutide 30 mg and 101 to placebo. According to the trial product estimand, mean percentage weight reductions from baseline were greater with all doses of cagrilintide (0.3–4.5mg, 6.0%–10.8%) versus placebo (3.0%); estimated treatment difference range 3.0%–7.8%; p<0.001). They also reported that weight reductions were also greater with cagrilintide 4.5 mg versus liraglutide 3.0 mg (10.8% vs 9.0; estimated treatment difference 1·8%, p=0·03).


The most frequent adverse events were gastrointestinal disorders (eg, nausea, constipation, and diarrhoea) and administration-site reactions. More participants receiving cagrilintide 0.3–4.5 mg had gastrointestinal adverse events compared with placebo (41%–63% vs 32%), primarily nausea (20%–47% vs 18%).


The study authors concluded that these findings support the development of molecules with novel mechanisms of action for weight management.


This study was funded by Novo Nordisk. This trial is registered with ClinicalTrials.gov, NCT03856047.


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The Influence of Mesenteric Defects Closure on the Use of Computed Tomography for Abdominal Pain 5 Years After Laparoscopic Gastric Bypass—a Post Hoc Analysis of a Randomized Clinical Trial

Investigators from Örebro University, Sweden, who evaluated the differences in computed tomography (CT) use between LRYGB patients with open and closed mesenteric defects and assessed the radiological findings and radiation doses, have report that the closure of mesenteric defects did not influence the use of CT to assess abdominal pain.


The study included 300 patients randomised to either closure (n=150) or non-closure (n=150) of mesenteric defects during LRYGB. The total number of CT scans performed due to abdominal pain in the first five postoperative years was recorded together with the radiological findings and radiation doses.


A total of 132 patients (44%) underwent 281 abdominal CT scans, including 133 scans for 67 patients with open mesenteric defects (45%) and 148 scans for 65 patients with closed mesenteric defects (43%). Radiological findings consistent with small bowel obstruction or internal hernia were found in 31 (23%) of the scans for patients with open defects and in 18 (12%) of the scans for patients with closed defects (p=0.014). At the five-year follow-up, the total radiation dose was 82,400 mGy cm in the non-closure group and 85,800 mGy cm in the closure group.


They reported their findings in Obesity Surgery.


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10-year weight loss outcomes after Roux-en-Y gastric bypass and attendance at follow-up visits: A single-center study

Reporting in SOARD, researchers from the Washington University School of Medicine in St. Louis have examined the long-term weight trajectory in patients undergoing Roux-en-Y gastric bypass (RYGB) and determined the factors predicting long-term follow-up and weight outcomes.

The study included 1,104 patients with a pre-operative BMI of 54.7 kg/m2. Follow-up data were available for 92.8% of the patients after 1 year, 50.0% after 5 years, and 35.2% after ten years post-surgery.


Black patients, compared to White individuals, were less likely to attend follow-up visits. Attendance at follow-up visits at least every other year was not associated with larger weight loss, but higher pre-operative BMI, being White (vs. Black) and female sex were. Predicted BMI reduction for a typical patient, a 45-year-old White female with a pre-operative BMI of 54.7 kg/m2 and private health insurance, undergoing laparoscopic RYGB in 2004, was 18.3 kg/m2 at year five and 17.6 kg/m2 at year ten, respectively.


The authors concluded that RYGB results in clinically significant and durable weight loss, however, attending periodic follow-up visits does not appear to be associated with long-term weight loss outcomes.


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Out-of-pocket Costs for Commercially-insured Patients in the Years Following Bariatric Surgery

Researchers from the US who compared out-of-pocket (OOP) costs for patients up to three years after laparoscopic sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) in a large, commercially-insured population, have reported that the differences between the procedures were approximately US$100 per year which may be an important factor for some patients deciding whether to pursue SG or gastric bypass.


Using data from the IBM MarketScan commercial claims database, they compared total OOP costs after the surgical episode between the two procedures using difference-in-differences analysis adjusting for demographics, comorbidities, operative year, and insurance type.


Of 63,674 patients, 64% underwent SG and 36% underwent RYGB. Adjusted OOP costs after SG were US$1083, US$1236 and US$1266 postoperative years one, two and three. For RYGB, adjusted OOP costs were US$1228, US$1377 and US$1369. The primary analysis revealed that SG OOP costs were US$122 less than RYGB year one. This difference remained consistent at –$119 in year two and –$80 in year three.


The largest clinical contributors to differences were endoscopy and outpatient care year one, outpatient care year two and emergency department use year three.


The findings were published in the Annals of Surgery.


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Predictive Factors of Cholelithiasis After Prophylactic Administration of Ursodeoxycholic Acid Following Laparoscopic Bariatric Surgery: Tehran Obesity Treatment Study

Researchers from Iran reporting the latest findings from the Tehran Obesity Treatment Study, have found that early post-operative rapid weight loss as represented by six-month BMI loss was the main predictor of de novo cholelithiasis after bariatric surgery. However, this parameter does not have enough power for discrimination of postoperative cholelithiasis.


Cholelithiasis is a well-known consequence of obesity as well as rapid weight loss especially after bariatric surgery. A routine post-operative course of ursodeoxycholic acid (UDCA) is recommended as a prophylactic measure against gallstone formation. However, the efficacy of UDCA after bariatric surgery and predictors of cholelithiasis despite prophylaxis are not well understood. Therefore, the researchers assessed the incidence and predictors of de novo cholelithiasis after bariatric surgery in patients who received UDCA prophylaxis.


They assessed data from 2,629 patients who underwent either sleeve gastrectomy or gastric bypass and received a six-month course of UDCA 300 mg twice daily. Cholelithiasis was assessed with abdominal ultrasound at baseline as well as six, nine, 12, 18 and 24 months postoperatively. The association between cholelithiasis and its predictors was examined by Cox proportional hazards models and restricted cubic spline regression.


The found that the cumulative rate of cholelithiasis in 24 months after surgery was 10.8% (n=283) with the greatest incidence within the first year. After multivariate analysis, six-month body mass index (BMI) loss was found to be the only independent predictor for postoperative cholelithiasis. The concordance index for predicting cholelithiasis was 0.60 for six-month BMI loss.


The findings were reported in Obesity Surgery.


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