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 surgery and cancer risk, increase in US surgery procedures, post-op bone health on adolescent patients, results from multi-centre Polish Revision Obesity Surgery Study (PROSS), microvascular and macrovascular diseases and diabetes remission after bariatric surgery, comparison of HbA1c one year after OAGB or RYGB and patients’ perceptions of living with obesity and surgery, and more (please note, log-in maybe required to access the full paper).
Bariatric Surgery and Longitudinal Cancer Risk - A Review
A study led by researchers from the Mayo Clinic Arizona, Phoenix, AZ, have published a review that provides a framework to better define subgroups of patients at higher risk of developing cancer who would potentially benefit more from bariatric surgery, as well as subgroups where more caution should be exercised.
The review summarises how obesity leads to an increased risk of developing cancer and synthesises current evidence behind the potential for bariatric surgery to reduce longitudinal cancer risk. They report that bariatric surgery appears to have the strongest and most consistent association with decreased incidence of developing breast, ovarian and endometrial cancers. In addition, the association of bariatric surgery and the development of oesophageal, gastric, liver and pancreas cancer is heterogenous with studies showing either no association or decreased longitudinal incidences. However, there have been preclinical and cohort studies implying an increased risk of developing colon and rectal cancer after bariatric surgery.
A review and synthesis of the existing literature reveals epidemiologic shortcomings of cohort studies that potentially explain incongruencies observed between studies. They concluded that studies examining the association of bariatric surgery and longitudinal cancer risk remain heterogeneous and could be explained by certain epidemiologic considerations.
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American Society for Metabolic and Bariatric Surgery 2022 estimate of metabolic and bariatric procedures performed in the United States
US researchers have report that the total number of metabolic and bariatric surgery (MBS) procedures performed increased from approximately 262,893 in 2021 to 280,000 in 2022.
Writing in SOARD, they reviewed data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and National Surgical Quality Improvement Program. They noted that sleeve gastrectomy continues to be the most commonly performed procedure, with gastric bypass procedure trend remaining relatively stable.
The percentage of revision procedures and biliopancreatic diversion with duodenal switch procedures increased slightly. Intragastric balloons placement increased from the previous year, whilst endoscopic sleeve gastroplasty increased in numbers.
The 6.5% increase in MBS volume from 2021 to 2022 and a 41% increase from 2020 which demonstrates a recovery from the COVID-19 pandemic.
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Bone health following paediatric and adolescent bariatric surgery: a systematic review and meta-analysis
A study led by researcher from Imperial College London, London, UK, have found that bariatric surgery effectively reduces weight in paediatric patients, but Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) may have adverse effects on bone health in the medium term.
Writing in eClinicalMedicine, this review and meta-analysis aimed to assess the impact of paediatric bariatric surgery on bone health. They identified 12 studies with 681 patients across five countries (mean age 17 ± 0.57 years). Patients underwent RYGB (n=216), SG (n=257), gastric band (n=184) or intragastric balloon placement (n=24). Surgery was associated with significant weight reduction (p<0.001) with RYGB being most effective (p<0.001).
Patients who underwent SG or RYGB had significantly lower lumbar bone mineral density, −0.96 g/cm2 (95% CI −0.1 to −0.03, p<0.001), Z score, −1.132 (95% CI −1.8 to −0.45, p<0.001) and subtotal body bone mineral density, −0.7 g/cm2 (95% CI −1.2 to −0.2, p<0.001) following surgery. This was accompanied with higher markers of bone resorption, C-terminal telopeptide of type 1 collagen 0.22 ng/ml (95% CI 0.12–0.32, p<0.001) and osteocalcin, 10.83 ng/ml (95% CI 6.01–15.67, p<0.001). There was a significant reduction in calcium levels following BS, −3.78 mg/dl (95% CI −6.1 to −1.5, p<0.001) but no difference in 25-hydroxyvitamin D, phosphate, bone alkaline phosphatase, procollagen type 1 N propeptide or parathyroid hormone.
The researchers emphasised that it is crucial to monitor and support bone health through appropriate nutritional supplementation and judicious follow-up, and that long-term data is needed to fully understand the clinical implications of these findings on bone outcomes.
The study was funded by the Medical Research Council.
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The outcomes of Re-Redo bariatric surgery—results from multicenter Polish Revision Obesity Surgery Study (PROSS)
Polish researchers, writing on behalf of the PROSS–Collaborative Study Group, have reported that although re-redo bariatric surgery is an effective treatment for obesity, it carries a significant risk of complications.
Writing in Scientific Reports, they conducted a retrospective cohort study on a group of 799 patients who underwent redo bariatric surgery between 2010 and 2020. Among these patients, 20 individuals underwent a second elective redo bariatric surgery (Re-Redo) because of weight regain (15 patients) or insufficient weight loss, i.e. < 50% EWL (5 patients).
The mean BMI before re-redo surgery was 38.8±4.9kg/m2. Mean age was 44.4±11.5 years old. The mean %TWL before and after re-redo was 17.4±12.4% and %EBMIL was 51.6±35.9%. Thirteen of 20 patients (65%) achieved >50% EWL. The mean final %TWL was 34.2±11.1% and final %EBMIL was 72.1±20.8%. The mean BMI after treatment was 31.9±5.3kg/m2.
However, they reported that complications occurred in three of 20 patients (15%), with no reported mortality or need for another surgical intervention.
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The association between microvascular and macrovascular diseases and diabetes remission after bariatric surgery
A study led by researchers from Mayo Clinic, Rochester, MN, have reported patients with presurgical diabetes-associated diseases had a lower remission rate after RYGB and SG.
Writing in Surgical Endoscopy, this retrospective cohort study included 536 patients. Patients without diabetes-associated diseases had an OR of 2.72 (95% CI 1.92 to 3.88) to achieve T2DM remission vs patients with diabetes-associated diseases (27.9% vs 59.4%; p<0.001). There was an additive effect of the number of diabetes-associated diseases on the T2DM remission (p<0.001) and there was a significant association between HbA1c (p<0.001), number of diabetes medications (p<0.001), T2DM duration (p<0.001), surgery type (p=0.009) and insulin use (p=0.04) with T2DM remission.
“Not only do these complications represent a more practical and consistent variable to predict T2DM remission, but also help planning a multidisciplinary management of patients with more severe T2DM,” they concluded.
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Variation in HbA1c in Patients with Obesity and type 2 Diabetes Mellitus 12 months after Laparoscopic One-Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y Gastric Bypass: a Retrospective Matched Cohort Study
Researchers from The Netherlands have reported that laparoscopic one-anastomosis gastric bypass (OAGB) leads to lower HbA1c one year after surgery vs laparoscopic Roux-en-Y gastric bypass (RYGB), without a difference in weight loss.
Writing in Obesity Surgery, a total of 152 patients (38 OAGB and 114 RYGB) were included in the study. Mean (standard deviation (SD)) HbA1c was 7.49 (1.51)% in the OAGB group and 7.56(1.23)% in the RYGB group at baseline. Twelve months after surgery the mean (SD) HbA1c dropped to 5.73 (0.71)% after OAGB and 6.09 (0.76)% after RYGB (adjusted p=0.011). The mean (SD) BMI was reduced from 42.5(6.3) kg/m2 to 29.6(4.7) kg/m2 after OAGB and 42.3(5.8) kg/m2 to 29.9 (4.5) kg/m2 after RYGB; reflecting 30.3 (6.8) %TWL post-OAGB and 29.0 (7.3) %TWL post-RYGB (p=0.34).
The researcher called for additional prospective randomised studies to ascertain the most optimal metabolic treatment for patients with obesity and T2DM.
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‘Surgery is my only hope’: A qualitative study exploring perceptions of living with obesity and the prospect of having bariatric surgery
Integrating mindfulness, mindful eating and self-compassion before and after bariatric surgery could be beneficial for patients to support positive adaptive coping mechanisms, and to promote helpful eating behaviour to optimise response to bariatric surgery, especially for individuals who experience self-blame and self-stigmatisation, according to a study led by researchers from Birmingham City University, Birmingham, UK.
Writing in Clinical Obesity, the investigators noted that despite the benefits of bariatric surgery in terms of physical health, the literature reports that the psychological benefits of bariatric surgery may have a limited time effect of approximately two years before returning to the levels observed pre-surgery. Therefore, they explored the attitudes, beliefs, and experiences of 17 individuals living with obesity who were preparing to undergo bariatric surgery (n=12) or had recently undergone a bariatric surgery procedure (n=5).
They found that people living with obesity displayed high optimism for positive outcomes, with participants hoping that bariatric surgery would be different to previous attempts at weight regulation. However, they reported that there was unrealistic optimism, with many pre-surgery participants not relaying the realistic possibility of post-surgery weight-regain. Despite the optimism individuals feel about bariatric surgery, participants felt that the psychological factors influencing eating behaviours are not being addressed by healthcare.
“These findings suggest that mindfulness, mindful eating, and self-compassion approaches should be incorporated into clinical practice to support weight regulation and adaption to physiological changes after bariatric surgery,” they concluded.
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