Pharmacotherapy before and after bariatric surgery

The risk and benefit of revisional vs. primary metabolic- bariatric surgery and drug therapy - A narrative review

Metabolic and bariatric surgery (MBS) leads to long-term weight loss, reduced risk of cardiovascular events and cancer, and reduced mortality. Sleeve gastrectomy and Roux-en-Y gastric bypass are currently the most common surgical techniques. Weight loss after MBS was previously believed to work through restriction and malabsorption, however, mechanistic studies show that MBS techniques with long term efficacy instead alter physiological signaling between the gut and the brain. In revisional MBS, the initial surgical technique is corrected, modified, or converted to a new one. The indication for revisional MBS can be to achieve further weight loss or improvement in obesity comorbidity, but it may be necessary due to complications (e.g., gastroesophageal reflux or obstruction). Revisional MBS is associated with an increased risk of surgical complications and often less weight loss compared to the results following primary surgery. This narrative review summarizes data from revisional MBS where information is often presented with inconsistent definitions for indications and outcomes, making comparison between strategies difficult. In summary, we suggest careful weighing of potential benefits and risks with revisional MBS, bearing in mind the option of add-on therapy with new anti-obesity drugs.

Semaglutide and Tirzepatide for the Management of Weight Recurrence After Sleeve Gastrectomy: A Retrospective Cohort Study

BACKGROUND

Metabolic and bariatric surgery (MBS) is the most effective treatment for obesity and improvement of obesity-associated comorbidities. However, a proportion of these patients may suffer from weight recurrence and recurrence of obesity-associated comorbidities.

METHOD

A retrospective cohort study of patients who underwent SG between January 2008 and August 2022 and sought treatment for weight recurrence with semaglutide or tirzepetide from January 2022 onwards.

RESULT

A total of 115 patients were included, of which 70 had SG and treated for weight recurrence with semaglutide and 45 had SG and treated with tirzepatide. The mean age of patients was 38.8 (10.4) and 80.9% of patients were female. The mean pre-treatment weight and BMI was 94.0 (23.8) kg and 35.1 (6.0) kg/m2. Following treatment with semaglutide and tirzepatide, the mean post-treatment weight at 6 months was 81.0 (19.0) kg from 90.1 (19.6) kg and 87.6 (28.3) kg from 100.2 (28.5) kg respectively, corresponding to a clinically significant mean weight loss from baseline to 6 months of 10.3 (5.9)% (p < 0.05) and 15.5 (6.3)% (p < 0.05). Weight loss in tirzepatide patients was significantly greater than the semaglutide patients at 6 months (p < 0.02). There were no reported severe adverse events to the treatment.

CONCLUSION

Short-term outcomes show that semaglutide and tirzepatide can be an effective treatment for managing weight recurrence after SG. Studies with longer follow-up are needed to determine the durability, as weight regain after discontinuation of the medication is highly likely, and the high cost of these medications can limit their use.

Bariatric surgery, through beneficial effects on underlying mechanisms, improves cardiorenal and liver metabolic risk over an average of ten years of observation: A longitudinal and a case-control study

BACKGROUND

Bariatric surgery has long-term beneficial effects on body weight and metabolic status, but there is an apparent lack of comprehensive cardiometabolic, renal, liver, and metabolomic/lipidomic panels, whereas the underlying mechanisms driving the observed postoperative ameliorations are still poorly investigated. We aimed to study the long-term effects of bariatric surgery on metabolic profile, cardiorenal and liver outcomes in association with underlying postoperative gut hormone adaptations.

METHODS

28 individuals who underwent bariatric surgery [17 sleeve gastrectomy (SG), 11 Roux-en-Y gastric bypass (RYGB)] were followed up 3, 6 and 12 and at 10 years following surgery. Participants at 10 years were cross-sectionally compared with an age-, sex- and adiposity-matched group of non-operated individuals (n = 9) and an age-matched pilot group of normal-weight individuals (n = 4).

RESULTS

There were durable effects of surgery on body weight and composition, with an increase of lean mass percentage persisting despite some weight regain 10 years postoperatively. The improvements in metabolic and lipoprotein profiles, cardiometabolic risk markers, echocardiographic and cardiorenal outcomes persisted over the ten-year observation period. The robust improvements in insulin resistance, adipokines, activin/follistatin components and postprandial gastrointestinal peptide levels persisted 10 years postoperatively. These effects were largely independent of surgery type, except for a lasting reduction of ghrelin in the SG subgroup, and more pronounced increases in proglucagon products, mainly glicentin and oxyntomodulin, and in the cardiovascular risk marker Trimethylamine-N-oxide (TMAO) within the RYGB subgroup. Despite similar demographic and clinical features, participants 10 years after surgery showed a more favorable metabolic profile compared with the control group, in conjunction with a dramatic increase of postprandial proglucagon product secretion.

CONCLUSIONS

We demonstrate that cardiorenal and metabolic benefits of bariatric surgery remain robust and largely unchanged ten years postoperatively and are associated with durable effects on gastrointestinal- muscle- and adipose tissue-secreted hormones.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04170010.

Physiological Appetite Regulation and Bariatric Surgery

Obesity remains a common metabolic disorder and a threat to health as it is associated with numerous complications. Lifestyle modifications and caloric restriction can achieve limited weight loss. Bariatric surgery is an effective way of achieving substantial weight loss as well as glycemic control secondary to weight-related type 2 diabetes mellitus. It has been suggested that an anorexigenic gut hormone response following bariatric surgery contributes to weight loss. Understanding the changes in gut hormones and their contribution to weight loss physiology can lead to new therapeutic treatments for weight loss. Two distinct types of neurons in the arcuate hypothalamic nuclei control food intake: proopiomelanocortin neurons activated by the anorexigenic (satiety) hormones and neurons activated by the orexigenic peptides that release neuropeptide Y and agouti-related peptide (hunger centre). The arcuate nucleus of the hypothalamus integrates hormonal inputs from the gut and adipose tissue (the anorexigenic hormones cholecystokinin, polypeptide YY, glucagon-like peptide-1, oxyntomodulin, leptin, and others) and orexigeneic peptides (ghrelin). Replicating the endocrine response to bariatric surgery through pharmacological mimicry holds promise for medical treatment. Obesity has genetic and environmental factors. New advances in genetic testing have identified both monogenic and polygenic obesity-related genes. Understanding the function of genes contributing to obesity will increase insights into the biology of obesity. This review includes the physiology of appetite control, the influence of genetics on obesity, and the changes that occur following bariatric surgery. This has the potential to lead to the development of more subtle, individualised, treatments for obesity.

Effects of Mulberry Leaf Fu Tea on the Intestines and Intestinal Flora of Goto-Kakizaki Type 2 Diabetic Rats

Type 2 diabetes mellitus is a disease caused by hyperglycemia, an imbalance in the intestinal flora and disruption of the endocrine system. At present, it is primarily controlled through drug treatment and an improved diet. Mulberry leaf and fu brick tea were considered to have excellent hypoglycemic effects. This study used mulberry leaves and fu brick tea as raw materials to develop a dietary regulator that can assist in the prevention and alleviation of diabetes. The experiment used the Goto-Kakizaki (GK) rat model to investigate the hypoglycemic effect of mulberry leaf fu tea (MFT) and its influence on the intestinal flora of diabetic rats through methods including ELISA, tissue section observation and 16S RNA microbial sequencing. The results showed that, compared with the GK group, the intervention of mulberry leaf fu tea significantly reduced the activities of α-glucosidase (p < 0.05) and α-amylase (p < 0.05) in the duodenum of GK diabetic rats. The height of the duodenal villi was significantly reduced (p < 0.001), leading to decreased intestinal sugar absorption. At the same time, MFT alleviates the imbalance of intestinal flora caused by high blood sugar, promotes the growth of beneficial bacteria (Lactobacillus, Bifidobacterium, etc.), and inhibits the reproduction of harmful bacteria (Blautia, Klebsiella, Helicobacter, Alistipes, etc.). MFT helps reduce the secretion of toxic substances (lipopolysaccharide, p < 0.001), decreases oxidative stress and inflammation, mitigates organ damage, and improves symptoms of diabetes. Finally, the random blood glucose value of GK rats dropped from 22.79 mmol/L to 14.06 mmol/L. In summary, mulberry leaf fu tea can lower sugar absorption in diabetic rats, reduce the body's oxidative stress and inflammatory response, regulate intestinal flora, and reduce blood sugar levels in GK rats. It is hinted that mulberry leaf fu tea could be used as a functional drink to help prevent the occurrence of diabetes.