Macronutrient intake, appetite, food preferences and exocrine pancreas function after treatment with short- and long-acting glucagon-like peptide-1 receptor agonists in type 2 diabetes

Glucagon-like peptide-1 receptor agonist-based agents and weight loss composition: Filling the gaps

Excess adiposity is at the root of type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as first-line treatments for T2D based on significant weight loss results. The composition of weight loss using most diets consists of <25% fat-free mass (FFM) loss, with the remainder from fat stores. Higher amounts of weight loss (achieved with metabolic bariatric surgery) result in greater reductions in FFM. Our aim was to assess the impact that GLP-1RA-based treatments have on FFM. We analysed studies that reported changes in FFM with the following agents: exenatide, liraglutide, semaglutide, and the dual incretin receptor agonist tirzepatide. We performed an analysis of various weight loss interventions to provide a reference for expected changes in FFM. We evaluated studies using dual-energy X-ray absorptiometry (DXA) for measuring FFM (a crude surrogate for skeletal muscle). In evaluating the composition of weight loss, the percentage lost as fat-free mass (%FFML) was equal to ΔFFM/total weight change. The %FFML using GLP-1RA-based agents was between 20% and 40%. In the 28 clinical trials evaluated, the proportion of FFM loss was highly variable, but the majority reported %FFML exceeding 25%. Our review was limited to small substudies and the use of DXA, which does not measure skeletal muscle mass directly. Since FFM contains a variable amount of muscle (approximately 55%), this indirect measure may explain the heterogeneity in the data. Assessing quantity and quality of skeletal muscle using advanced imaging (magnetic resonance imaging) with functional testing will help fill the gaps in our current understanding.

Strategies for minimizing muscle loss during use of incretin-mimetic drugs for treatment of obesity

The rapid and widespread clinical adoption of highly effective incretin-mimetic drugs (IMDs), particularly semaglutide and tirzepatide, for the treatment of obesity has outpaced the updating of clinical practice guidelines. Consequently, many patients may be at risk for adverse effects and uncertain long-term outcomes related to the use of these drugs. Of emerging concern is the loss of skeletal muscle mass and function that can accompany rapid substantial weight reduction; such losses can lead to reduced functional and metabolic health, weight cycling, compromised quality of life, and other adverse outcomes. Available evidence suggests that clinical trial participants receiving IMDs for the treatment of obesity lost 10% or more of their muscle mass during the 68- to 72-week interventions, approximately equivalent to 20 years of age-related muscle loss. The ability to maintain muscle mass during caloric restriction-induced weight reduction is influenced by two key factors: nutrition and physical exercise. Nutrition therapy should ensure adequate intake and absorption of high-quality protein and micronutrients, which may require the use of oral nutritional supplements. Additionally, concurrent physical activity, especially resistance training, has been shown to effectively minimize loss of muscle mass and function during weight reduction therapy. All patients receiving IMDs for obesity should participate in comprehensive treatment programs emphasizing adequate protein and micronutrient intakes, as well as resistance training, to preserve muscle mass and function, maximize the benefit of IMD therapy, and minimize potential risks.

Dietary intake by patients taking GLP-1 and dual GIP/GLP-1 receptor agonists: A narrative review and discussion of research needs

Background

Obesity and type 2 diabetes mellitus (T2DM) are increasingly common in the United States and worldwide. Because both conditions are associated with serious health consequences, weight reduction is recommended by professional medical and nutrition societies to improve outcomes. Due to the striking efficacy of glucagon-like peptide receptor agonists (GLP-1RAs) and dual mechanism glucose-dependent insulinotropic polypeptide/glucagon-like peptide receptor agonists (GIP/GLP-1RAs) for weight reduction and glycemic control, there is increased utilization for patients with obesity and/or T2DM. Yet, the impact of these medications on dietary intake is less understood.

Methods

This narrative literature review summarizes clinical studies quantifying and characterizing dietary intake in people with obesity and/or T2DM using GLP-1 or GIP/GLP-1 RAs.

Results

Though data from these studies reveal that total caloric intake was reduced by 16-39 %, few studies evaluated the actual composition of the diet.

Conclusions

Further research is needed to understand the unique nutritional needs of adults on GLP-1 or dual GIP/GLP-1RAs and to support the development of nutritional guidelines for these individuals.

Confounding Factors in the Association Between Glucagon-Like Peptide-1 Receptor Agonist Use and Retained Gastric Contents in Asymptomatic Patients Undergoing Upper Gastrointestinal Endoscopy: A Retrospective Study

Introduction The use of glucagon-like peptide-1 receptor agonists (GLP-1 RA) has gained acceptance in managing diabetic and non-diabetic patients, thanks to its benefits in treating obesity and improving cardiovascular outcomes. The potential ability of GLP-1 RA to cause retained gastric contents (RGC) which can lead to aspiration has led to the recommendation to withhold GLP-1 RA for at least one week prior to elective surgeries and procedures, including upper endoscopies and colonoscopies. However, many co-medications and conditions associated can contribute to delayed gastric emptying (DGE) and these need to be controlled to establish a clear association and incidence, which has been largely missing in most studies and reports. Our aim was to assess clinically significant delayed gastric emptying (CSDGE) related to GLP-1 RA in a "real world" situation by controlling for some common confounding factors. Method We carried out an eight-year retrospective single-center study to assess the relationship between CSDGE and the use of GLP-1 RA among asymptomatic patients undergoing upper endoscopies while controlling for common confounding factors. Result Out of the 3415 patients who had esophagogastroduodenoscopy (EGD) with or without colonoscopy (Ew/woC) during the eight-year period, 129 eligible patients were found to have CSDGE. The use of GLP-1 RA was associated with the lowest percentage frequency distribution of CSDGE, at 2%, and opiate accounted for more percentage frequency distribution, at 35%. The odds ratio for patients on GLP-1 RA who developed CSDGE was 2.5 (95% CI 0.75-8.29). All patients who had CSDGE while on GLP-1 RA were also on other medications or had conditions associated with DGE. Conclusion Our result confirmed the possible effect of confounding factors in the association between CSDGE and GLP-1 RA among asymptomatic patients undergoing Ew/woC. While the need to ensure patients' safety cannot be overemphasized, the proper approach currently favors assessing patients on a case-by-case basis while we await the results of large prospective controlled studies.

Pharmacovigilance study of GLP-1 receptor agonists for metabolic and nutritional adverse events

Aims: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are employed extensively in the management of type 2 diabetes and obesity. However, there is a paucity of real-world data on their safety and tolerability for metabolic and nutritional adverse events in large sample populations. This study aimed to analyse the metabolic and nutritional safety signatures of different GLP-1 RAs by exploring the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). Methods: AEs data were extracted from the FDA Adverse Event Reporting System database for each GLP-1 RA from the time of its launch until the second quarter of 2023. The reported odds ratio (ROR), proportional reporting ratio (PRR), Empirical Bayesian Geometric Mean and Bayesian Confidence Propagation Neural Network were employed to identify AE signals. Results: A system organ class of metabolism and nutrition disorders was employed to filter AE reports, resulting in the identification of 10,450 reports for exenatide, 2,860 reports for liraglutide, 240 reports for albiglutide, 4,847 reports for dulaglutide, 2,905 reports for semaglutide, 1,089 reports for tirzepatide, and 13 reports for lixisenatide. Semaglutide (ROR, 3.34; 95%CI, 3.22), liraglutide (ROR, 2.78; 95%CI, 2.69), and exenatide (ROR, 2.15; 95%CI, 2.11) were associated with metabolism and nutrition disorders. The number of AE signals detected were as follows: albiglutide (n = 1), lixisenatide (n = 2), tirzepatide (n = 11), exenatide (n = 12), liraglutide (n = 16), semaglutide (n = 20), dulaglutide (n = 22). Dehydration was the most frequent AE contributing to serious outcomes for liraglutide (n = 318, 23.93%), dulaglutide (n = 434, 20.90%), semaglutide (n = 370, 25.10%) and tirzepatide (n = 70, 32.86%). The time to onset (TTO) of AE was statistically different between exenatide and the other GLP-1 RAs (p < 0.001), and the Weibull parameters for dehydration for liraglutide, dulaglutide, and semaglutide analyses all showed an early failure-type profile. Conclusion: Our study suggests that exenatide, liraglutide, and semaglutide are more susceptible to metabolic and nutritional AEs than other GLP-1 RAs. Liraglutide, dulaglutide, semaglutide, and tirzepaptide's potential to induce dehydration, necessitates special attention. Despite certain deficiencies, GLP-1 RAs have considerable potential for the treatment of eating disorders.

Safe Continuation of Glucagon-like Peptide 1 Receptor Agonists at Endoscopy: A Case Series of 57 Adults Undergoing Endoscopic Sleeve Gastroplasty

PURPOSE

Glucagon-like receptor agonists (GLP1-RAs) have raised peri-procedural concerns due to their potential to delay gastric emptying. The American Association of Anesthesiologists has advised pausing a single dose before elective endoscopy. However, a subsequent directive from multiple gastroenterology societies underscored the need for further assessment to substantiate this practice. We aimed to evaluate the frequency of serious adverse events and retained gastric products during endoscopic sleeve gastroplasty (ESG) with uninterrupted GLP1-RA use.

MATERIALS AND METHODS

We conducted a retrospective evaluation of all patients undergoing ESG while on GLP1-RAs at three centers from August 2022 to February 2024. Per standard protocol, all patients had refrained from solid foods for at least 24 h and maintained nil per os for 12 h preceding their ESG. Records were reviewed for patient characteristics and medication type and doses. Primary outcomes included serious adverse events and retained gastric products based on patient records, procedure reports, and procedural videos.

RESULTS

Fifty-seven consecutive adults (89.5% women, mean age of 44 ± 9 years, mean BMI of 40.1 ± 8.1 kg/m2, 35.1% with T2DM, and 26.3% with pre-T2DM) underwent ESG without stopping GLP1-RAs, which included semaglutide (45.6%), liraglutide (19.3%), dulaglutide (22.8%), and tirzepatide (12.3%). During intubation, endoscopy, and recovery, there were no instances of retained gastric solids, pulmonary aspiration, gastroesophageal regurgitation, or hypoxia.

CONCLUSION

A ≥ 24-h pre-endoscopy liquid-only diet with ≥ 12-h pre-endoscopy fast may negate the need for GLP1-RA interruption for routine upper endoscopy in adults with native gastric anatomy.

Correlation between intestinal flora and GLP-1 receptor agonist dulaglutide in type 2 diabetes mellitus treatment-A preliminary longitudinal study

GLP-1 receptor agonists (GLP-1 RA) are presently used as the first-line drugs for the clinical treatment of type 2 diabetes mellitus (T2DM). It can regulate blood glucose by stimulating insulin secretion and lowering glucagon levels. We used 16S rRNA amplicon sequencing to detect structural changes in the composition of the intestinal flora of newly diagnosed T2DM after 1 and 48 weeks of dulaglutide administration. Our research found no significant changes in the intestinal flora after the administration of dulaglutide for 1 week to subjects with newly diagnosed T2DM. Nevertheless, after 48 weeks of dulaglutide administration, the composition of the intestinal flora changed significantly, with a significant reduction in the abundance of intestinal flora. Furthermore, we found that fasting glucose levels, fasting c-peptide levels, HbA1c levels, and BMI are also closely associated with intestinal flora. This reveals that intestinal flora may be one of the mechanisms by which dulaglutide treats T2DM.

GLP-1 receptor agonists and myocardial metabolism in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Many medical conditions, including hypertension, diabetes, obesity, sleep apnea, and heart failure (HF), increase the risk for AF. Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production. Significant changes occur in myocardial metabolism in AF. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus (T2DM) and obesity. GLP-1RAs have also been shown to reduce oxidative stress, inflammation, autonomic nervous system modulation, and mitochondrial function. This article reviews the changes in metabolic characteristics in cardiomyocytes in AF. Although the clinical trial outcomes are unsatisfactory, the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors, lowering the incidence of AF.

Diabetes remission and relapse following an intensive metabolic intervention combining insulin glargine/lixisenatide, metformin and lifestyle approaches: Results of a randomised controlled trial

AIM

Non-surgical options for inducing type 2 diabetes remission are limited. We examined whether remission can be achieved by combining lifestyle approaches and short-term intensive glucose-lowering therapy.

METHODS

In this trial, 160 patients with type 2 diabetes on none to two diabetes medications other than insulin were randomised to (a) an intervention comprising lifestyle approaches, insulin glargine/lixisenatide and metformin, or (b) standard care. Participants with glycated haemoglobin (HbA1c) <7.3% (56 mmol/mol) at 12 weeks were asked to stop diabetes medications and were followed for an additional 52 weeks. The primary outcome was diabetes relapse defined as HbA1c ≥6.5% (48 mmol/mol) at 24 weeks or thereafter, capillary glucose ≥10 mmol/L on ≥50% of readings, or use of diabetes medications, analysed as time-to-event. Main secondary outcomes included complete or partial diabetes remission at 24, 36, 48 and 64 weeks defined as HbA1c <6.5% (48 mmol/mol) off diabetes medications since 12 weeks after randomisation. A hierarchical testing strategy was applied.

RESULTS

The intervention significantly reduced the hazard of diabetes relapse by 43% (adjusted hazard ratio 0.57, 95% confidence interval 0.40-0.81; p = .002). Complete or partial diabetes remission was achieved in 30 (38.0%) intervention group participants versus 16 (19.8%) controls at 24 weeks and 25 (31.6%) versus 14 (17.3%) at 36 weeks [relative risk 1.92 (95% confidence interval 1.14-3.24) and 1.83 (1.03-3.26), respectively]. The relative risk of diabetes remission in the intervention versus control group was 1.88 (1.00-3.53) at 48 weeks and 2.05 (0.98-4.29) at 64 weeks.

CONCLUSIONS

A 12-week intensive intervention comprising insulin glargine/lixisenatide, metformin and lifestyle approaches can induce remission of diabetes.

GLP-1 receptor agonists modulate blood glucose levels in T2DM by affecting Faecalibacterium prausnitzii abundance in the intestine

BACKGROUND

Glucagon-like peptide 1 (GLP-1) receptor agonists are a class of medications used to treat type 2 diabetes, including metformin, which is considered first-line therapy for type 2 diabetes. In recent years, GLP-1 receptor agonists (GLP-1 RAs) have been found to alter the composition and structure of gut flora and also promote the production of gut probiotics. However, there have been few clinical studies regarding the effects of GLP-1 RAs on gut flora. In this study, we investigated changes in the abundance of Lactobacillus delbrueckii (L delbrueckii) and Faecalibacterium prausnitzii (F prausnitzii) 1 week after administration of a GLP-1 RA in the clinical treatment of type 2 diabetes. The association with glycemic and body mass index (BMI) correlations was also explored.

METHODS

Twelve newly diagnosed patients with type 2 diabetes were examined for changes in the abundance of L delbrueckii and F prausnitzii by Fluorescence in Situ Hybridization 1 week after administration of GLP-1 RAs. Subjects BMI was measured and fasting glucose changes were detected using the glucose oxidase method, and Spearman correlation analysis was performed to explore their relevance.

RESULTS

There was no significant change in the abundance of L delbrueckii in the intestine (P = .695) and no significant correlation with BMI and fasting glucose levels (R = 0.134, P = .534) after the use of GLP-1 RA (R = -0.098, P = .647); F prausnitzii on the other hand had a significantly higher abundance (P = .002) and a significant negative correlation with fasting glucose level (R = -0.689, P < .001), but no significant correlation with BMI (R = -0.056, P = .796).

CONCLUSION

F prausnitzii may be one of the pathways through which glucose is regulated in the treatment of type 2 diabetes by GLP-1 RAs.

A Comprehensive Review on Weight Loss Associated with Anti-Diabetic Medications

Obesity is a complex metabolic condition that can have a negative impact on one's health and even result in mortality. The management of obesity has been addressed in a number of ways, including lifestyle changes, medication using appetite suppressants and thermogenics, and bariatric surgery for individuals who are severely obese. Liraglutide and semaglutide are two of the five Food and Drug Administration (FDA)-approved anti-obesity drugs that are FDA-approved agents for the treatment of type 2 diabetes mellitus (T2DM) patients. In order to highlight the positive effects of these drugs as anti-obesity treatments, we analyzed the weight loss effects of T2DM agents that have demonstrated weight loss effects in this study by evaluating clinical studies that were published for each agent. Many clinical studies have revealed that some antihyperglycemic medications can help people lose weight, while others either cause weight gain or neutral results. Acarbose has mild weight loss effects and metformin and sodium-dependent glucose cotransporter proteins-2 (SGLT-2) inhibitors have modest weight loss effects; however, some glucagon-like peptide-1 (GLP-1) receptor agonists had the greatest impact on weight loss. Dipeptidyl peptidase 4 (DPP-4) inhibitors showed a neutral or mild weight loss effect. To sum up, some of the GLP-1 agonist drugs show promise as weight-loss treatments.

Association of glucagon-like peptide-1 receptor agonist treatment with gastric residue in an esophagogastroduodenoscopy

AIMS/INTRODUCTION

Previous studies have reported that the glucagon-like peptide-1 receptor agonist (GLP-1RA) delays gastric emptying, and gastric emptying was assessed by the ¹³ C breath test or paracetamol absorption technique. However, neither of them is clinically familiar in real-world clinical practice. The purpose of the present study was to investigate the association between GLP-1RA treatment and gastric residue in an esophagogastroduodenoscopy.

MATERIALS AND METHODS

This study was a matched pair case-control study. The study population consisted of 1,128 individuals with diabetes who had esophagogastroduodenoscopy at our clinic between July 2020 and June 2022. To account for differences in characteristics, such as age, sex, insulin treatment and glycated hemoglobin, we carried out a one-to-one nearest neighbor propensity score matching analysis between diabetes patients with and without GLP-1RA treatment. After matching, we compared the presence of gastric residue in an esophagogastroduodenoscopy by the McNemar test between patients with and without GLP-1RA treatment.

RESULTS

After the propensity score matching, we selected 205 pairs. In the propensity score-matched comparison, the proportion of gastric residue was statistically significantly higher in the GLP-1RA treatment group (0.49% vs 5.4%, P = 0.004). The details of GLP-1RA prescribed for the 11 patients with gastric residue were liraglutide once daily 1.8 mg (n = 2), dulaglutide once weekly 0.75 mg (n = 5), semaglutide once weekly 0.5 mg (n = 2) and semaglutide once weekly 1.0 mg (n = 2).

CONCLUSION

GLP-1RA treatment is associated with gastric residue in an esophagogastroduodenoscopy in patients with diabetes.

Tirzepatide suppresses palatable food intake by selectively reducing preference for fat in rodents

AIM

To investigate the role of glucose-dependent insulinotropic polypeptide receptor (GIPR) agonists alone or combined with glucagon-like peptide-1 receptor (GLP-1R) agonists to regulate palatable food intake and the role of specific macronutrients in these preferences.

METHODS

To understand this regulation, we treated mice and rats on several choice diet paradigms of chow and a palatable food option with individual or dual GIPR and GLP-1R agonists.

RESULTS

In mice, the dual agonist tirzepatide suppressed total caloric intake, while promoting the intake of chow over a high fat/sucrose diet. Surprisingly, GIPR agonism alone did not alter food choice. The food intake shift observed with tirzepatide in wild-type mice was completely absent in GLP-1R knockout mice, suggesting that GIPR signalling does not regulate food preference. Tirzepatide also selectively suppressed the intake of palatable food but not chow in a rat two-diet choice model. This suppression was specific to lipids, as GLP-1R agonist and dual agonist treatment in rats on a choice paradigm assessing individual palatable macronutrients robustly inhibited the intake of Crisco (lipid) without decreasing the intake of a sucrose (carbohydrate) solution.

CONCLUSIONS

Decreasing preference for high-caloric, high-fat foods is a powerful action of GLP-1R and dual GIPR/GLP-1R agonist therapeutics, which may contribute to the weight loss success of these drugs.

Macronutrient intake: Hormonal controls, pathological states, and methodological considerations

A plethora of studies to date has examined the roles of feeding-related peptides in the control of food intake. However, the influence of these peptides on the intake of particular macronutrient constituents of food - carbohydrate, fat, and protein - has not been as extensively addressed in the literature. Here, the roles of several feeding-related peptides in controlling macronutrient intake are reviewed. Next, the relationship between macronutrient intake and diseases including diabetes mellitus, obesity, and eating disorders are examined. Finally, some key considerations in macronutrient intake research are discussed. We hope that this review will shed light onto this underappreciated topic in ingestive behavior research and will help to guide further scientific investigation in this area.