Chronic intrahypothalamic rather than subcutaneous liraglutide treatment reduces body weight gain and stimulates the melanocortin receptor system

Weight Regain after Metabolic Surgery: Beyond the Surgical Failure

Patients undergoing metabolic surgery have factors ranging from anatomo-surgical, endocrine metabolic, eating patterns and physical activity, mental health and psychological factors. Some of the latter can explain the possible pathophysiological neuroendocrine, metabolic, and adaptive mechanisms that cause the high prevalence of weight regain in postbariatric patients. Even metabolic surgery has proven to be effective in reducing excess weight in patients with obesity; some of them regain weight after this intervention. In this vein, several studies have been conducted to search factors and mechanisms involved in weight regain, to stablish strategies to manage this complication by combining metabolic surgery with either lifestyle changes, behavioral therapies, pharmacotherapy, endoscopic interventions, or finally, surgical revision. The aim of this revision is to describe certain aspects and mechanisms behind weight regain after metabolic surgery, along with preventive and therapeutic strategies for this complication.

Brown Adipose Tissue: A New Potential Target for Glucagon-like Peptide 1 Receptor Agonists in the Treatment of Obesity

Adipose tissue can be divided into white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, according to the differences in morphology. WAT acts as a buffer for increased energy intake and decreased energy expenditure during the development of obesity, resulting in visceral and ectopic WAT accumulation. These WAT depots are strongly associated with chronic systemic inflammation, insulin resistance, and cardiometabolic risk related to obesity. They represent a primary weight loss target in anti-obesity management. Second-generation anti-obesity medications glucagon-like peptide-1 receptor agonists (GLP-1RAs) cause weight loss and improve body composition by reducing visceral and ectopic fat depots of WAT, resulting in improved cardiometabolic health. Recently, the understanding of the physiological significance of BAT beyond its primary function in generating heat through non-shivering thermogenesis has been expanded. This has raised scientific and pharmaceutical interest in the manipulation of BAT to further enhance weight reduction and body weight maintenance. This narrative review focuses on the potential impact of GLP-1 receptor agonism on BAT, particularly in human clinical studies. It provides an overview of the role of BAT in weight management and highlights the need for further research to elucidate the mechanisms by which GLP-1RAs affect energy metabolism and weight loss. Despite encouraging preclinical data, limited clinical evidence supports the notion that GLP-1RAs contribute to BAT activation.

Assessing the Continuation of Glucagon-Like Peptide-1 Receptor Agonists When Weight and HBA1C Are Not Reduced

Background: Glucagon-like peptide-1 agonists (GLP-1) reportedly lower HbA1c and promote weight reduction and improve cardiovascular outcomes. The primary objective of this study was to evaluate the use of GLP-1 agents in patients and changes in HbA1c, weight loss, blood pressure, and lipoid profiles. Methods: Patient information was extracted from a regional Veteran Affairs data mart. Patients were included if they had prescriptions for at least 90 days of a GLP-1 between April 1, 2005, and December 1, 2016, and HbA1Cs and weights at both baseline and within first 15 months of therapy. Blood pressure and lipids were also measured. Pearson's correlation and multiple regression analysis were used. Results: Three hundred twenty-two patients met inclusion criteria. Average HbA1c decreased by 0.81% and weight by 4.4 kg. At 1 year, 160 patients had both weight and HbA1c measured, and of those, 92 (58%) patients had HbA1c reduction of at least 0.5% and 94 (59%) patients had <-2 kg change in weight. Fifty-seven (36%) patients met both of those outcomes. Veterans who met both weight and HbA1c outcomes were slightly, but significantly, older than those who did not meet both. No correlation was found between weight and HbA1c change at each quarter (P > 0.05); however, weight change was correlated with systolic blood pressure change (P = 0.03). Multiple regression for meeting weight and HbA1c target outcomes, and changes at quarters 1-3, all correlated to success at 1 year (P < 0.05). Conclusions: Weight change was independent of HbA1c changes in patients receiving GLP-1s for diabetes control. Weight loss was associated with decreases in systolic BP.

Of mice and men: incretin actions in the central nervous system

Incretins have risen to the forefront of therapies for obesity and related metabolic complications, primarily because of their efficacy and relatively few side effects. Importantly, their efficacy in altering energy balance and decreasing body weight is apparently through actions in the central nervous system (CNS); the latter may have implications beyond obesity per se, i.e. in other disease states associated with obesity including CNS-related disorders. Here, we first describe the role of the CNS in energy homeostasis and then the current state of knowledge in terms of incretin physiology, pathophysiology and efficacy in preclinical and clinical studies. In the future, more clinical studies are needed to fully map mechanistic pathways underlying incretin actions and outcomes in the human CNS. Additionally, future research will likely lead to the discovery of additional novel incretins and/or more efficacious medications with less side effects through the improvement of current compounds with properties that would allow them to have more favorable pharmacokinetic and pharmacodynamic profiles and/or by combining known and novel incretins into safe and more efficacious combination therapies leading ultimately to more tangible benefits for our patients.

Liraglutide pharmacotherapy reduces body weight and improves glycaemic control in juvenile obese/hyperglycaemic male and female rats

AIMS

To examine whether the glucagon-like peptide-1 receptor agonist liraglutide could be used in juvenile male and female rats as an anti-obesity/diabetic pharmaceutical to prevent not only adolescent obesity/hyperglycaemia, but also early-adult onset obesity.

MATERIAL AND METHODS

Pregnant dams were fed either standard chow or a high-fat, high-sucrose diet (HFSD) from gestational day 2, throughout pregnancy and lactation. Offspring were weaned onto the respective maternal diet. Juveniles received daily subcutaneous injection of liraglutide (50 μg/kg, from postnatal day [PND]30 to PND40 and 200 μg/kg from PND40 to PND60) or vehicle. Food intake, body weight and glycaemic levels were evaluated across the experimental period.

RESULTS

Chronic liraglutide administration in juveniles prevented body weight gain in males and retained a normoglycaemic profile in both male and female rats.

CONCLUSION

These preclinical data suggest that maternal and early-life consumption of an HFSD increases caloric intake, body weight gain and hyperglycaemia, a collective set of unwanted metabolic effects that appear to be treatable in juveniles with liraglutide pharmacotherapy intervention.

Patients with Obesity Caused by Melanocortin-4 Receptor Mutations Can Be Treated with a Glucagon-like Peptide-1 Receptor Agonist

Pathogenic mutations in the appetite-regulating melanocortin-4 receptor (MC4R) represent the most common cause of monogenic obesity with limited treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) cause weight loss by reducing appetite. We assessed the effect of the GLP-1 RA liraglutide 3.0 mg for 16 weeks in 14 obese individuals with pathogenic MC4R mutations (BMI 37.5 ± 6.8) and 28 matched control participants without MC4R mutation (BMI 36.8 ± 4.8). Liraglutide decreased body weight by 6.8 kg ± 1.8 kg in individuals with pathogenic MC4R mutations and by 6.1 kg ± 1.2 kg in control participants. Total body fat, waist circumference, and fasting and postprandial glucose concentrations similarly decreased in both groups. Thus, liraglutide induced an equal, clinically significant weight loss of 6% in both groups, indicating that the appetite-reducing effect of liraglutide is preserved in MC4R causal obesity and that liraglutide acts independently of the MC4R pathway. Thus, liraglutide could be an effective treatment of the most common form of monogenic obesity.