Bardet-Biedl syndrome: A focus on genetics, mechanisms and metabolic dysfunction.

Bardet-Biedl syndrome (BBS) is a rare, monogenic, multisystem disorder characterized by retinal dystrophy, renal abnormalities, polydactyly, learning disabilities, as well as metabolic dysfunction, including obesity and an increased risk of type 2 diabetes. It is a primary ciliopathy, and causative mutations in more than 25 different genes have been described. Multiple cellular mechanisms contribute to the development of the metabolic phenotype associated with BBS, including hyperphagia as a consequence of altered hypothalamic appetite signalling as well as alterations in adipocyte biology promoting adipocyte proliferation and adipogenesis. Within this review, we describe in detail the metabolic phenotype associated with BBS and discuss the mechanisms that drive its evolution. In addition, we review current approaches to the metabolic management of patients with BBS, including the use of weight loss medications and bariatric surgery. Finally, we evaluate the potential of targeting hypothalamic appetite signalling to limit hyperphagia and induce clinically significant weight loss.

The melanocortin-4 receptor pathway and the emergence of precision medicine in obesity management.

Over the past few decades, there has been a global surge in the prevalence of obesity, rendering it a globally recognized epidemic. Contrary to simply being a medical condition, obesity is an intricate disease with a multifactorial aetiology. Understanding the precise cause of obesity remains a challenge; nevertheless, there seems to be a complex interplay among biological, psychosocial and behavioural factors. Studies on the genetic factors of obesity have revealed several pathways in the brain that play a crucial role in food intake regulation. The best characterized pathway, thus far, is the leptin-melanocortin pathway, from which disruptions are responsible for the majority of monogenic obesity disorders. The effectiveness of conservative lifestyle interventions in addressing monogenic obesity has been limited. Therefore, it is crucial to complement the management strategy with pharmacological and surgical options. Emphasis has been placed on developing drugs aimed at replacing the absent signals, with the goal of restoring the pathway. In both monogenic and polygenic forms of obesity, outcomes differ across various interventions, likely due to the multifaceted nature of the disease. This underscores the need to explore alternative therapeutic strategies that can mitigate this heterogeneity. Precision medicine can be regarded as a powerful tool that can address this concern, as it values the understanding of the underlying abnormality triggering the disease and provides a tailored treatment accordingly. This would assist in optimizing outcomes of the current therapeutic approaches and even aid in the development of novel treatments capable of more effectively managing the global obesity epidemic.

Abolishing ß-arrestin recruitment is necessary for the full metabolic benefits of G protein-biased glucagon-like peptide-1 receptor agonists.

AIM: Earlier studies have shown that peptide glucagon-like peptide-1 receptor (GLP-1R) agonists with reduced ß-arrestin recruitment show enhanced anti-hyperglycaemic efficacy through avoidance of GLP-1R desensitization. However, the ligand modifications needed to decrease ß-arrestin recruitment usually also reduces GLP-1R affinity, therefore higher doses are needed. Here we aimed to develop new, long-acting, G protein-biased GLP-1R agonists with acute signalling potency comparable with semaglutide, to provide insights into specific experimental and therapeutic scenarios. MATERIALS AND METHODS: New GLP-1R agonist peptides were assessed using a variety of in vitro and in vivo assays. RESULTS: First, we show that very substantial reductions in ß-arrestin recruitment efficacy are required to realize fully the benefits of GLP-1R agonism on blood glucose lowering in mice, with more moderate reductions being less effective. Secondly, our lead compound (SRB107) performs substantially better than semaglutide for effects on blood glucose and weight loss, which may be jointly attributable to its biased agonist action and protracted pharmacokinetics. Thirdly, we show that biased agonist-specific GLP-1R internalization profiles occur at clinically relevant pharmacological concentrations. Finally, we show that SRB107 cAMP signalling is differentially modulated by single and double GLP1R coding variants seen in human populations, with implications for GLP-1R agonist pharmacogenomics. CONCLUSIONS: Completely abolishing ß-arrestin recruitment improves the anti-hyperglycaemic effects of GLP-1R agonists in mice.

Impact of a dual glucose-dependent insulinotropic peptide/glucagon-like peptide-1 receptor agonist tirzepatide on heart rate among patients with type 2 diabetes: A systematic review and pairwise and network meta-analysis.

AIMS: To evaluate the impact of a dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide (TZP), and its potential dose-response effect, on heart rate. METHODS: Articles were searched from PubMed, Web of Science, Embase, Cochrane Library, and clinical trials registries (ClinicalTrials.gov) databases. Randomized controlled trials (RCTs) comparing TZP at doses of 5, 10 and 15 mg in adults with type 2 diabetes were included. Six study arms were summarized from original research (TZP 5, 10 and 15 mg, GLP-1 receptor agonists [GLP-1RAs], insulin, placebo). The GLP-1RA and non-GLP-1RA groups were combined to form a control group. Two reviewers independently extracted data and assessed the quality of each study. Mean differences (MDs) were calculated as effect estimates for continuous outcomes. Pairwise meta-analyses and network meta-analyses were conducted. The study protocol was prospectively registered (PROSPERO ID: CRD42023418551). RESULTS: Eight articles were included in this systematic review and meta-analysis. The mean baseline heart rate ranged from 65.2 to 75.7 beats per minute. Pairwise meta-analysis showed that, compared with combined the control group, there were significantly greater increases in heart rates in the TZP group (MD 1.82, 95% confidence interval [CI] 0.75, 2.89). Similar significant rises were identified when comparing TZP with GLP-1RAs and non-GLP-1RAs (GLP-1 RAs: MD 2.29, 95% CI 1.00, 3.59; non-GLP-1RAs: MD 1.58, 95% CI 0.26, 2.91). TZP 5 mg was associated with smaller increases in heart rates compared to TZP 10 mg and TZP 15 mg (TZP 10 mg: MD -0.97, 95% CI -1.79, -0.14; TZP 15 mg: MD -2.57, 95% CI -3.79, -1.35). TZP 10 mg increased heart rate less than TZP 15 mg (MD -1.5, 95% CI -2.38, -0.82). Network meta-analysis indicated that TZP 15 mg was associated with significant increases in heart rate compared with TZP 5 mg (MD 2.53, 95% CI 1.43, 3.62), TZP 10 mg (MD 1.44, 95% CI 0.35, 2.53), GLP-1RAs (MD 3.46, 95% CI 1.67, 5.25), insulin (MD 2.86, 95% CI 1.32, 4.41) and placebo (MD 2.96, 95% CI 1.36, 4.57). CONCLUSIONS: Our study showed not only that there was a greater increase in heart rate in the TZP group than in the control, GLP-1RA and non-GLP-1RA groups, but also that the 15-mg dose of TZP had the strongest impact on increasing heart rates compared with the other five inventions, with a TZP dose-response impact on heart rate. Further research on the effects of TZP treatment-related increases in heart rate is required.

Efficacy and safety of intragastric expandable oral capsules in adults with overweight or obesity: A randomized, double-blind, placebo-controlled trial.

AIM: This trial assessed the efficacy and safety of 2.24 g intragastric expandable capsules twice per day versus placebo for weight management in adults with overweight or obesity. METHODS: This double-blind, placebo-controlled study included adults with a body mass index of at least 24 kg/m2 and no more than 40 kg/m2 . In total, 280 participants were recruited from six hospitals in China and were assigned in a 1:1 ratio to receive 2.24 g oral intragastric expandable capsules or placebo for 24 weeks. Coprimary endpoints were the percentage change in body weight from baseline and the rate of weight reduction of ≥5%, assessed using both the full analysis set and per protocol set. RESULTS: At baseline, the mean body weight was 81.8 kg, and the mean body mass index was 29.4 kg/m2 . The mean body weight change at week 24 was -4.9% with intragastric expandable capsules versus -1.9% with placebo [estimated treatment difference (ETD) -3.0%, 95% confidence interval (CI) -4.1 to -1.9; p < .001] using the full analysis set and -6.1% versus -2.5% (ETD -3.6%, 95% CI -5.0 to -2.3; p < .001), respectively, using the per protocol set. The percentage of participants who had weight loss exceeding 5% was 45.0% in the intragastric expandable capsule group versus 19.7% in the placebo group (ETD 25.3%, 95% CI 14.7-35.9; p < .001) in the full analysis set and 55.9% versus 26.2% (ETD 29.6%, 95% CI 17.1-42.2; p < .001), respectively, in the per protocol set. Waist circumference significantly decreased at week 24 (intragastric expandable capsules vs. placebo: -5.6 ± 8.3 cm vs. -2.9 ± 4.8 cm; p = .003). The most common adverse events associated with the use of intragastric expandable capsules were gastrointestinal disorders (intragastric expandable capsule vs. placebo, 25.0% vs. 21.9%), and most were mild and transient. CONCLUSIONS: In this 24-week trial including participants with overweight or obesity, 2.24 g of intragastric expandable capsules twice daily led to a clinically meaningful reduction in body weight compared with placebo.

Risk of new-onset diabetes and efficacy of pharmacological weight loss therapy.

AIMS: To develop a clinical risk model to identify individuals at higher risk of developing new-onset diabetes and who might benefit more from weight loss pharmacotherapy. MATERIALS AND METHODS: A total of 21 143 patients without type 2 diabetes at baseline from two TIMI clinical trials of stable cardiovascular patients were divided into a derivation (~2/3) and validation (~1/3) cohort. The primary outcome was new-onset diabetes. Twenty-seven candidate risk variables were considered, and variable selection was performed using multivariable Cox regression. The final model was evaluated for discrimination and calibration, and for its ability to identify patients who experienced a larger benefit from the weight loss medication lorcaserin in terms of risk of new-onset diabetes. RESULTS: During a median (interquartile range) follow-up of 2.3 (1.8-2.7) years, new-onset diabetes occurred in 1013 patients (7.7%). The final model included five independent predictors (glycated haemoglobin, fasting glucose, age, body mass index, and triglycerides/high-density lipoprotein). The clinical risk model showed good discrimination (Harrell's C-indices 0.802, 95% confidence interval [CI] 0.788-0.817 and 0.807, 95% CI 0.788-0.826) in the derivation and validation cohorts. The calibration plot demonstrated adequate calibration (2.5-year area under the curve was 81.2 [79.1-83.5]). While hazard ratios for new-onset diabetes with a weight-loss therapy were comparable across risk groups (annual risks of <1%, 1%-5%, and >5%), there was a sixfold gradient in absolute risk reduction from lowest to highest risk group (p = 0.027). CONCLUSIONS: The developed clinical risk model effectively predicts new-onset diabetes, with potential implications for personalized patient care and therapeutic decision making.

Nicotinamide N-methyltransferase inhibition mitigates obesity-related metabolic dysfunction.

AIM: To assess the effects of a small-molecule nicotinamide N-methyltransferase (NNMT) inhibitor, 5A1MQ, on body composition, metabolic variables, fatty liver pathologies, and circulating biomarkers in diet-induced obese (DIO) mice, and characterize its plasma pharmacokinetics (PK) and tissue distribution in vivo. MATERIALS AND METHODS: DIO mice were administered vehicle or 5A1MQ once daily for 28 days. Longitudinal measures of body composition, blood glucose and plasma insulin levels, and terminal measures of liver histopathology and serum markers, were evaluated. Plasma and tissue PK were established in age- and strain-matched mice after intravenous, oral, and subcutaneous dosing of 5A1MQ. RESULTS: 5A1MQ treatment dose-dependently limited body weight and fat mass gains, improved oral glucose tolerance and insulin sensitivity, and suppressed hyperinsulinaemia in DIO mice. Liver histology from 5A1MQ-treated DIO mice showed attenuated hepatic steatosis and macrophage infiltration, and correspondingly reduced liver weight, size, and triglyceride levels. 5A1MQ treatment normalized circulating levels of alanine transaminase, aspartate transaminase, and ketone bodies, supporting an overall improvement in liver and metabolic functions. The pharmacodynamic effects of 5A1MQ were further corroborated by its high systemic exposure and effective distribution to metabolically active tissues, including adipose, muscle and liver, following subcutaneous dosing of mice. CONCLUSIONS: This work validates NNMT inhibition as a viable pharmacological approach to ameliorate metabolic imbalances and improve liver pathologies that develop with obesity.

Glucagon agonism in the treatment of metabolic diseases including type 2 diabetes mellitus and obesity.

Type 2 diabetes mellitus (T2DM) is associated with obesity and, therefore, it is important to target both overweight and hyperglycaemia. Glucagon plays important roles in glucose, amino acid and fat metabolism and may also regulate appetite and energy expenditure. These physiological properties are currently being exploited therapeutically in several compounds, most often in combination with glucagon-like peptide-1 (GLP-1) agonism in the form of dual agonists. With this combination, increases in hepatic glucose production and hyperglycaemia, which would be counterproductive, are largely avoided. In multiple randomized trials, the co-agonists have been demonstrated to lead to significant weight loss and, in participants with T2DM, even improved glycated haemoglobin (HbA1c) levels. In addition, significant reductions in hepatic fat content have been observed. Here, we review and discuss the studies so far available. Twenty-six randomized trials of seven different GLP-1 receptor (GLP-1R)/glucagon receptor (GCGR) co-agonists were identified and reviewed. GLP-1R/GCGR co-agonists generally provided significant weight loss, reductions in hepatic fat content, improved lipid profiles, insulin secretion and sensitivity, and in some cases, improved HbA1c levels. A higher incidence of adverse effects was present with GLP-1R/GCGR co-agonist treatment than with GLP-1 agonist monotherapy or placebo. Possible additional risks associated with glucagon agonism are also discussed. A delicate balance between GLP-1 and glucagon agonism seems to be of particular importance. Further studies exploring the optimal ratio of GLP-1 and glucagon receptor activation and dosage and titration regimens are needed to ensure a sufficient safety profile while providing clinical benefits.

Cagrilintide is not associated with clinically relevant QTc prolongation: A thorough QT study in healthy participants.

AIMS: The combination of cagrilintide and semaglutide (CagriSema) is being developed for the treatment of obesity and type 2 diabetes. The objective of this thorough QT study was to confirm that cagrilintide does not result in a clinically relevant prolongation in cardiac repolarization compared with placebo. MATERIALS AND METHODS: This was a double-blind study (NCT05804162) in which healthy participants were randomized to cagrilintide, administered as a once-weekly subcutaneous injection dose escalated to 4.5 mg, or a placebo. The primary end point was the time-matched change from baseline in Fridericia heart rate-corrected QT interval (QTcF) at 12-, 24-, 48- and 72 h after the last cagrilintide 4.5-mg dose. To conclude that cagrilintide does not induce a clinically relevant prolongation, the upper limit of the two-sided 90% confidence interval (CI) for the treatment difference at each of the four time points must fall below 10 ms. To establish QT assay sensitivity, participants in the placebo arms received a single 400-mg oral moxifloxacin dose as a positive control and moxifloxacin placebo in a nested cross-over fashion. RESULTS: A total of 105 participants received cagrilintide (n = 53) or placebo (n = 52). No clinically relevant QTcF prolongation occurred after the last cagrilintide 4.5-mg dose; the upper limits of the two-sided 90% CIs of the placebo-adjusted QTcF changes from baseline were below 10 ms at all time points. QT assay sensitivity was demonstrated with moxifloxacin as a positive control. CONCLUSIONS: Cagrilintide did not result in clinically relevant QTcF prolongation, indicating no increased risk of ventricular tachyarrhythmias.

Effect of oral semaglutide on energy intake, appetite, control of eating and gastric emptying in adults living with obesity: A randomized controlled trial.

AIM: To investigate the effects of once-daily oral semaglutide 50 mg on energy intake, appetite, control of eating and gastric emptying. METHODS: A clinical pharmacology, double-blind study was conducted in 61 adults with obesity randomized to once-daily oral semaglutide (dose-escalated to 50 mg) or placebo for 20 weeks. Energy intake was measured during an ad libitum lunch, and participant-reported appetite ratings and Control of Eating Questionnaire responses were assessed. Gastric emptying was measured using paracetamol absorption following a standardized breakfast. RESULTS: The relative change from baseline in ad libitum energy intake at week 20 (primary endpoint) was -39.2% points (95% confidence interval -59.0%, -19.4%) with semaglutide compared with placebo. Body weight was reduced by 9.8% with semaglutide and by 1.5% with placebo. Semaglutide reduced hunger, increased fullness and satiety, and was associated with fewer food cravings and better control of eating versus placebo. No statistically significant difference in gastric emptying was observed at week 20. CONCLUSIONS: In participants with obesity, once-daily oral semaglutide 50 mg reduced energy intake, body weight and appetite, and improved control of eating. There was no evidence of delayed gastric emptying at week 20, as measured through paracetamol absorption.

Oral or injectable semaglutide for the management of type 2 diabetes in routine care: A multicentre observational study comparing matched cohorts.

AIM: To investigate the real-world utilization and comparative clinical outcomes of injectable and oral semaglutide in individuals with type 2 diabetes (T2D) with the aim of enhancing understanding of the practical implications associated with choosing between these formulations. METHODS: New users of oral or injectable semaglutide were selected from a cohort of 14 079 initiators of glucagon-like peptide-1 receptor agonists. Propensity-score matching (PSM) was employed to create balanced groups, ensuring comparability. The analysis encompassed dose exposure, drug persistence, and clinical outcomes, including changes in glycated haemoglobin (HbA1c) and body weight, with up to 18 months' follow-up. RESULTS: We analysed two matched groups of 107 participants each, who comprised on average 63.6% men, aged 64 years, with diabetes duration of approximately 10 years, body mass index of 29 kg/m2 and HbA1c level of 7.7-7.8% (61-62 mmol/mol). The proportion of low, intermediate and high doses were similar with the oral and the injectable formulation. The change in HbA1c was similar between groups (-0.9% / -10 mmol/mol at 18 months) as was the proportion of individuals reaching HbA1c <6.5% (48 mmol/mol). The average change in body weight was similar in the two groups (-3.7 kg with injectable and -3.3 kg with oral at 18 months) but more new users of injectable semaglutide lost ≥5% body weight. Persistence on drug was longer with injectable than with oral semaglutide. CONCLUSION: In a real-world setting, improvements in HbA1c and body weight were similar after initiation of oral or injectable semaglutide. These results may be specific to the features of the matched cohorts under investigation, with limited generalizability to populations with different characteristics.

Investigating the potential non-authorized use of two different formulations of liraglutide in Europe: A real-world drug utilization study.

AIM: To assess the in-market use of Saxenda (liraglutide 3.0 mg) and Victoza (liraglutide 1.2 mg/1.8 mg) according to approved indications and posology. MATERIALS AND METHODS: This retrospective, non-interventional study was conducted at 41 sites from December 2016 to May 2019. Via medical record review, physicians at each site identified patients who had been prescribed Saxenda (Italy) or Victoza (Italy/Germany) within the 24 months following launch in each country. Pseudonymized data were abstracted on patient and site characteristics, indication for the prescription, posology and duration of usage. Adherence to the approved indications and posology, and to the Saxenda stopping rule, were assessed. No formal statistical analysis was performed. RESULTS: A total of 440 patients were prescreened and 225 (51.1%) were enrolled (Saxenda: N = 75, all in Italy; Victoza: N = 75 in Italy and N = 75 in Germany). In all, 96% (72/75) of Saxenda prescriptions, and 98.7% (148/150) of Victoza, were in accordance with the approved indications. Among the 40 patients treated with Saxenda for 16 weeks or longer, only two (5.0%) were confirmed as non-adherent to the stopping rule. Adherence could not be assessed in 23 (57.5%) patients because of missing body weight measurements. CONCLUSIONS: This retrospective, real-world post-authorization safety study provides reassurance that Saxenda and Victoza are primarily used according to the approved European label, thus their real-world utilization did not raise safety concerns.

Safety, tolerability, pharmacodynamics and pharmacokinetics following once-daily doses of BI 187004, an inhibitor of 11 beta-hydroxysteroid dehydrogenase-1, over 28 days in patients with type 2 diabetes mellitus and overweight or obesity.

AIMS: To study the oral 11 beta-hydroxysteroid dehydrogenase-1 (11ß-HSD1) inhibitor BI 187004 (NCT02150824), as monotherapy and in combination with metformin, versus placebo in patients with type 2 diabetes mellitus (T2DM) affected by overweight or obesity. MATERIALS AND METHODS: This Phase II, randomized controlled trial investigated multiple rising doses of BI 187004 as monotherapy (Arm 1: 20, 80 or 240 mg) and in combination with metformin (Arm 2: 240 mg), in adults with T2DM and a body mass index of 28-40 kg/m2 . RESULTS: In total, 103 patients (Arm 1: n = 62, Arm 2: n = 41) were included in this study. BI 187004 was rapidly absorbed and exposure increased approximately dose-dependently. Target engagement of 11ß-HSD1 was observed with near-full inhibition of 11ß-HSD1 in the liver [decreased (5α-tetrahydrocortisol + 5ß-tetrahydrocortisol)/tetrahydrocortisone ratio]; hypothalamic-pituitary-adrenal axis activation was also seen (increased total urinary corticosteroids). No clinically relevant changes from baseline with BI 187004 treatment were observed for bodyweight or meal tolerance test parameters, or in most efficacy endpoints testing glucose and lipid metabolism; a significant increase was observed in weighted mean plasma glucose (p < .05 for 80 and 240 mg BI 187004) but not fasting plasma glucose. Drug-related adverse events were reported for 14 patients (22.6%) in Arm 1 and 10 patients (24.4%) in Arm 2, most frequently headache, diarrhoea, flushing and dizziness. A dose-dependent increase in heart rate was seen with BI 187004 treatment. CONCLUSIONS: BI 187004 was generally well tolerated in patients with T2DM. Despite complete 11ß-HSD1 inhibition, no clinically relevant effects were observed with BI 187004.

The improved health utility of once-weekly subcutaneous semaglutide 2.4 mg compared with placebo in the STEP 1-4 obesity trials.

AIM: To assess health utility values in the Semaglutide Treatment Effect in People with obesity (STEP) 1-4 trials. MATERIALS AND METHODS: The STEP 1-4 phase 3a, 68-week, double-blind randomized controlled trials assessed the efficacy and safety of semaglutide 2.4 mg versus placebo in individuals with a body mass index (BMI) of 30 kg/m2 or higher or a BMI of 27 kg/m2 or higher and at least one comorbidity (STEP 1, 3 and 4), or a BMI of 27 kg/m2 or higher and type 2 diabetes (STEP 2). Patients received lifestyle intervention plus intensive behavioural therapy in STEP 3. Health-related quality of life was assessed using the Short Form 36-item Health Survey version 2 (SF-36v2) at baseline and week 68. Scores were converted into Short Form Six-Dimension version 2 (SF-6Dv2) utility scores or mapped onto the European Quality of Life Five-Dimension Three-Level (EQ-5D-3L) utility index using UK health utility weights. RESULTS: At week 68, semaglutide 2.4 mg was associated with minor health utility score improvements from baseline (all trials), while scores for placebo typically decreased. SF-6Dv2 treatment differences by week 68 for semaglutide 2.4 mg versus placebo were significant in STEP 1 and 4 (P ≤ .001), but not STEP 2 or 3. EQ-5D-3L treatment differences by week 68 for semaglutide 2.4 mg versus placebo were significant in STEP 1, 2 and 4 (P < .001 for all), but not STEP 3. CONCLUSIONS: Semaglutide 2.4 mg was associated with improvement in health utility scores compared with placebo, reaching statistical significance in STEP 1, 2 and 4.

New insights into the treatment of obesity.

Obesity is a chronic, progressive and relapsing disease with a rising global prevalence associated with increased morbidity and mortality and reduced quality of life. Treatment of obesity requires a comprehensive medical approach that includes behavioural interventions, pharmacotherapy and bariatric surgery. The degree of weight loss with all approaches is highly heterogeneous, and long-term weight maintenance remains challenging. For years, antiobesity medications have been limited in number, often delivering meagre efficacy and raising numerous safety concerns. Therefore, there is a need for the development of highly efficacious and safe new agents. Recent insights into the complex pathophysiology of obesity have increased our understanding of intervenable targets for pharmacotherapies to treat obesity and improve weight-related cardiometabolic complications, namely, type 2 diabetes, hyperlipidaemia and hypertension. As a result, novel potent therapies have emerged, such as semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA) recently approved for the treatment of obesity. Semaglutide 2.4 mg once weekly significantly reduces body weight by approximately 15%, with simultaneous improvement in cardiometabolic risk factors and physical functioning in people with obesity. Tirzepatide, the first dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1RA, has recently demonstrated that body weight reduction exceeding 20% in people with obesity and coupled with improved cardiometabolic measures is feasible. Thus, these novel agents promise to narrow the gap between the weight-loss effects of behaviour interventions, previous pharmacotherapies, and bariatric surgery. In this narrative review, we highlight established and emerging therapeutic treatments for long-term obesity management and position them in a framework according to their weight loss effects.

Cysteine-lowering treatment with mesna against obesity: Proof of concept and results from a human phase I, dose-finding study.

AIM: To investigate whether mesna-sodium-2-mercaptoethane sulfonate) can reduce diet-induced fat gain in mice, and to assess the safety of single ascending mesna doses in humans to find the dose associated with lowering of plasma tCys by at least 30%. METHODS: C3H/HeH mice were shifted to a high-fat diet ± mesna in drinking water; body composition was measured at weeks 0, 2 and 4. In an open, phase I, single ascending dose study, oral mesna (400, 800, 1200, 1600 mg) was administered to 17 men with overweight or obesity. Mesna and tCys concentrations were measured repeatedly for a duration of 48 hours postdosing in plasma, as well as in 24-hour urine. RESULTS: Compared with controls, mesna-treated mice had lower tCys and lower estimated mean fat mass gain from baseline (week 2: 4.54 ± 0.40 vs. 6.52 ± 0.36 g; week 4: 6.95 ± 0.35 vs. 8.19 ± 0.34 g; Poverall = .002), but similar lean mass gain. In men with overweight, mesna doses of 400-1600 mg showed dose linearity and were well tolerated. Mesna doses of 800 mg or higher decreased plasma tCys by 30% or more at nadir (4h post-dosing). With increasing mesna dose, tCys AUC0-12h decreased (Ptrend < .001), and urine tCys excretion increased (Ptrend = .004). CONCLUSIONS: Mesna reduces diet-induced fat gain in mice. In men with overweight, single oral doses of mesna (800-1600 mg) were well tolerated and lowered plasma tCys efficiently. The effect of sustained tCys-lowering by repeated mesna administration on weight loss in humans deserves investigation.

Tripeptide gut hormone infusion does not alter food preferences or sweet taste function in volunteers with obesity and prediabetes/diabetes but promotes restraint eating: A secondary analysis of a randomized single-blind placebo-controlled study.

AIMS: To investigate whether the elevation in postprandial concentrations of the gut hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM) and peptide YY (PYY) accounts for the beneficial changes in food preferences, sweet taste function and eating behaviour after Roux-en-Y gastric bypass (RYGB). MATERIALS AND METHODS: This was a secondary analysis of a randomized single-blind study in which we infused GLP-1, OXM, PYY (GOP) or 0.9% saline subcutaneously for 4 weeks in 24 subjects with obesity and prediabetes/diabetes, to replicate their peak postprandial concentrations, as measured at 1 month in a matched RYGB cohort (ClinicalTrials.gov NCT01945840). A 4-day food diary and validated eating behaviour questionnaires were completed. Sweet taste detection was measured using the method of constant stimuli. Correct sucrose identification (corrected hit rates) was recorded, and sweet taste detection thresholds (EC50s: half maximum effective concencration values) were derived from concentration curves. The intensity and consummatory reward value of sweet taste were assessed using the generalized Labelled Magnitude Scale. RESULTS: Mean daily energy intake was reduced by 27% with GOP but no significant changes in food preferences were observed, whereas a reduction in fat and increase in protein intake were seen post-RYGB. There was no change in corrected hit rates or detection thresholds for sucrose detection following GOP infusion. Additionally, GOP did not alter the intensity or consummatory reward value of sweet taste. A significant reduction in restraint eating, comparable to the RYGB group was observed with GOP. CONCLUSION: The elevation in plasma GOP concentrations after RYGB is unlikely to mediate changes in food preferences and sweet taste function after surgery but may promote restraint eating.

The importance of glucose-dependent insulinotropic polypeptide receptor activation for the effects of tirzepatide.

Tirzepatide is a unimolecular co-agonist of the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors recently approved for the treatment of type 2 diabetes by the US Food and Drug Administration and the European Medicine Agency. Tirzepatide treatment results in an unprecedented improvement of glycaemic control and lowering of body weight, but the contribution of the GIP receptor-activating component of tirzepatide to these effects is uncertain. In this review, we present the current knowledge about the physiological roles of the incretin hormones GLP-1 and GIP, their receptors, and previous results of co-targeting the two incretin hormone receptors in humans. We also analyse the molecular pharmacological, preclinical and clinical effects of tirzepatide to discuss the role of GIP receptor activation for the clinical effects of tirzepatide. Based on the available literature on the combination of GLP-1 and GIP receptor activation, tirzepatide does not seem to have a classical co-activating mode of action in humans. Rather, in vitro studies of the human GLP-1 and GIP receptors reveal a biased GLP-1 receptor activation profile and GIP receptor downregulation. Therefore, we propose three hypotheses for the mode of action of tirzepatide, which can be addressed in future, elaborate clinical trials.

A simple yet multifaceted 90 years old, evergreen enzyme: Carbonic anhydrase, its inhibition and activation.

Advances in the carbonic anhydrase (CA, EC 4.2.1.1) research over the last three decades are presented, with an emphasis on the deciphering of the activation mechanism, the development of isoform-selective inhibitors/ activators by the tail approach and their applications in the management of obesity, hypoxic tumors, neurological conditions, and as antiinfectives.

Examining the evidence for weight management in individuals with type 2 diabetes.

The obesity epidemic has been linked to the worsening diabetes epidemic. Despite this, weight reduction for individuals with obesity is seen as a secondary, or even tertiary, consideration in the treatment of type 2 diabetes (T2D). The aim of this review is to examine the benefits of weight management in individuals with T2D. A literature review of current available published data on the benefits of weight reduction in individuals with T2D was conducted. In individuals with T2D who have obesity or overweight, modest and sustained weight reduction results in improvement in glycaemic control and decreased utilization of glucose-lowering medication. A total body weight loss of 5% or higher reduces HbA1c levels and contributes to mitigating risk factors of cardiovascular disease, such as hyperlipidaemia and hypertension, as well as other disease-related complications of obesity. Progressive improvements in glycaemic control and cardiometabolic risk factors can occur when the total body weight loss increases to 10% or more. In the approach to treating patients with T2D and obesity, prioritizing weight management and the use of therapeutics that offer glycaemic control as well as the additional weight loss should be emphasized given their potential to attenuate the progression and severity of T2D.