Glucagon-like peptide (GLP)-1 is a hormone released by enteroendocrine L-cells after food ingestion. L-cells express various receptors for nutrient sensing including G protein-coupled receptors (GPRs). Intestinal epithelial cells near the lumen have a lower O2 tension than at the base of the crypts, which leads to hypoxia in L-cells. We hypothesized that hypoxia affects nutrient-stimulated GLP-1 secretion from the enteroendocrine cell line STC-1, the most commonly used model. In this study, we investigated the effect of hypoxia (1% O2) on alpha-linolenic acid (αLA) stimulated GLP-1 secretion and their receptor expressions. STC-1 cells were incubated for 12 h under hypoxia (1% O2) and treated with αLA to stimulate GLP-1 secretion. 12 h of hypoxia did not change basal GLP-1 secretion, but significantly reduced nutrient (αLA) stimulated GLP-1 secretion. In normoxia, αLA (12.5 μM) significantly stimulated (~ 5 times) GLP-1 secretion compared to control, but under hypoxia, GLP-1 secretion was reduced by 45% compared to normoxia. αLA upregulated GPR120, also termed free fatty acid receptor 4 (FFAR4), expressions under normoxia as well as hypoxia. Hypoxia downregulated GPR120 and GPR40 expression by 50% and 60%, respectively, compared to normoxia. These findings demonstrate that hypoxia does not affect the basal GLP-1 secretion but decreases nutrient-stimulated GLP-1 secretion. The decrease in nutrient-stimulated GLP-1 secretion was due to decreased GPR120 and GPR40 receptors expression. Changes in the gut environment and inflammation might contribute to the hypoxia of the epithelial and L-cells.

OBJECTIVE: Although metformin is widely used for treatment of type 2 diabetes (T2D), its glucose-lowering mechanism remains unclear. Using the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) antagonist exendin(9-39)NH2, we tested the hypothesis that postprandial GLP-1-mediated effects contribute to the glucose-lowering potential of metformin in T2D.
METHODS: In a randomized, placebo-controlled, double-blind, crossover study, 15 individuals with T2D (median HbA1c 50 mmol/mol [6.7%], body mass index 30.1 kg/m2, age 71 years) underwent, in randomized order, 14 days of metformin and placebo treatment, respectively. Each treatment period was preceded by 14 days without any glucose-lowering medicine and concluded by two 4 h mixed meal tests performed in randomized order and separated by >24 h with either continuous intravenous exendin(9-39)NH2 or saline infusion.
RESULTS: Compared to placebo, metformin treatment lowered fasting plasma glucose (mean of differences [MD] 1.4 mmol/L × min [95% CI 0.8-2.0]) as well as postprandial plasma glucose excursions during both saline infusion (MD 186 mmol/L × min [95% CI 64-307]) and exendin(9-39)NH2 infusion (MD 268 mmol/L × min [95% CI 108-427]). The metformin-induced improvement in postprandial glucose tolerance was unaffected by GLP-1R antagonization (MD 82 mmol/L × min [95% CI -6564-170]). Metformin treatment increased fasting plasma GLP-1 (MD 1.7 pmol/L × min [95% CI 0.39-2.9]) but did not affect postprandial GLP-1 responses (MD 820 pmol/L × min [95% CI -1750-111]).
CONCLUSIONS: Using GLP-1R antagonization, we could not detect GLP-1-mediated postprandial glucose-lowering effect of metformin in individuals with T2D. We show that 2 weeks of metformin treatment increases fasting plasma GLP-1, which may contribute to metformin\'s beneficial effect on fasting plasma glucose in T2D. Trial registration: Clinicaltrials.gov NCT03246451.

OBJECTIVE: This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD).
METHODS: Subjects with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus (T2DM). The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment.
RESULTS: 94 subjects were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of subjects had T2DM. At Week 12, relative reductions in LFC from baseline were (1.2 mg) 46.6% [95% CI -63.7 to -29.6], (1.8 mg) 68.5% [95% CI -84.4 to -52.5], and (2.4 mg) 57.1% [95% CI -76.1 to -38.1] versus 4.4% [95% CI -20.2 to 11.3] in placebo subjects (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of subjects achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events.
CONCLUSIONS: In subjects with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo.
UNASSIGNED: MASLD, and MASH, are strongly associated with overweight and obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor (GCGR) agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content (LFC) reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/GCGR agonist, to significantly reduce LFC, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both MASH and obesity.
BACKGROUND: NCT05006885.

UNASSIGNED: Minimizing postprandial glucose response is an important goal for overall diabetes management. Diabetes-specific nutritional shakes (DSNS) have been clinically shown to minimize postprandial glucose response in people with type 2 diabetes (T2DM) compared to high-glycemic foods. However, it is unknown how a high-protein, low-fat DSNS impacts the GLP-1 response.
UNASSIGNED: We tested the postprandial glucose, insulin, and GLP-1 response to a high-protein, low-fat diabetes-specific nutritional shake (DSNS-HP) compared to isocaloric instant oatmeal (IOM) in a randomized, controlled, crossover study in adults with T2DM (n = 24). Participants were randomly selected to receive IOM or DSNS-HP on two test days. Glucose, insulin, and total GLP-1 concentration were measured at baseline and 15, 30, 45, 60, 90, 120, 180, and 240 min postprandially.
UNASSIGNED: Compared to IOM, the glucose-positive area under the curve (pAUC) was significantly lower (P = .021). DSNS-HP significantly increased GLP-1 pAUC response by 213% (P <.001) with a corresponding increase in insulin pAUC (P = .033) compared to IOM.
UNASSIGNED: A high-protein, low-fat DSNS leads to favorable changes in GLP-1 response and is a suitable option to minimize blood glucose response in people with type 2 diabetes.

Introduction Recent randomized controlled trials (RCTs) have shown the great efficacy of semaglutide in achieving significant weight loss in overweight and obese adults. However, real-world data about its effectiveness are still limited. This study evaluated the effectiveness and adverse events of semaglutide for weight management in a real-life setting, excluding patients with diabetes mellitus (DM). Methods This is a retrospective chart review of 40 overweight or obese individuals with a median age of 47 years, weight of 111.7 kg, and body mass index (BMI) of 39.7 kg/m2 who were prescribed semaglutide for weight management. Results After three months of semaglutide administration, the median weight reduction was 7.4 kg (6.6% of the baseline weight), with 28 (70%) and eight patients (20%) achieving greater than 5% (5.6 kg) and 10% (11.2 kg) weight loss, respectively. Among 25 patients with six-month data, 22 (88%), 17 (68%), and eight (32%) patients exceeded 5% (5.6 kg), 10% (11.2 kg), and 15% (16.8 kg) weight loss, respectively. The maintenance semaglutide dose was 1 mg in 16 cases and 2 mg in nine cases, leading to a similar weight loss of 13.6% (14.9 kg) and 12.8% (14 kg), respectively. Relatively low response rates were observed in males, with seven responders out of 12 (58.4%) compared to 24 out of 28 (85.8%) in females (P value = 0.057), and in five out of nine (55.6%) among those with a history of psychiatric disease. The rate of adverse events was 26 out of 40 patients (65%), mostly mild to moderate and of short duration, leading to discontinuation in only a single case (2.5%). Conclusion This retrospective study demonstrated the significant effectiveness of semaglutide for weight loss, even at lower than approved maintenance doses, combined with a good safety profile. Therefore, semaglutide may dramatically change the landscape of obesity treatment.

BACKGROUND: Oral semaglutide improves cardiovascular risk factors in people with type 2 diabetes (T2D) in clinical trials, though real-world evidence is limited. We aimed to determine the real-world impact of oral semaglutide on routinely collected clinical data in our practice.
METHODS: People with T2D initiated on oral semaglutide in secondary care diabetes clinics at two hospital sites in Wales (United Kingdom) were included. Data were collected on reasons for oral semaglutide initiation and changes in bodyweight, blood pressure, glycemic control, and lipid profiles over follow-up at 3-6 months, and at 6-12 months. Data were collected to determine the safety of oral semaglutide.
RESULTS: Seventy-six patients were included, with a median age 59.3 [51.4-67.6] years, and 38 (50.0%) patients were female. The most common reasons for oral semaglutide were need for weight loss and improved glycemia (69.8%), and improved glycemia alone (25.0%). Oral semaglutide associated with significantly reduced bodyweight (- 3.3 kg), body mass index (BMI) (- 0.9 kg/m2), glycated hemoglobin (HbA1c) (- 11 mmol/mol), and total cholesterol (- 0.4 mmol/l) by 3-6 months follow-up. At 6-12 months, there was a significant reduction in systolic blood pressure (- 7.0 mmHg), in addition to sustained reductions in other metabolic parameters. By 12 months, 18 (23.6%) patients had discontinued the drug, largely resulting from gastrointestinal disturbance, but there were no serious events in this cohort.
CONCLUSIONS: Oral semaglutide was effective in improving cardiovascular risk factors in this real-world population living with T2D, and no serious events were identified related to oral semaglutide in this patient group.

BACKGROUND: The role of glucagon-like peptide-1 (GLP-1) in type 2 diabetes (T2D) and obesity is not fully understood.
OBJECTIVE: We investigate the association of cardiometabolic, diet, and lifestyle parameters on fasting and postprandial GLP-1 in people at risk of, or living with, T2D.
METHODS: We analyzed cross-sectional data from the two Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) cohorts, cohort 1 (n = 2127) individuals at risk of diabetes; cohort 2 (n = 789) individuals with new-onset T2D.
RESULTS: Our multiple regression analysis reveals that fasting total GLP-1 is associated with an insulin-resistant phenotype and observe a strong independent relationship with male sex, increased adiposity, and liver fat, particularly in the prediabetes population. In contrast, we showed that incremental GLP-1 decreases with worsening glycemia, higher adiposity, liver fat, male sex, and reduced insulin sensitivity in the prediabetes cohort. Higher fasting total GLP-1 was associated with a low intake of wholegrain, fruit, and vegetables in people with prediabetes, and with a high intake of red meat and alcohol in people with diabetes.
CONCLUSIONS: These studies provide novel insights into the association between fasting and incremental GLP-1, metabolic traits of diabetes and obesity, and dietary intake, and raise intriguing questions regarding the relevance of fasting GLP-1 in the pathophysiology T2D.

BACKGROUND: Appetite hormones are considered a promising target in fighting obesity as impaired appetite hormone levels have already been associated with obesity. However, further insights in the drivers of appetite hormone levels are needed.
OBJECTIVE: In this study, we investigated the associations of fasting appetite hormone levels with lifestyle and environmental exposures in children and adolescents.
METHODS: A total of 534 fasting blood samples were collected from children and adolescents (4-16y,50% boys) and appetite hormone levels (glucagon-like peptide-1 (GLP-1), peptide YY (PYY), pancreatic polypeptide (PP), leptin and ghrelin) were measured. Exposures included dietary quality (fiber-rich food intake, sugar propensity, fat propensity), psychosocial stress (happiness, negative emotions, negative life events and emotional problems), sleep duration, physical activity and environmental quality (long term black carbon (BC), particulate matter <2.5 μM (PM2.5), nitrogen dioxide (NO2) exposure, and green space in a 100 m and 2000 m radius around the residence). A multi-exposure score was calculated to combine all the exposures at study in one measure. Associations of individual exposures and multi-exposure score with appetite hormone levels were evaluated using linear mixed regression models adjusting for sex, age, socioeconomic status, waist-to-height ratio and multiple testing.
RESULTS: GLP-1 was associated with air pollution exposure (NO2 β* = -0.13, BC β* = -0.15, PM2.5 β* = -0.16, all p < 0.001). Leptin was associated with green space in a 100 m radius around the residence (β* = -0.11; p = 0.002). Ghrelin was associated with negative emotions (active ghrelin β* = -0.16; p = 0.04, total ghrelin β* = -0.23; p = 0.0051) and happiness (active ghrelin β* = 0.25; p < 0.001, total ghrelin β* = 0.26; p < 0.001). Furthermore, total ghrelin levels were associated with the multi-exposure score, reflecting unhealthy exposures and lifestyle (β* = -0.22; p = 0.036).
CONCLUSIONS: Our findings provide new insights into the associations of exposures with appetite hormone levels, which are of high interest for preventive obesity research. Further research is crucial to reveal the underlying mechanisms of the observed associations.

OBJECTIVE: According to preclinical evidence, GLP-1 receptor may be an actionable target in neurodegenerative disorders, including Alzheimer\'s disease (AD). Previous clinical trials of GLP-1 receptor agonists were conducted in patients with early AD, yielding mixed results. The aim was to assess in a proof-of-concept study whether slow-release exenatide, a long-acting GLP-1 agonist, can benefit the cognitive performance of people with mild cognitive impairment (MCI).
METHODS: Thirty-two (16 females) patients were randomized to either slow-release exenatide (n = 17; 2 mg s.c. once a week) or no treatment (n = 15) for 32 weeks. The primary endpoint was the change in ADAS-Cog11 cognitive test score at 32 weeks vs baseline. Secondary endpoints herein reported included additional cognitive tests and plasma readouts of GLP-1 receptor engagement. Statistical analysis was conducted by intention to treat.
RESULTS: No significant between-group effects of exenatide on ADAS-Cog11 score (p = 0.17) were detected. A gender interaction with treatment was observed (p = 0.04), due to worsening of the ADAS-Cog11 score in women randomized to exenatide (p = 0.018), after correction for age, scholar level, dysglycemia, and ADAS-Cog score baseline value. Fasting plasma glucose (p = 0.02) and body weight (p = 0.03) decreased in patients randomized to exenatide.
CONCLUSIONS: In patients with MCI, a 32-week trial with slow-release exenatide had no beneficial effect on cognitive performance.
BACKGROUND: NCT03881371, registered on 21 July, 2016.

The aim of this study was to assess whether adding Ca2+ to aggregate or native forms of β-lactoglobulin alters gut hormone secretion, gastric emptying rates and energy intake in healthy men and women. Fifteen healthy adults (mean ± sd: 9M/6F, age: 24 ± 5 years) completed four trials in a randomised, double-blind, crossover design. Participants consumed test drinks consisting of 30 g of β-lactoglobulin in a native form with (NATIVE + MINERALS) and without (NATIVE) a Ca2+-rich mineral supplement and in an aggregated form both with (AGGREG + MINERALS) and without the mineral supplement (AGGREG). Arterialised blood was sampled for 120 min postprandially to determine gut hormone concentrations. Gastric emptying was determined using 13C-acetate and 13C-octanoate, and energy intake was assessed with an ad libitum meal at 120 min. A protein × mineral interaction effect was observed for total glucagon-like peptide-1 (GLP-1TOTAL) incremental AUC (iAUC; P < 0·01), whereby MINERALS + AGGREG increased GLP-1TOTAL iAUC to a greater extent than AGGREG (1882 ± 603 v. 1550 ± 456 pmol·l-1·120 min, P < 0·01), but MINERALS + NATIVE did not meaningfully alter the GLP-1 iAUC compared with NATIVE (1669 ± 547 v. 1844 ± 550 pmol·l-1·120 min, P = 0·09). A protein × minerals interaction effect was also observed for gastric emptying half-life (P < 0·01) whereby MINERALS + NATIVE increased gastric emptying half-life compared with NATIVE (83 ± 14 v. 71 ± 8 min, P < 0·01), whereas no meaningful differences were observed between MINERALS + AGGREG v. AGGREG (P = 0·70). These did not result in any meaningful changes in energy intake (protein × minerals interaction, P = 0·06). These data suggest that the potential for Ca2+ to stimulate GLP-1 secretion at moderate protein doses may depend on protein form. This study was registered at clinicaltrials.gov (NCT04659902).