Effect of ghrelin on glucose tolerance, gut hormones, appetite, and food intake after sleeve gastrectomy.

Ghrelin is an appetite-stimulating hormone secreted from the gastric mucosa in the fasting state, and secretion decreases in response to food intake. After sleeve gastrectomy (SG), plasma concentrations of ghrelin decrease markedly. Whether this affects appetite and glucose tolerance postoperatively is unknown. We investigated the effects of ghrelin infusion on appetite and glucose tolerance in individuals with obesity before and 3 mo after SG. Twelve participants scheduled for SG were included. Before and 3 mo after surgery, a mixed-meal test followed by an ad libitum meal test was performed with concomitant infusions of acyl-ghrelin (1 pmol/kg/min) or placebo. Infusions began 60 min before meal intake to reach a steady state before the mixed-meal and were continued throughout the study day. Two additional experimental days with 0.25 pmol/kg/min and 10 pmol/kg/min of acyl-ghrelin infusions were conducted 3 mo after surgery. Both before and after SG, postprandial glucose concentrations increased dose dependently during ghrelin infusions compared with placebo. Ghrelin infusions inhibited basal and postprandial insulin secretion rates, resulting in lowered measures of ß-cell function, but no effect on insulin sensitivity was seen. Ad libitum meal intake was unaffected by the administration of ghrelin. In conclusion, ghrelin infusion increases postprandial plasma glucose concentrations and impairs ß-cell function before and after SG but has no effect on ad libitum meal intake. We speculate that the lower concentration of ghrelin after SG may impact glucose metabolism following this procedure.NEW & NOTEWORTHY Ghrelin's effect on glucose tolerance and food intake following sleeve gastrectomy (SG) was evaluated. Acyl-ghrelin was infused during a mixed-meal and ad libitum meals before and 3 mo after surgery. Postprandial glucose concentrations increased during ghrelin infusions, both before and after surgery, while insulin production was inhibited. However, ad libitum meal intake did not differ during ghrelin administration compared with placebo. The decreased ghrelin concentration following SG may contribute to the glycemic control after surgery.

Healthy Weight Loss Maintenance with Exercise, Liraglutide, or Both Combined.

BACKGROUND: Weight regain after weight loss is a major problem in the treatment of persons with obesity. METHODS: In a randomized, head-to-head, placebo-controlled trial, we enrolled adults with obesity (body-mass index [the weight in kilograms divided by the square of the height in meters], 32 to 43) who did not have diabetes. After an 8-week low-calorie diet, participants were randomly assigned for 1 year to one of four strategies: a moderate-to-vigorous-intensity exercise program plus placebo (exercise group); treatment with liraglutide (3.0 mg per day) plus usual activity (liraglutide group); exercise program plus liraglutide therapy (combination group); or placebo plus usual activity (placebo group). End points with prespecified hypotheses were the change in body weight (primary end point) and the change in body-fat percentage (secondary end point) from randomization to the end of the treatment period in the intention-to-treat population. Prespecified metabolic health-related end points and safety were also assessed. RESULTS: After the 8-week low-calorie diet, 195 participants had a mean decrease in body weight of 13.1 kg. At 1 year, all the active-treatment strategies led to greater weight loss than placebo: difference in the exercise group, -4.1 kg (95% confidence interval [CI], -7.8 to -0.4; P = 0.03); in the liraglutide group, -6.8 kg (95% CI, -10.4 to -3.1; P<0.001); and in the combination group, -9.5 kg (95% CI, -13.1 to -5.9; P<0.001). The combination strategy led to greater weight loss than exercise (difference, -5.4 kg; 95% CI, -9.0 to -1.7; P = 0.004) but not liraglutide (-2.7 kg; 95% CI, -6.3 to 0.8; P = 0.13). The combination strategy decreased body-fat percentage by 3.9 percentage points, which was approximately twice the decrease in the exercise group (-1.7 percentage points; 95% CI, -3.2 to -0.2; P = 0.02) and the liraglutide group (-1.9 percentage points; 95% CI, -3.3 to -0.5; P = 0.009). Only the combination strategy was associated with improvements in the glycated hemoglobin level, insulin sensitivity, and cardiorespiratory fitness. Increased heart rate and cholelithiasis were observed more often in the liraglutide group than in the combination group. CONCLUSIONS: A strategy combining exercise and liraglutide therapy improved healthy weight loss maintenance more than either treatment alone. (Funded by the Novo Nordisk Foundation and others; EudraCT number, 2015-005585-32; ClinicalTrials.gov number, NCT04122716.).

Change in abdominal obesity after colon cancer surgery - effects of left-sided and right-sided colonic resection.

BACKGROUND: Excess abdominal visceral adipose tissue (VAT) is associated with metabolic diseases and poor survival in colon cancer (CC). We assessed the impact of different types of CC surgery on changes in abdominal fat depots. MATERIAL AND METHODS: Computed tomography (CT)-scans performed preoperative and 3 years after CC surgery were analyzed at L3-level for VAT, subcutaneous adipose tissue (SAT) and total adipose tissue (TAT) areas. We assessed changes in VAT, SAT, TAT and VAT/SAT ratio after 3 years and compared the changes between patients who had undergone left-sided and right-sided colonic resection in the total population and in men and women separately. RESULTS: A total of 134 patients with stage I-III CC undergoing cancer surgery were included. Patients who had undergone left-sided colonic resection had after 3 years follow-up a 5% (95% CI: 2-9%, p < 0.01) increase in abdominal VAT, a 4% (95% CI: 2-6%, p < 0.001) increase in SAT and a 5% increase (95% CI: 2-7%, p < 0.01) in TAT. Patients who had undergone right-sided colonic resection had no change in VAT, but a 6% (95% CI: 4-9%, p < 0.001) increase in SAT and a 4% (95% CI: 1-7%, p < 0.01) increase in TAT after 3 years. Stratified by sex, only males undergoing left-sided colonic resection had a significant VAT increase of 6% (95% CI: 2-10%, p < 0.01) after 3 years. CONCLUSION: After 3 years follow-up survivors of CC accumulated abdominal adipose tissue. Notably, those who underwent left-sided colonic resection had increased VAT and SAT, whereas those who underwent right-sided colonic resection demonstrated solely increased SAT.

The role of empagliflozin-induced metabolic changes for cardiac function in patients with type 2 diabetes. A randomized cross-over magnetic resonance imaging study with insulin as comparator.

BACKGROUND: Metabolic effects of empagliflozin treatment include lowered glucose and insulin concentrations, elevated free fatty acids and ketone bodies and have been suggested to contribute to the cardiovascular benefits of empagliflozin treatment, possibly through an improved cardiac function. We aimed to evaluate the influence of these metabolic changes on cardiac function in patients with T2D. METHODS: In a randomized cross-over design, the SGLT2 inhibitor empagliflozin (E) was compared with insulin (I) treatment titrated to the same level of glycemic control in 17 patients with type 2 diabetes, BMI of > 28 kg/m2, C-peptide > 500 pM. Treatments lasted 5 weeks and were preceded by 3-week washouts (WO). At the end of treatments and washouts, cardiac diastolic function was determined with magnetic resonance imaging from left ventricle early peak-filling rate and left atrial passive emptying fraction (primary and key secondary endpoints); systolic function from left ventricle ejection fraction (secondary endpoint). Coupling between cardiac function and fatty acid concentrations, was studied on a separate day with a second scan after reduction of plasma fatty acids with acipimox. Data are Mean ± standard error. Between treatment difference (ΔT: E-I) and treatments effects (ΔE: E-WO or ΔI: I -WO) were evaluated using Students' t-test or Wilcoxon signed rank test as appropriate. RESULTS: Glucose concentrations were similar, fatty acids, ketone bodies and lipid oxidation increased while insulin concentrations decreased on empagliflozin compared with insulin treatment. Cardiac diastolic and systolic function were unchanged by either treatment. Acipimox decreased fatty acids with 35% at all visits, and this led to reduced cardiac diastolic (ΔT: -51 ± 22 ml/s (p < 0.05); ΔE: -33 ± 26 ml/s (ns); ΔI: 37 ± 26 (ns, p < 0.05 vs ΔE)) and systolic function (ΔT: -3 ± 1% (p < 0.05); ΔE: -3 ± 1% (p < 0.05): ΔI: 1 ± 2 (ns, ns vs ΔE)) under chronotropic stress during empagliflozin compared to insulin treatment. CONCLUSIONS: Despite significant metabolic differences, cardiac function did not differ on empagliflozin compared with insulin treatment. Impaired cardiac function during acipimox treatment, could suggest greater cardiac reliance on lipid metabolism for proper function during empagliflozin treatment in patients with type 2 diabetes. TRIAL REGISTRATION: EudraCT 2017-002101-35, August 2017.

Canagliflozin or acarbose versus placebo to ameliorate post-bariatric hypoglycaemia - The HypoBar I randomized clinical trial protocol.

INTRODUCTION: Post-bariatric hypoglycaemia (PBH) is a rare yet disabling clinical condition, mostly reported after Roux-en-Y gastric bypass (RYGB) surgery. RYGB is one of the most widely used and effective bariatric procedures. The pathophysiology of PBH remains unclear, and treatment options are limited in effectiveness and/or carry significant side effects. Acarbose slows carbohydrates digestion and absorption and is generally considered first-line pharmacological treatment for PBH but its gastrointestinal side effects limit patient compliance. Canagliflozin inhibits intestinal and renal sodium-dependent glucose absorption and reduces postprandial excursions of glucose, insulin and incretins after RYGB - effects that could be beneficial in ameliorating PBH. AIMS: The trial aims to investigate how blood glucose levels are affected during daily living in subjects with PBH during treatment with canagliflozin or acarbose compared with placebo, and to study the meal-induced entero-endocrine mechanisms implied in the treatment responses. METHODS: In a double-blinded, randomized, crossover clinical trial, HypoBar I will investigate the effectiveness in reducing the risk of PBH, safety, ambulatory glucose profile and entero-endocrine responses when PBH is treated with canagliflozin 300 mg twice daily during a 4-week intervention period, compared with acarbose 50 mg thrice daily or placebo. ETHICS AND DISSEMINATION: HypoBar I is approved by the Local regulatory entities. Results will be published in peer-reviewed journals. CONCLUSION: If effective, well-tolerated and safe, canagliflozin could be a novel treatment for people with PBH. HypoBar I might also unravel new mechanisms underlying PBH, potentially identifying new treatment targets. TRIAL REGISTRATION: EudraCT number 2022-000157-87.

Liraglutide enhances insulin secretion and prolongs the remission period in adults with newly diagnosed type 1 diabetes (the NewLira study): A randomized, double-blind, placebo-controlled trial.

AIM: To test the effect of the glucagon-like peptide-1 receptor agonist, liraglutide, on residual beta-cell function in adults with newly diagnosed type 1 diabetes. MATERIALS AND METHODS: In a multicentre, double-blind, parallel-group trial, adults with newly diagnosed type 1 diabetes and stimulated C-peptide of more than 0.2 nmol/L were randomized (1:1) to 1.8-mg liraglutide (Victoza) or placebo once daily for 52 weeks with 6 weeks of follow-up with only insulin treatment. The primary endpoint was the between-group difference in C-peptide area under the curve (AUC) following a liquid mixed-meal test after 52 weeks of treatment. RESULTS: Sixty-eight individuals were randomized. After 52 weeks, the 4-hour AUC C-peptide response was maintained with liraglutide, but decreased with placebo (P = .002). Six weeks after end-of-treatment, C-peptide AUCs were similar for liraglutide and placebo. The average required total daily insulin dose decreased from 0.30 to 0.23 units/kg/day with liraglutide, but increased from 0.29 to 0.43 units/kg/day in the placebo group at week 52 (P < .001). Time without the need for insulin treatment was observed in 13 versus two patients and lasted for 22 weeks (from 3 to 52 weeks) versus 6 weeks (from 4 to 8 weeks) on average for liraglutide and placebo, respectively. Patients treated with liraglutide had fewer episodes of hypoglycaemia compared with placebo-treated patients. The adverse events with liraglutide were predominantly gastrointestinal and transient. CONCLUSIONS: Treatment with liraglutide improves residual beta-cell function and reduces the dose of insulin during the first year after diagnosis. Beta-cell function was similar at 6 weeks postliraglutide treatment.

Kinetics of insulin and C-peptide and estimation of prehepatic insulin secretion rates after intravenous glucose stimulation using arterial versus venous blood sampling in healthy males.

An intravenous glucose-infusion of 0.3 g glucose per Kg body weight was administered over 1 min in nine healthy males with simultaneous blood sampling from the hepatic vein, femoral artery and a peripheral vein. Insulin secretion rates (ISR) were determined by the Eaton method and the ISEC method using C-peptide concentrations from arterial and peripheral venous blood. First phase (0-10 min), second phase (10-60 min), and total insulin secretion (0-60 min) were calculated as the incremental areas (iAUC) above baseline. The primary endpoint was first phase insulin response. The first phase insulin response in artery and venous blood did not differ with the Eaton method (p = 0.25), but was significantly greater with the ISEC method in arterial compared with venous blood (p < 0.05). The first phase insulin responses did not differ between methods in artery (p = 0.73) or venous blood (p = 0.73). The first phase responses of insulin and C-peptide were significant higher in the hepatic vein compared with those in the artery (p < 0.05) and peripheral vein (p < 0.05) but did not differ significantly between the artery compared with the peripheral vein for insulin (p = 0.09) or C-peptide (p = 0.26). Prehepatic insulin secretion rates did not differ between the Eaton and ISEC methods, but with the ISEC method the first phase insulin response was significantly greater in arterial compared with venous blood. The first phase insulin response differs when calculated from plasma insulin or C-peptide and depends on sample sites.

The effects of postprandial exercise and meal glycemic index on plasma glucose and glucoregulatory hormone responses after Roux-en-Y gastric bypass.

Postprandial hypoglycemia is a complication of Roux-en-Y gastric bypass (RYGB), but the effects of postprandial exercise and meal glycemic index (GI) on postprandial glucose and glucoregulatory hormone responses are unknown. Ten RYGB-operated and 10 age and weight-matched unoperated women completed four test days in random order ingesting mixed meals with high GI (HGI, GI = 93) or low GI (LGI, GI = 54), but matched on energy and macronutrient content. Ten minutes after meal completion, participants rested or cycled for 30 min at 70% of maximum oxygen uptake (V̇o2max). Blood was collected for 4 h. Postprandial exercise did not lower plasma nadir glucose in RYGB after HGI (HGI/rest 3.7 ± 0.5 vs. HGI/Ex 4.1 ± 0.4 mmol/L, P = 0.070). Replacing HGI with LGI meals raised glucose nadir in RYGB (LGI/rest 4.1 ± 0.5 mmol/L, P = 0.034) and reduced glucose excursions (Δpeak-nadir) but less so in RYGB (-14% [95% CI: -27; -1]) compared with controls (-33% [-51; -14]). Insulin responses mirrored glucose concentrations. Glucagon-like peptide 1 (GLP-1) responses were greater in RYGB versus controls, and higher with HGI versus LGI. Glucose-dependent insulinotropic polypeptide (GIP) responses were greater after HGI versus LGI in both groups. Postexercise glucagon responses were lower in RYGB than controls, and noradrenaline responses tended to be lower in RYGB, whereas adrenaline responses were similar between groups. In conclusion, moderate intensity cycling shortly after meal intake did not increase the risk of postprandial hypoglycemia after RYGB. The low GI meal increased nadir glucose and reduced glucose excursions compared with the high GI meal. RYGB participants had lower postexercise glucagon responses compared with controls.NEW & NOTEWORTHY We investigate the effect of moderate exercise after a high or a low glycemic index meal on nadir glucose and glucoregulatory hormones in gastric bypass-operated individuals and in matched unoperated controls. Cycling shortly after meal intake did not increase the risk of hypoglycemia in operated individuals. The low glycemic index meal increased glucose nadir and reduced excursions compared with the high glycemic index meal. Operated individuals had lower postexercise glucagon responses compared with controls.

Primary weight loss failure after Roux-en-Y gastric bypass is characterized by impaired gut-hormone mediated regulation of food intake.

BACKGROUND/OBJECTIVES: After Roux-en-Y gastric bypass (RYGB) a subset of patients never obtain excess BMI loss (EBMIL) > 50% and are categorized as having primary weight loss (WL) failure. We hypothesized that postprandial concentrations of glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) would be lower in patients with primary WL failure compared with patients with successfully maintained WL. Furthermore, that inhibition of gut hormone secretions would increase ad libitum food intake less in patients with primary WL failure. SUBJECTS/METHODS: Twenty women with primary WL failure (LowEBMIL < 50%) were individually matched to twenty women with successful WL (HighEBMIL > 60%) on age, preoperative BMI and time from RYGB. On separate days performed in a random order, patient-blinded subcutaneous injections of octreotide or saline (placebo) were followed by a fixed breakfast and an ad libitum lunch with blood sampling for appetite regulating hormones and Visual-Analogue-Scale (VAS)-scoring of hunger/satiety. Furthermore, participants underwent gene variant analysis for GLP-1, PYY and their receptors, indirect calorimetry, dual-energy X-ray absorptiometry (DXA)-scans, 4-days at-home food registration and 14-days step counting. RESULTS: On placebo days, postprandial GLP-1, PYY and cholecystokinin (CCK) concentrations were similar between groups after breakfast. Fasting ghrelin was lower in LowEBMIL, but the postprandial suppression was similar. LowEBMIL had lower satiety VAS-scores and less suppression of hunger VAS-scores. Gene variants did not differ between groups. Octreotide diminished GLP-1, PYY, CCK and ghrelin concentrations in both groups. Octreotide did not affect ad libitum food intake in LowEBMIL (-1% [-13, 12], mean [95%CI]), while food intake increased in HighEBMIL (+23% [2,44]). CONCLUSIONS: Primary WL failure after RYGB was not characterized by impaired secretions of appetite regulating gut hormones. Interestingly, inhibition of gut hormone secretions with octreotide only increased food intake in patients with successful WL post-RYGB. Thus, an impaired central anorectic response to gut hormones may contribute to primary WL failure after RYGB.

Combination of exercise and GLP-1 receptor agonist treatment reduces severity of metabolic syndrome, abdominal obesity, and inflammation: a randomized controlled trial.

BACKGROUND: Identifying and reducing cardiometabolic risks driven by obesity remains a healthcare challenge. The metabolic syndrome is associated with abdominal obesity and inflammation and is predictive of long-term risk of developing type 2 diabetes and cardiovascular disease in otherwise healthy individuals living with obesity. Therefore, we investigated the effects of adherent exercise, a glucagon-like peptide 1 receptor agonist (GLP-1 RA), or the combination on severity of metabolic syndrome, abdominal obesity, and inflammation following weight loss. METHODS: This was a randomized, double-blinded, placebo-controlled trial. During an 8-week low-calorie diet (800 kcal/day), 195 adults with obesity and without diabetes lost 12% in body weight. Participants were then evenly randomized to four arms of one-year treatment with: placebo, moderate-to-vigorous exercise (minimum of 150 min/week of moderate-intensity or 75 min/week of vigorous-intensity aerobic physical activity or an equivalent combination of both), the GLP-1 RA liraglutide 3.0 mg/day, or a combination (exercise + liraglutide). A total of 166 participants completed the trial. We assessed the prespecified secondary outcome metabolic syndrome severity z-score (MetS-Z), abdominal obesity (estimated as android fat via dual-energy X-ray absorptiometry), and inflammation marker high-sensitivity C-reactive protein (hsCRP). Statistical analysis was performed on 130 participants adherent to the study interventions (per-protocol population) using a mixed linear model. RESULTS: The diet-induced weight loss decreased the severity of MetS-Z from 0.57 to 0.06, which was maintained in the placebo and exercise groups after one year. MetS-Z was further decreased by liraglutide (- 0.37, 95% CI - 0.58 to - 0.16, P < 0.001) and the combination treatment (- 0.48, 95% CI - 0.70 to - 0.25, P < 0.001) compared to placebo. Abdominal fat percentage decreased by 2.6, 2.8, and 6.1 percentage points in the exercise, liraglutide, and combination groups compared to placebo, respectively, and hsCRP decreased only in the combination group compared with placebo (by 43%, P = 0.03). CONCLUSION: The combination of adherent exercise and liraglutide treatment reduced metabolic syndrome severity, abdominal obesity, and inflammation and may therefore reduce cardiometabolic risk more than the individual treatments. Trial registration EudraCT number: 2015-005585-32, ClinicalTrials.gov: NCT04122716.

Dietary carbohydrate restriction augments weight loss-induced improvements in glycaemic control and liver fat in individuals with type 2 diabetes: a randomised controlled trial.

AIMS/HYPOTHESIS: Lifestyle modification and weight loss are cornerstones of type 2 diabetes management. However, carbohydrate restriction may have weight-independent beneficial effects on glycaemic control. This has been difficult to demonstrate because low-carbohydrate diets readily decrease body weight. We hypothesised that carbohydrate restriction enhances the beneficial metabolic effects of weight loss in type 2 diabetes. METHODS: This open-label, parallel RCT included adults with type 2 diabetes, HbA1c 48-97 mmol/mol (6.5-11%), BMI >25 kg/m2, eGFR >30 ml min-1 [1.73 m]-2 and glucose-lowering therapy restricted to metformin or dipeptidyl peptidase-4 inhibitors. Participants were randomised by a third party and assigned to 6 weeks of energy restriction (all foods were provided) aiming at ~6% weight loss with either a carbohydrate-reduced high-protein diet (CRHP, percentage of total energy intake [E%]: CH30/P30/F40) or a conventional diabetes diet (CD, E%: CH50/P17/F33). Fasting blood samples, continuous glucose monitoring and magnetic resonance spectroscopy were used to assess glycaemic control, lipid metabolism and intrahepatic fat. Change in HbA1c was the primary outcome; changes in circulating and intrahepatic triacylglycerol were secondary outcomes. Data were collected at Copenhagen University Hospital (Bispebjerg and Herlev). RESULTS: Seventy-two adults (CD 36, CRHP 36, all white, 38 male sex) with type 2 diabetes (mean duration 8 years, mean HbA1c 57 mmol/mol [7.4%]) and mean BMI of 33 kg/m2 were enrolled, of which 67 (CD 33, CRHP 34) completed the study. Body weight decreased by 5.8 kg (5.9%) in both groups after 6 weeks. Compared with the CD diet, the CRHP diet further reduced HbA1c (mean [95% CI] -1.9 [-3.5, -0.3] mmol/mol [-0.18 (-0.32, -0.03)%], p = 0.018) and diurnal mean glucose (mean [95% CI] -0.8 [-1.2, -0.4] mmol/l, p < 0.001), stabilised glucose excursions by reducing glucose CV (mean [95% CI] -4.1 [-5.9, -2.2]%, p < 0.001), and augmented the reductions in fasting triacylglycerol concentration (by mean [95% CI] -18 [-29, -6]%, p < 0.01) and liver fat content (by mean [95% CI] -26 [-45, 0]%, p = 0.051). However, pancreatic fat content was decreased to a lesser extent by the CRHP than the CD diet (mean [95% CI] 33 [7, 65]%, p = 0.010). Fasting glucose, insulin, HOMA2-IR and cholesterol concentrations (total, LDL and HDL) were reduced significantly and similarly by both diets. CONCLUSIONS/INTERPRETATION: Moderate carbohydrate restriction for 6 weeks modestly improved glycaemic control, and decreased circulating and intrahepatic triacylglycerol levels beyond the effects of weight loss itself compared with a CD diet in individuals with type 2 diabetes. Concurrent differences in protein and fat intakes, and the quality of dietary macronutrients, may have contributed to these results and should be explored in future studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT03814694. FUNDING: The study was funded by Arla Foods amba, The Danish Dairy Research Foundation, and Copenhagen University Hospital Bispebjerg Frederiksberg.

Early effects of Roux-en-Y gastric bypass on dietary fatty acid absorption and metabolism in people with obesity and normal glucose tolerance.

INTRODUCTION: Roux-en-Y gastric bypass (RYGB) surgery markedly increases the rate of intestinal nutrient exposure after food intake, accelerates intestinal absorption of dietary glucose and protein, and alters the postprandial gut hormone response. However, our understanding of postprandial fat absorption and metabolism after RYGB is incomplete. METHODS: Stable palmitate tracers were administered intravenously (K-[2,2-2H2]palmitate) and orally with a mixed meal ([U-13C16]palmitate) to study fatty acid absorption and metabolism before and 3 months after RYGB in 10 participants with obesity and normal glucose tolerance. RESULTS: There was a tendency toward reduced fasting plasma nonesterified palmitate concentrations after RYGB, but neither fasting palmitate kinetics nor fasting triacylglycerol (TAG) concentrations changed compared with before surgery. Postprandial TAG concentrations were numerically, but nonsignificantly, reduced 3-4 h after meal intake after compared with before RYGB. However, the postprandial appearance of the oral palmitate tracer in the plasma TAG pool and overflow into the nonesterified palmitate pool were initially faster but overall reduced after RYGB by 50% (median, IQR: [47;64], P = 0.004) and 46% (median, IQR: [33;70], P = 0.041), respectively. The maximal postprandial suppression of plasma nonesterified palmitate concentrations was slightly greater but shorter lasting after RYGB ('time × visit' interaction: P < 0.001), without detectable effects of surgery on the rate of appearance and disappearance of plasma palmitate. CONCLUSION: RYGB resulted in an initially accelerated but overall ~50% reduced 4-h postprandial systemic appearance of dietary palmitate in participants with obesity and normal glucose tolerance. This is likely a result of faster but incomplete intestinal fat absorption combined with enhanced chylomicron-TAG clearance, but it needs further investigation in studies specifically designed to investigate these mechanisms.

Four weeks treatment with the GLP-1 receptor analogue liraglutide lowers liver fat and concomitantly circulating glucagon in individuals with overweight.

We investigated the effect of pharmacologically induced weight loss on markers of glucagon resistance in individuals with overweight during treatment with the glucagon-like peptide-1 receptor agonist liraglutide. We performed an open-label study in 14 men with overweight (age 38 ± 11 years, BMI 32 ± 4 kg/m2) without simultaneously diabetes. Subjects were treated with liraglutide, initiated and titrated with 0.6 mg/day/week to reach the final dose of 3.0 mg/day. Subjects were examined at baseline, during titration (Week 4), after 2 weeks of steady state (Week 6) of final dosing of liraglutide and 3 weeks after discontinuation of liraglutide (follow-up). Study participants lost 3.3 ± 1.9 kg (3%) total body weight during the first 4 weeks of treatment with liraglutide. Simultaneously, liver fat content decreased from 12.4 ± 11.6% to 10.2 ± 11.1%, p = 0.025, whereas fat content in the spleen and subcutaneous tissue was unaltered. Markers of glucagon resistance, including plasma glucagon and the glucagon-alanine-index, also decreased significantly during treatment, but total and individual plasma amino acid concentrations did not. Insulin resistance (HOMA-IR) was unchanged during treatment, whereas insulin clearance increased. Treatment with the GLP-1 receptor analogue liraglutide decreased liver fat content, and simultaneously attenuated glucagon concentrations and the glucagon-alanine index in individuals with overweight without diabetes.

Sperm count is increased by diet-induced weight loss and maintained by exercise or GLP-1 analogue treatment: a randomized controlled trial.

STUDY QUESTION: Does diet-induced weight loss improve semen parameters, and are these possible improvements maintained with sustained weight loss? SUMMARY ANSWER: An 8-week low-calorie diet-induced weight loss was associated with improved sperm concentration and sperm count, which were maintained after 1 year in men who maintained weight loss. WHAT IS KNOWN ALREADY: Obesity is associated with impaired semen quality. Weight loss improves metabolic health in obesity, but there is a lack of knowledge on the acute and long-term effects of weight loss on semen parameters. STUDY DESIGN, SIZE, DURATION: This is a substudy of men with obesity enrolled in a randomized, controlled, double-blinded trial (the S-LITE trial). The trial was conducted between August 2016 and November 2019. A total of 56 men were included in the study and assigned to an initial 8-week low-calorie diet (800 kcal/day) followed by randomization to 52 weeks of either: placebo and habitual activity (placebo), exercise training and placebo (exercise), the Glucagon Like Peptide 1 (GLP-1) analogue liraglutide and habitual activity (liraglutide) or liraglutide in combination with exercise training (combination). PARTICIPANTS/MATERIALS, SETTING, METHODS: Inclusion criteria were men who delivered semen samples, 18 to 65 years of age, and a body mass index between 32 and 43 kg/m2, but otherwise healthy. The study was carried out at Hvidovre Hospital and at the University of Copenhagen, and the participants were from the Greater Copenhagen Area. We assessed semen parameters and anthropometrics and collected blood samples before (T0), after the 8-week low-calorie dietary intervention (T1), and after 52 weeks (T2). MAIN RESULTS AND THE ROLE OF CHANCE: The men lost on average 16.5 kg (95% CI: 15.2-17.8) body weight during the low-calorie diet, which increased sperm concentration 1.49-fold (95% CI: 1.18-1.88, P < 0.01) and sperm count 1.41-fold (95% CI: 1.07-1.87, P < 0.01). These improvements were maintained for 52 weeks in men who maintained the weight loss, but not in men who regained weight. Semen volume, sperm motility and motile sperm count did not change. LIMITATIONS, REASONS FOR CAUTION: The S-LITE trial was a randomized controlled trial of weight loss maintenance. Analysis of semen was preregistered to explore the effects of weight loss and weight loss maintenance on semen parameters, but definite inferences cannot be made. WIDER IMPLICATIONS OF THE FINDINGS: This study shows that sperm concentration and sperm count were improved after a diet-induced weight loss in men with obesity. Our findings indicate that either or both liraglutide and exercise as weight maintenance strategies may be used to maintain the improvements in sperm concentration and count. STUDY FUNDING/COMPETING INTEREST(S): This work is supported by an excellence grant from the Novo Nordisk Foundation (NNF16OC0019968), a Challenge Programme Grant from the Novo Nordisk Foundation (NNF18OC0033754) and a grant from Helsefonden. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent research centre at the University of Copenhagen, partially funded by an unrestricted donation from the Novo Nordisk Foundation (NNF18CC0034900). Saxenda (liraglutide) and placebo pens were provided by Novo Nordisk. Cambridge Weight Plan diet products for the 8-week low-calorie diet were provided by Cambridge Weight Plan. E.A.: shareholder, employee of ExSeed Health Ltd. Grant Recipient from ExSeed Health Ltd and listed on Patents planned, issued or pending with ExSeed Health Ltd; J.J.H.: consultant for Eli Lilly A/S and Novo Nordisk A/S. Lecture fees for Novo Nordisk A/S. Listed on Patents planned, issued or pending with the University of Copenhagen, Advocacy group for Antag Therapeutics and Bainan Biotech; S.M.: lecture fees for Novo Nordisk A/S. Recipient of Support for attending meetings from Novo Nordisk A/S. Advisory boards of Novo Nordisk A/S; Sanofi Aventis and Merck Sharp & Dohme. S.S.T.: research grant recipient Novo Nordisk. The remaining authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: The trial was approved by the Ethical Committee of the Capital Region of Denmark (H-16027082) and the Danish Medicines Agency (EudraCT Number: 2015-005585-32). ClinicalTrials.gov identifier (NCT number): NCT04122716. TRIAL REGISTRATION DATE: 11 May 2016. DATE OF FIRST PATIENT'S ENROLMENT: August 2016.

GIP and GLP-2 together improve bone turnover in humans supporting GIPR-GLP-2R co-agonists as future osteoporosis treatment.

The intestinal hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are key regulators of postprandial bone turnover in humans. We hypothesized that GIP and GLP-2 co-administration would provide stronger effect on bone turnover than administration of the hormones separately, and tested this using subcutaneous injections of GIP and GLP-2 alone or in combination in humans. Guided by these findings, we designed series of GIPR-GLP-2R co-agonists as template for new osteoporosis treatment. The clinical experiment was a randomized cross-over design including 10 healthy men administered subcutaneous injections of GIP and GLP-2 alone or in combination. The GIPR-GLP-2R co-agonists were characterized in terms of binding and activation profiles on human and rodent GIP and GLP-2 receptors, and their pharmacokinetic (PK) profiles were improved by dipeptidyl peptidase-4 protection and site-directed lipidation. Co-administration of GIP and GLP-2 in humans resulted in an additive reduction in bone resorption superior to each hormone individually. The GIPR-GLP-2R co-agonists, designed by combining regions of importance for cognate receptor activation, obtained similar efficacies as the two native hormones and nanomolar potencies on both human receptors. The PK-improved co-agonists maintained receptor activity along with their prolonged half-lives. Finally, we found that the GIPR-GLP-2R co-agonists optimized toward the human receptors for bone remodeling are not feasible for use in rodent models. The successful development of potent and efficacious GIPR-GLP-2R co-agonists, combined with the improved effect on bone metabolism in humans by co-administration, support these co-agonists as a future osteoporosis treatment.

Liraglutide changes body composition and lowers added sugar intake in overweight persons with insulin pump-treated type 1 diabetes.

AIMS: To present secondary outcome analyses of liraglutide treatment in overweight adults with insulin pump-treated type 1 diabetes (T1D), focusing on changes in body composition and dimensions, and to evaluate changes in food intake to identify potential dietary drivers of liraglutide-associated weight loss. MATERIALS AND METHODS: A 26-week randomized placebo-controlled study was conducted to investigate the efficacy and safety of liraglutide 1.8 mg daily in 44 overweight adults with insulin pump-treated T1D and glucose levels above target, and demonstrated significant glycated haemoglobin (HbA1c)- and body weight-reducing effects. For secondary outcome analysis, dual X-ray absorptiometry scans were completed at Weeks 0 and 26, and questionnaire-based food frequency recordings were obtained at Weeks 0, 13 and 26 to characterize liraglutide-induced changes in body composition and food intake. RESULTS: Total fat and lean body mass decreased in liraglutide-treated participants (fat mass -4.6 kg [95% confidence interval {CI} -5.7; -3.5], P < 0.001; lean mass -2.5 kg [95% CI -3.2;-1.7], P < 0.001), but remained stable in placebo-treated participants (fat mass -0.3 kg [95% CI -1.3;0.8], P = 0.604; lean mass 0.0 kg [95% CI -0.7;0.7]; P = 0.965 [between-group P values <0.001]). Participants reduced their energy intake numerically more in the liraglutide arm (-1.1 MJ [95% CI -2.0;-0.02], P = 0.02) than in the placebo arm (-0.9 MJ [95% CI -2.0;0.1], P = 0.22), but the between-group difference was statistically insignificant (P = 0.42). However, energy derived from added sugars decreased by 27% in the liraglutide arm compared with an increase of 14% in the placebo arm (P = 0.004). CONCLUSIONS: Liraglutide lowered fat and lean body mass compared with placebo. Further, liraglutide reduced intake of added sugars. However, no significant difference in total daily energy intake was detected between liraglutide- and placebo-treated participants.

Acute effects on glucose tolerance by neprilysin inhibition in patients with type 2 diabetes.

AIMS: Sacubitril/valsartan is a neprilysin-inhibitor/angiotensin II receptor blocker used for the treatment of heart failure. Recently, a post-hoc analysis of a 3-year randomized controlled trial showed improved glycaemic control with sacubitril/valsartan in patients with heart failure and type 2 diabetes. We previously reported that sacubitril/valsartan combined with a dipeptidyl peptidase-4 inhibitor increases active glucagon-like peptide-1 (GLP-1) in healthy individuals. We now hypothesized that administration of sacubitril/valsartan with or without a dipeptidyl peptidase-4 inhibitor would lower postprandial glucose concentrations (primary outcome) in patients with type 2 diabetes via increased active GLP-1. METHODS: We performed a crossover trial in 12 patients with obesity and type 2 diabetes. A mixed meal was ingested following five respective interventions: (a) a single dose of sacubitril/valsartan; (b) sitagliptin; (c) sacubitril/valsartan + sitagliptin; (d) control (no treatment); and (e) valsartan alone. Glucose, gut and pancreatic hormone responses were measured. RESULTS: Postprandial plasma glucose increased by 57% (incremental area under the curve 0-240 min) (p = .0003) and increased peak plasma glucose by 1.7 mM (95% CI: 0.6-2.9) (p = .003) after sacubitril/valsartan compared with control, whereas postprandial glucose levels did not change significantly after sacubitril/valsartan + sitagliptin. Glucagon, GLP-1 and C-peptide concentrations increased after sacubitril/valsartan, but insulin and glucose-dependent insulinotropic polypeptide did not change. CONCLUSIONS: The glucose-lowering effects of long-term sacubitril/valsartan treatment reported in patients with heart failure and type 2 diabetes may not depend on changes in entero-pancreatic hormones. Neprilysin inhibition results in hyperglucagonaemia and this may explain the worsen glucose tolerance observed in this study. CLINICALTRIALS: gov (NCT03893526).

On measurements of glucagon secretion in healthy, obese, and Roux-en-Y gastric bypass operated individuals using sandwich ELISA.

Glucagon is a key regulator of metabolism and is used in the diagnostic of neuroendocrine tumors. Accurate measurement of glucagon requires both extreme sensitivity and specificity since several peptides are derived from the same proglucagon precursor encoding part of the glucagon sequence and given that glucagon circulates in picomolar concentrations. A sandwich ELISA was recently developed and extensively evaluated; however, this method may not be accurate when measuring glucagon in patients with an enhanced production of proglucagon-derived peptides as seen after Roux-en-Y gastric bypass (RYGB). To overcome this, a modified version of the ELISA was developed. In this study, we evaluate an unmodified and a modified version of the ELISA in healthy individuals, individuals with obesity, and finally in two cohorts of patients following RYGB surgery using different nutrient stimuli to assess glucagon dynamics. Finally, in vitro spike-in recoveries using native glucagon and proglucagon-derived peptides were performed in buffer and in plasma. Our data support that both versions of the ELISA accurately capture endogenous and exogenous glucagon in healthy individuals and in individuals with obesity. However, the unmodified version of the assay may overestimate glucagon levels in patients following RYGB in line with minimal but consistent cross-reactivity to oxyntomodulin and glicentin that both are 50-fold increased after RYGB. Importantly, we did not find any changes between the two protocols at fasted conditions and therefore diagnostics of glucagonomas is not affected by the choice of assay procedure nor the surgical history of the patient (RYGB).

Impact of prolonged fasting on insulin secretion, insulin action, and hepatic versus whole body insulin secretion disposition indices in healthy young males.

The extent to which reduced insulin secretion during prolonged fasting reflects failure to compensate for whole body insulin resistance or a normal adjustment to potentially increased hepatic insulin action is unknown. We examined the effects of 36- versus 12-h fasting on insulin secretion and whole body versus hepatic insulin action in 13 healthy young males. Hepatic glucose production and insulin action were studied using stable isotopes, whereas whole body insulin action and insulin secretion were studied using an intravenous glucose tolerance test (IVGTT) and minimal modeling. Insulin, glucose, and lipid profiles were subsequently measured during a refeeding meal test. Prolonged fasting caused a minor reduction of first-phase insulin secretion in a context of improved hepatic insulin action, contrasting an increase in whole body insulin resistance. Accordingly, prolonged fasting was associated with opposite-directed effects on hepatic versus whole body insulin secretion disposition indices. Thirty-six-hour fasting compared with 12-h fasting was associated with increased serum insulin levels during the refeeding meal test. In conclusion, reduced insulin secretion during prolonged fasting may represent a healthy response to improved hepatic insulin action. Use of insulin secretion disposition indices without taking organ-specific insulin action into account may lead to erroneous conclusions.NEW & NOTEWORTHY Thirty-six-hour prolonged, compared with 12-h overnight fasting, is associated with slightly reduced first-phase insulin secretion in the face of opposite-directed changes in hepatic versus whole body insulin action in healthy young males. The paradoxical finding of increased hepatic versus decreased whole body insulin secretion disposition indices during prolonged fasting challenges the physiological understanding and validity of insulin secretion disposition indices not taking organ-specific insulin action into account.

Plasma GDF15 levels are similar between subjects after bariatric surgery and matched controls and are unaffected by meals.

Growth differentiating factor 15 (GDF15) is expressed in the intestine and is one of the most recently identified satiety peptides. The mechanisms controlling its secretion are unclear. The present study investigated whether plasma GDF15 concentrations are meal-related and if potential responses depend on macronutrient type or are affected by previous bariatric surgery. The study included 1) volunteers ingesting rapidly vs. slowly digested carbohydrates (sucrose vs. isomaltose; n = 10), 2) volunteers who had undergone Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery and unoperated matched controls ingesting a liquid mixed meal (n = 9-10 in each group), and 3) individuals with previous RYGB compared with unoperated controls ingesting isocaloric glucose, fat, or protein (n = 6 in each group). Plasma was collected after an overnight fast and up to 6 h after ingestion (≥12 time points). In cohort 1, fasting GDF15 concentrations were ∼480 pg/mL. Concentrations after sucrose or isomaltose intake did not differ from baseline (P = 0.26 to P > 0.99) and total area under the curves (tAUCs were similar between groups (P = 0.77). In cohort 2, fasting GDF15 concentrations were as follows (pg/mL): RYGB = 540 ± 41.4, SG = 477 ± 36.4, and controls = 590 ± 41.8, with no between-group differences (P = 0.73). Concentrations did not increase at any postprandial time point (over all time factor: P = 0.10) and tAUCs were similar between groups (P = 0.73). In cohort 3, fasting plasma GDF15 was similar among the groups (P > 0.99) and neither glucose, fat, nor protein intake consistently increased the concentrations. In conclusion, we find that plasma GDF15 was not stimulated by meal intake and that fasting concentrations did not differ between RYGB-, SG-, and body mass index (BMI)-matched controls when investigated during the weight stable phase after RYGB and SG.NEW & NOTEWORTHY Our combined data show that GDF15 does not increase in response to a liquid meal. Moreover, we show for the first time that ingestion of sucrose, isomaltose, glucose, fat, or protein also does not increase plasma GDF15 concentrations, questioning the role of GDF15 in regulation of food source preference. Finally, we find that neither fasting nor postprandial plasma GDF15 concentrations are increased in individuals with previous bariatric surgery compared with unoperated body mass index (BMI)-matched controls.