Elucidating the glucose-lowering effect of the bile acid sequestrant sevelamer.

AIM: Bile acid sequestrants are cholesterol-lowering drugs, which also improve glycaemic control in people with type 2 diabetes. The mechanism behind the glucose-lowering effect is unknown but has been proposed to be mediated by increased glucagon-like peptide-1 (GLP-1) secretion. Here, we investigated the glucose-lowering effects of sevelamer including any contribution from GLP-1 in people with type 2 diabetes. MATERIALS AND METHODS: In a randomized, double-blind, placebo-controlled, crossover study, 15 people with type 2 diabetes on metformin monotherapy underwent two 17-day treatment periods with the bile acid sequestrant sevelamer and placebo, respectively, in a randomized order and with an interposed wash-out period of minimum 6 weeks. On days 15 and 17 of each treatment period, participants underwent experimental days with 4-h liquid meal tests and application of concomitant infusion of exendin(9-39)NH2 or saline. RESULTS: Compared with placebo, sevelamer improved insulin sensitivity (assessed by homeostatic model assessment of insulin resistance) and beta-cell sensitivity to glucose and lowered fasting and postprandial plasma glucose concentrations. In both treatment periods, exendin(9-39)NH2 increased postprandial glucose excursions compared with saline but without absolute or relative difference between the two treatment periods. In contrast, exendin(9-39)NH2 abolished the sevelamer-induced improvement in beta-cell glucose sensitivity. CONCLUSIONS: The bile acid sequestrant sevelamer improved insulin sensitivity and beta-cell sensitivity to glucose, but using the GLP-1 receptor antagonist exendin(9-39)NH2 we were not able to detect a GLP-1-mediated glucose-lowering effect of sevelamer in individuals with type 2 diabetes. Nevertheless, the sevelamer-induced improvement of beta-cell sensitivity to glucose was shown to be GLP-1-dependent.

Single-dose Tadalafil Reduces Opening Urethral Pressure: A Randomized, Double-blind, Placebo-controlled, Crossover Trial in Healthy Women.

INTRODUCTION AND HYPOTHESIS: Phosphodiesterase enzymes are widely distributed in female urogenital tissues. Yet, the understanding of their physiological roles and the impact of phosphodiesterase inhibitors on lower urinary tract symptoms in women remains limited. Current hypotheses are conflicting: one suggests that vasodilation might expand the periurethral vascular plexus, leading to increased urethral pressure, whereas the other proposes a relaxation of urethral musculature, resulting in decreased pressure. To further clarify this, we investigated the effect of tadalafil on the opening urethral pressure and voiding function in healthy women. METHODS: We conducted a randomized, double-blind, placebo-controlled crossover trial involving 24 healthy women. Participants were randomly assigned to receive a single dose of tadalafil (40 mg) or placebo during their initial visit and then switched to the alternative treatment during their second visit. Opening urethral pressure was measured with urethral pressure reflectometry during both resting and squeezing conditions of the pelvic floor. Subsequently, voiding parameters were recorded. RESULTS: Compared with placebo, a single dose of tadalafil significantly reduced opening urethral pressure during both resting (-6.8 cmH20; 95% confidence interval [CI], -11.8 to -1.9; p = 0.009) and squeezing conditions (-8.8 cmH20; 95% CI, -14.6 to -3.1; p = 0.005). Voiding parameters did not show significant differences (average flow rate: -0.8 ml/s [95% CI, -2.0 to 0.4; p = 0.2]; maximum flow rate: -1.7 ml/s [95% CI, -4.8 to 1.5; p = 0.3]). CONCLUSIONS: A single dose of 40 mg tadalafil moderately reduced urethral pressure in healthy women, without affecting voiding parameters. The clinical implications of this are yet to be determined.

Liraglutide changes postprandial responses of gut hormones involved in the regulation of gallbladder motility.

AIM: Liraglutide treatment is associated with gallbladder-related disorders and has been shown to delay postprandial gallbladder refilling. The gut hormones cholecystokinin (CCK), fibroblast growth factor 19 (FGF19) and glucagon-like peptide 2 (GLP-2), are known to regulate gallbladder motility and may be implicated in gallbladder-related disorders associated with liraglutide treatment. MATERIALS AND METHODS: In a double-blind, 12-week trial, 52 participants [50% male, age 47.6 ± 10.0 years, body mass index 32.6 ± 3.4 kg/m2 (mean ± standard deviation)] with obesity were randomized 1:1 to once-daily subcutaneous liraglutide (escalated from 0.6 mg to 3.0 mg once-daily) or placebo. During liquid meal tests performed at baseline, after the first dose and following 12 weeks of treatment, we evaluated postprandial gallbladder dynamics and plasma responses of CCK, FGF19 and GLP-2. RESULTS: Liraglutide reduced postprandial FGF19 after the first dose [area under the curve (AUC)0-240 min 24.8 vs. 48.0 min × ng/ml, treatment ratio (TR) (95% confidence interval) 0.52 (0.39; 0.69)] and following 12 weeks of treatment [AUC0-240 min 33.7 vs. 48.5 ng/ml × min, TR 0.69 (0.52; 0.93)]. Liraglutide also reduced postprandial GLP-2 responses (AUC0-240 min 3650 vs. 4894 min × pmol/L, TR 0.75 (0.62; 0.90)] following the first dose as well as after 12 weeks [AUC0-240 min 3760 vs. 4882 min × pmol/L, TR 0.77 (0.60; 0.99)]. Liraglutide increased postprandial responses of CCK after the first dose [AUC0-240 min 762 vs. 670 min × pmol/L; TR 1.14 (0.97; 1.33)] and following 12 weeks of treatment [AUC0-240 min 873 vs. 628 min × pmol/L; TR 1.39 (1.12; 1.73)]. CONCLUSION: Compared with placebo, treatment with liraglutide decreased postprandial FGF19 and GLP-2 concentrations and increased postprandial CCK concentrations, which may explain the delayed postprandial gallbladder refilling observed in individuals with obesity treated with liraglutide.

Effect of single doses of citalopram and reboxetine on urethral pressure: A randomized, double-blind, placebo- and active-controlled three-period crossover study in healthy women.

AIMS: Urethral closure function is essential for urinary continence in women and decreased urethral pressure is associated with stress urinary incontinence (SUI). For decades, the effects of serotonergic drugs on central neural control of urethral closure have been investigated and discussed. Epidemiological studies suggest that the use of selective serotonin reuptake inhibitors (SSRIs), such as citalopram, is associated with SUI. However, the literature findings are conflicting. This study aimed to evaluate citalopram's effect on opening urethral pressure (OUP) in healthy women. METHODS: We conducted a randomized, double-blind, placebo- and active-controlled crossover study in 24 healthy women. On three study days, which were separated by 8 days of washout, the subjects received single doses of either 40 mg citalopram (and placeboreboxetine ), 8 mg reboxetine (and placebocitalopram ), or two placebos. Study drugs were administered at a 1-h interval due to a difference in estimated time to peak plasma concentration (tmax ). We measured OUP with urethral pressure reflectometry under both resting and squeezing conditions of the pelvic floor at estimated tmax for both study drugs (one timepoint). RESULTS: Compared to placebo, citalopram increased OUP by 6.6 cmH2 0 (95% confidence interval [CI] 0.04-13.1, p = 0.048) in resting condition. In squeezing condition, OUP increased by 7.1 cmH2 0 (95% CI: 1.3-12.9, p = 0.01). Reboxetine increased OUP by 30.0 cmH2 0 in resting condition compared to placebo (95% CI: 23.5-36.5, p < 0.001), and 27.0 cmH2 0 (95% CI: 21.2-32.8, p < 0.001) in squeezing condition. CONCLUSION: Citalopram increased OUP slightly compared to placebo suggesting that SSRI treatment does not induce or aggravate SUI.

Effects of liraglutide on gallbladder emptying: A randomized, placebo-controlled trial in adults with overweight or obesity.

AIMS: Treatment with liraglutide 3.0 mg has been associated with gallbladder-related adverse events. To conduct a single-centre, double-blind, 12-week trial comparing the effect of 0.6 mg liraglutide and steady-state liraglutide 3.0 mg with placebo on gallbladder emptying in adults with body mass index (BMI) ≥27 kg/m2 and without diabetes. METHODS: Participants were randomized 1:1 to once-daily subcutaneous liraglutide (n = 26) or placebo (n = 26), starting at 0.6 mg with 0.6-mg weekly increments to 3.0 mg, with nutritional and physical activity counselling. A 600-kcal (23.7 g fat) liquid meal test was performed at baseline, after the first dose and after 12 weeks. The primary endpoint was the 12-week maximum postprandial gallbladder ejection fraction (GBEFmax ), measured over 240 minutes after starting the meal. RESULTS: Baseline characteristics were similar between groups (mean ± SD overall age 47.6 ± 10.0 years, BMI 32.6 ±3.4 kg/m2 , 50% women). Mean 12-week GBEFmax (treatment difference -3.7%, 95% confidence interval [CI] -13.1, 5.7) and area under the GBEF curve in the first 60 minutes (-390% × min, 95% CI -919, 140) did not differ for liraglutide 3.0 mg (n = 23) vs placebo (n = 24). The median (range) time to GBEFmax was 151 (11-240) minutes with liraglutide 3.0 mg and 77 (22-212) minutes with placebo. Similar findings were noted after the first 0.6-mg liraglutide dose. Gastrointestinal disorders, notably nausea and constipation, were the most frequently reported adverse events. CONCLUSIONS: Treatment with liraglutide did not affect the GBEFmax but appeared to prolong the time to GBEFmax .

Glucose-lowering effects and mechanisms of the bile acid-sequestering resin sevelamer.

AIMS: Sevelamer, a non-absorbable amine-based resin used for treatment of hyperphosphataemia, has been demonstrated to have a marked bile acid-binding potential alongside beneficial effects on lipid and glucose metabolism. The aim of this study was to investigate the glucose-lowering effect and mechanism(s) of sevelamer in patients with type 2 diabetes. MATERIALS AND METHODS: In this double-blinded randomized controlled trial, we randomized 30 patients with type 2 diabetes to sevelamer (n = 20) or placebo (n = 10). Participants were subjected to standardized 4-hour liquid meal tests at baseline and after 7 days of treatment. The main outcome measure was plasma glucagon-like peptide-1 excursions as measured by area under the curve. In addition, blood was sampled for measurements of glucose, lipids, glucose-dependent insulinotropic polypeptide, C-peptide, glucagon, fibroblast growth factor-19, cholecystokinin and bile acids. Assessments of gastric emptying, resting energy expenditure and gut microbiota composition were performed. RESULTS: Sevelamer elicited a significant placebo-corrected reduction in plasma glucose with concomitant reduced fibroblast growth factor-19 concentrations, increased de novo synthesis of bile acids, a shift towards a more hydrophilic bile acid pool and increased lipogenesis. No glucagon-like peptide-1-mediated effects on insulin, glucagon or gastric emptying were evident, which points to a limited contribution of this incretin hormone to the glucose-lowering effect of sevelamer. Furthermore, no sevelamer-mediated effects on gut microbiota composition or resting energy expenditure were observed. CONCLUSIONS: Sevelamer reduced plasma glucose concentrations in patients with type 2 diabetes by mechanisms that seemed to involve decreased intestinal and hepatic bile acid-mediated farnesoid X receptor activation.

Evidence connecting old, new and neglected glucose-lowering drugs to bile acid-induced GLP-1 secretion: A review.

Bile acids are amphipathic water-soluble steroid-based molecules best known for their important lipid-solubilizing role in the assimilation of fat. Recently, bile acids have emerged as metabolic integrators with glucose-lowering potential. Among a variety of gluco-metabolic effects, bile acids have been demonstrated to modulate the secretion of the gut-derived incretin hormone glucagon-like peptide-1 (GLP-1), possibly via the transmembrane receptor Takeda G-protein-coupled receptor 5 and the nuclear farnesoid X receptor, in intestinal L cells. The present article critically reviews current evidence connecting established glucose-lowering drugs to bile acid-induced GLP-1 secretion, and discusses whether bile acid-induced GLP-1 secretion may constitute a new basis for understanding how metformin, inhibitors of the apical sodium-dependent bile acids transporter, and bile acid sequestrants - old, new and neglected glucose-lowering drugs - improve glucose metabolism.

Dipeptidyl-peptidase (DPP)-4 inhibitors and glucagon-like peptide (GLP)-1 analogues for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk for the development of type 2 diabetes mellitus.

BACKGROUND: The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether dipeptidyl-peptidase (DPP)-4 inhibitors or glucagon-like peptide (GLP)-1 analogues are able to prevent or delay T2DM and its associated complications in people at risk for the development of T2DM is unknown. OBJECTIVES: To assess the effects of DPP-4 inhibitors and GLP-1 analogues on the prevention or delay of T2DM and its associated complications in people with impaired glucose tolerance, impaired fasting blood glucose, moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; MEDLINE; PubMed; Embase; ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform; and the reference lists of systematic reviews, articles and health technology assessment reports. We asked investigators of the included trials for information about additional trials. The date of the last search of all databases was January 2017. SELECTION CRITERIA: We included randomised controlled trials (RCTs) with a duration of 12 weeks or more comparing DPP-4 inhibitors and GLP-1 analogues with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with impaired fasting glucose, impaired glucose tolerance, moderately elevated HbA1c or combinations of these. DATA COLLECTION AND ANALYSIS: Two review authors read all abstracts and full-text articles and records, assessed quality and extracted outcome data independently. One review author extracted data which were checked by a second review author. We resolved discrepancies by consensus or the involvement of a third review author. For meta-analyses, we planned to use a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall quality of the evidence using the GRADE instrument. MAIN RESULTS: We included seven completed RCTs; about 98 participants were randomised to a DPP-4 inhibitor as monotherapy and 1620 participants were randomised to a GLP-1 analogue as monotherapy. Two trials investigated a DPP-4 inhibitor and five trials investigated a GLP-1 analogue. A total of 924 participants with data on allocation to control groups were randomised to a comparator group; 889 participants were randomised to placebo and 33 participants to metformin monotherapy. One RCT of liraglutide contributed 85% of all participants. The duration of the intervention varied from 12 weeks to 160 weeks. We judged none of the included trials at low risk of bias for all 'Risk of bias' domains and did not perform meta-analyses because there were not enough trials.One trial comparing the DPP-4 inhibitor vildagliptin with placebo reported no deaths (very low-quality evidence). The incidence of T2DM by means of WHO diagnostic criteria in this trial was 3/90 participants randomised to vildagliptin versus 1/89 participants randomised to placebo (very low-quality evidence). Also, 1/90 participants on vildagliptin versus 2/89 participants on placebo experienced a serious adverse event (very low-quality evidence). One out of 90 participants experienced congestive heart failure in the vildagliptin group versus none in the placebo group (very low-quality evidence). There were no data on non-fatal myocardial infarction, stroke, health-related quality of life or socioeconomic effects reported.All-cause and cardiovascular mortality following treatment with GLP-1 analogues were rarely reported; one trial of exenatide reported that no participant died. Another trial of liraglutide 3.0 mg showed that 2/1501 in the liraglutide group versus 2/747 in the placebo group died after 160 weeks of treatment (very low-quality evidence).The incidence of T2DM following treatment with liraglutide 3.0 mg compared to placebo after 160 weeks was 26/1472 (1.8%) participants randomised to liraglutide versus 46/738 (6.2%) participants randomised to placebo (very low-quality evidence). The trial established the risk for (diagnosis of) T2DM as HbA1c 5.7% to 6.4% (6.5% or greater), fasting plasma glucose 5.6 mmol/L or greater to 6.9 mmol/L or less (7.0 mmol/L or greater) or two-hour post-load plasma glucose 7.8 mmol/L or greater to 11.0 mmol/L (11.1 mmol/L). Altogether, 70/1472 (66%) participants regressed from intermediate hyperglycaemia to normoglycaemia compared with 268/738 (36%) participants in the placebo group. The incidence of T2DM after the 12-week off-treatment extension period (i.e. after 172 weeks) showed that five additional participants were diagnosed T2DM in the liraglutide group, compared with one participant in the placebo group. After 12-week treatment cessation, 740/1472 (50%) participants in the liraglutide group compared with 263/738 (36%) participants in the placebo group had normoglycaemia.One trial used exenatide and 2/17 participants randomised to exenatide versus 1/16 participants randomised to placebo developed T2DM (very low-quality evidence). This trial did not provide a definition of T2DM. One trial reported serious adverse events in 230/1524 (15.1%) participants in the liraglutide 3.0 mg arm versus 96/755 (12.7%) participants in the placebo arm (very low quality evidence). There were no serious adverse events in the trial using exenatide. Non-fatal myocardial infarction was reported in 1/1524 participants in the liraglutide arm and in 0/55 participants in the placebo arm at 172 weeks (very low-quality evidence). One trial reported congestive heart failure in 1/1524 participants in the liraglutide arm and in 1/755 participants in the placebo arm (very low-quality evidence). Participants receiving liraglutide compared with placebo had a small mean improvement in the physical component of the 36-item Short Form scale showing a difference of 0.87 points (95% CI 0.17 to 1.58; P = 0.02; 1 trial; 1791 participants; very low-quality evidence). No trial evaluating GLP-1-analogues reported data on stroke, microvascular complications or socioeconomic effects. AUTHORS' CONCLUSIONS: There is no firm evidence that DPP-4 inhibitors or GLP-1 analogues compared mainly with placebo substantially influence the risk of T2DM and especially its associated complications in people at increased risk for the development of T2DM. Most trials did not investigate patient-important outcomes.

Involvement of glucagon-like peptide-1 in the glucose-lowering effect of metformin.

Metformin is an oral antihyperglycaemic drug used in the first-line treatment of type 2 diabetes. Metformin's classic and most well-known blood glucose-lowering mechanisms include reduction of hepatic gluconeogenesis and increased peripheral insulin sensitivity. Interestingly, intravenously administered metformin is ineffective and recently, metformin was shown to increase plasma concentrations of the glucose-lowering gut incretin hormone glucagon-like peptide-1 (GLP-1), which may contribute to metformin's glucose-lowering effect in patients with type 2 diabetes. The mechanisms behind metformin-induced increments in GLP-1 levels remain unknown, but it has been hypothesized that metformin stimulates GLP-1 secretion directly and/or indirectly and that metformin prolongs the half-life of GLP-1. Also, it has been suggested that metformin may potentiate the glucose-lowering effects of GLP-1 by increasing target tissue sensitivity to GLP-1. The present article critically reviews the possible mechanisms by which metformin may affect GLP-1 levels and sensitivity and discusses whether such alterations may constitute important and clinically relevant glucose-lowering actions of metformin.

Bile acid sequestrants: glucose-lowering mechanisms and efficacy in type 2 diabetes.

Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid and glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption of the enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose-lowering effect in patients with type 2 diabetes remain unclear. This article offers a review of the mechanisms behind the glucose-lowering effect of BASs, and the efficacy of BASs in the treatment of type 2 diabetes.

Colesevelam has no acute effect on postprandial GLP-1 levels but abolishes gallbladder refilling.

OBJECTIVE: Colesevelam, a bile acid sequestrant approved for the treatment of hypercholesterolaemia, improves glycaemic control in type 2 diabetes. We hypothesised that single-dose colesevelam increases postprandial GLP-1 secretion, thus, reducing postprandial glucose excursions in individuals with type 2 diabetes. Further, we explored the effects of single-dose colesevelam on ultrasonography-assessed postprandial gallbladder motility, paracetamol absorption (proxy for gastric emptying), and circulating factors known to affect gallbladder motility. METHODS: In a randomised, double-blind, placebo-controlled crossover study, 12 individuals with type 2 diabetes (mean ± SD: age 61 ± 8.8 years; body mass index 29.8 ± 3.0 kg/m2) were subjected to 4 mixed meal tests on separate days; 2 with orally administered colesevelam (3.75 g) and 2 with placebo, with intravenous infusion of the GLP-1 receptor antagonist exendin(9-39)NH2 or saline. RESULTS: Single-dose colesevelam had no effect on postprandial concentrations of glucose (P = .786), C-peptide (P = .440), or GLP-1 (P = .729), and exendin(9-39)NH2 administration revealed no GLP-1-mediated effects of colesevelam. Colesevelam did not affect gallbladder emptying but abolished gallbladder refilling (P = .001), increased postprandial cholecystokinin (CCK) secretion (P = .010), and decreased postprandial serum concentrations of fibroblast growth factor 19 (FGF19) (P = .035) and bile acids (P = .043). CONCLUSION: Single-dose colesevelam had no effect on postprandial GLP-1 responses or glucose tolerance but disrupted postprandial gallbladder refilling by increasing CCK secretion and reducing circulating concentrations of FGF19 and bile acids. These findings leave the antidiabetic actions of colesevelam unresolved but provide mechanistic insights into its effect on gallbladder motility.

The bile-gut axis and metabolic consequences of cholecystectomy.

Cholelithiasis and cholecystitis affect individuals of all ages and are often treated by surgical removal of the gallbladder (cholecystectomy), which is considered a safe, low-risk procedure. Nevertheless, recent findings show that bile and its regulated storage and excretion may have important metabolic effects and that cholecystectomy is associated with several metabolic diseases postoperatively. Bile acids have long been known as emulsifiers essential to the assimilation of lipids and absorption of lipid-soluble vitamins, but more recently, they have also been reported to act as metabolic signaling agents. The nuclear receptor, farnesoid X receptor (FXR), and the G protein-coupled membrane receptor, Takeda G protein-coupled receptor 5 (TGR5), are specific to bile acids. Through activation of these receptors, bile acids control numerous metabolic functions. Cholecystectomy affects the storage and excretion of bile acids, which in turn may influence the activation of FXR and TGR5 and their effects on metabolism including processes leading to metabolic conditions such as metabolic dysfunction-associated steatotic liver disease and metabolic syndrome. Here, with the aim of elucidating mechanisms behind cholecystectomy-associated dysmetabolism, we review studies potentially linking cholecystectomy and bile acid-mediated metabolic effects and discuss possible pathophysiological mechanisms behind cholecystectomy-associated dysmetabolism.

Expression of bile acid receptors and transporters along the intestine of patients with type 2 diabetes and controls.

CONTEXT: The enterohepatic circulation of bile acids depends on intestinal absorption by bile acid transporters and activation of bile acid receptors, which stimulates secretion of hormones regulating glucose and lipid metabolism and appetite. Distribution of bile acid transporters and receptors in the human gut and their potential involvement in type 2 diabetes (T2D) pathophysiology remain unknown. OBJECTIVE: We explored the expression of genes involved in bile acid metabolism throughout the intestines of patients with T2D and matched healthy controls. METHODS: Intestinal mucosa biopsies sampled along the intestinal tract in 12 individuals with T2D and 12 healthy controls were subjected to mRNA sequencing. We report expression profiles of apical sodium-dependent bile acid transporter (ASBT), organic solute transporter (OST) α/ß, farnesoid X receptor (FXR), Takeda G receptor 5 (TGR5), fibroblast growth factor 19 (FGF19) and FGF receptor 4 (FGFR4). RESULTS: Expression of ASBT and OSTα/ß was evident in the duodenum of both groups with increasing levels through the small intestine, and no (ASBT) or decreasing levels (OSTα/ß) through the large intestine. The FXR expression pattern followed that of OSTα/ß whereas FGFR4 were evenly expressed through the intestines. Negligible levels of TGR5 and FGF19 were evident. Patients with T2D exhibited lower levels of FGF19, FXR, ASBT and OSTα/ß mRNAs compared with healthy controls, although the differences were not statistically significant after adjusting for multiple testing. CONCLUSIONS: We demonstrate distinct expression patterns of bile acid transporters and receptors through the intestinal tract with signs of reduced ASBT, OSTα/ß, FXR and FGF19 mRNAs in T2D.

Postprandial gut hormone responses and glucose metabolism in cholecystectomized patients.

Preclinical studies suggest that gallbladder emptying, via bile acid-induced activation of the G protein-coupled receptor TGR5 in intestinal L cells, may play a significant role in the secretion of the incretin hormone glucagon-like peptide-1 (GLP-1) and, hence, postprandial glucose homeostasis. We examined the secretion of gut hormones in cholecystectomized subjects to test the hypothesis that gallbladder emptying potentiates postprandial release of GLP-1. Ten cholecystectomized subjects and 10 healthy, age-, gender-, and body mass index-matched control subjects received a standardized fat-rich liquid meal (2,200 kJ). Basal and postprandial plasma concentrations of glucose, insulin, C-peptide, glucagon, GLP-1, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-2 (GLP-2), cholecystokinin (CCK), and gastrin were measured. Furthermore, gastric emptying and duodenal and serum bile acids were measured. We found similar basal glucose concentrations in the two groups, whereas cholecystectomized subjects had elevated postprandial glucose excursions. Cholecystectomized subjects had reduced postprandial concentrations of duodenal bile acids, but preserved postprandial plasma GLP-1 responses, compared with control subjects. Also, cholecystectomized patients exhibited augmented fasting glucagon. Basal plasma CCK concentrations were lower and peak concentrations were higher in cholecystectomized patients. The concentrations of GIP, GLP-2, and gastrin were similar in the two groups. In conclusion, cholecystectomized subjects had preserved postprandial GLP-1 responses in spite of decreased duodenal bile delivery, suggesting that gallbladder emptying is not a prerequisite for GLP-1 release. Cholecystectomized patients demonstrated a slight deterioration of postprandial glycemic control, probably because of metabolic changes unrelated to incretin secretion.

Safety and efficacy of liraglutide versus colesevelam for the treatment of bile acid diarrhoea: a randomised, double-blind, active-comparator, non-inferiority clinical trial.

BACKGROUND: Bile acid diarrhoea is an underdiagnosed disease estimated to affect 1-2% of the general population. Case reports indicate that the glucagon-like peptide 1 receptor agonist liraglutide might be an effective treatment for bile acid diarrhoea. We aimed to investigate the safety and efficacy of liraglutide for the treatment of bile acid diarrhoea. METHODS: We conducted a randomised, double-blind, active-comparator, double-dummy, non-inferiority clinical trial at the Center for Clinical Metabolic Research at Copenhagen University Hospital-Herlev and Gentofte, Hellerup, Denmark. Patients aged 18-75 years with 75selenium-homotaurocholic acid test (SeHCAT)-verified moderate-to-severe primary bile acid diarrhoea were randomly assigned (1:1) to receive liraglutide (one daily subcutaneous injection uptitrated from 0·6-1·8 mg per day over 3 weeks) or colesevelam (three capsules of 625 mg twice daily), the standard of care, for 6 weeks following one run-in week with no treatment. The primary endpoint was the proportion of participants experiencing a reduction in daily stool frequency of 25% or greater after 6 weeks. Data from all participants were included in the analysis of the primary outcome. The non-inferiority limit was set to 15% in favour of colesevelam. This trial is registered with EudraCT (2018-003575-34) and is completed. FINDINGS: Between April 1, 2019, and Jan 31, 2021, 52 patients were enrolled; 26 were assigned to liraglutide and 26 to colesevelam. 20 (77%) of 26 participants on liraglutide and 13 (50%) of 26 on colesevelam experienced a 25% or greater reduction in stool frequency, corresponding to a significant risk difference of -27% in favour of liraglutide (one-sided 95% CI -100 to -6). Liraglutide was therefore superior to colesevelam in reducing daily stool frequency. Mild nausea with a duration of 10-21 days was reported by six participants in the liraglutide group and by one participant in the colesevelam group. No other adverse events were reported. INTERPRETATION: The superiority of liraglutide compared with colesevelam in reducing stool frequency suggests consideration of liraglutide as a potential new treatment modality for bile acid diarrhoea, although larger confirmatory trials powered for superiority are warranted. FUNDING: Novo Nordisk, Novo Nordisk Foundation, Foundation for the Advancement of Medical Science under The A.P. Møller and Chastine Mc-Kinney Møller Foundation.

MECHANISMS IN ENDOCRINOLOGY: FXR signalling: a novel target in metabolic diseases.

During the last decades, it has become clear that the gastrointestinal tract plays a pivotal role in the regulation of glucose homeostasis. More than 40 hormones originate from the gastrointestinal tract and several of these impact glucose metabolism and appetite regulation. An astonishing example of the gut's integrative role in glucose metabolism originates from investigations into bile acid biology. From primary animal studies, it has become clear that bile acids should no longer be labelled as simple detergents necessary for lipid digestion and absorption but should also be recognised as metabolic regulators implicated in lipid, glucose and energy metabolism. The nuclear farnesoid X receptor (FXR) is a part of an exquisite bile acid-sensing system that among other things ensures the optimal size of the bile acid pool. In addition, intestinal and hepatic FXR also impact the regulation of several metabolic processes such as glucose and lipid metabolism. Accordingly, natural and synthetic FXR agonists and certain FXR-regulated factors (i.e. fibroblast growth factor 19 (FGF19)) are increasingly being evaluated as treatments for metabolic diseases such as type 2 diabetes and non-alcoholic fatty liver disease (and its inflammatory version, non-alcoholic steatohepatitis). Interestingly, decreased FXR activation also benefits glucose metabolism. This can be obtained by reducing bile acid absorption using bile acid sequestering agents (approved for the treatment of type 2 diabetes) or inhibitors of intestinal bile acid transporters,that is the apical sodium-dependent bile acid transporter (ASBT). This article discusses recent clinical trials that provide insights about the role of FXR-FGF19-targetted therapy for the treatment of metabolic diseases.

A randomized, double-blind, placebo-controlled phase 1 trial of inhaled and intranasal niclosamide: A broad spectrum antiviral candidate for treatment of COVID-19.

BACKGROUND: Coronavirus disease 19 (COVID-19) is spreading globally and treatment options remain limited. A formulation of niclosamide, a potent anti-SARS-CoV-2 agent and a broad-spectrum antiviral treatment candidate, optimized for inhalation and intranasal administration (UNI91104) was developed. METHODS: We conducted a randomized, placebo-controlled, double-blind, single-centre, dose-ascending Phase 1 trial to assess the safety of UNI91104 in Denmark (NCT04576312). Healthy volunteers were randomly assigned to a ascending single dose in cohort 1-4 and five doses over 2.5 days in cohort 5. Inclusion criteria included a minimum 80% of predicted lung function. Exclusion criteria included severe, clinically significant allergies and current acute or chronic condition especially airway diseases. Safety was evaluated through adverse events (AEs) and pulmonary function tests including forced expiratory volume in one second (FEV1) and fractional exhaled nitric oxide (FeNO) tests. The primary endpoints were defined as the frequency of reported AEs and the change of safety variables relative to pre-dose. Data from all enroled healthy volunteers receiving any amount of IMP was included in the primary analyses. The pharmacokinetics of UNI91104 was determined. FINDINGS: The trial was conducted between 29 June 2020 and 08 August 2020. Thirty-four healthy volunteers received UNI91104 and ten placebo. No serious AEs or discontinuation were reported. Mild irritation in the upper respiratory tract following inhalation of UNI91104 was reported as most frequent AE (45 events in 26 healthy volunteers, 59% of all healthy volunteers). Nasal application was well-tolerated. There was no evidence of difference in the change of mean levels of pulmonary function tests between active and placebo group across all cohorts. Five healthy volunteers (11.4%) (1 on placebo) had signs of increased transient FeNO and 4 on active (9.1%) experienced asymptomatic drops in FEV1, which resolved spontaneously or were reversible with a ß2-agonist. Niclosamide exhibited dose-proportional pharmacokinetics following inhalation and intranasal administration. INTERPRETATION: UNI91104, a promising candidate for inhalation and intranasal therapy against COVID-19 and other viral respiratory tract infections is well-tolerated in healthy volunteers and warrants further testing in patient trials. FUNDING: The study was funded by Innovationsfonden Denmark and UNION therapeutics.

Glucagon-Like Peptide 2 Inhibits Postprandial Gallbladder Emptying in Man: A Randomized, Double-Blinded, Crossover Study.

INTRODUCTION: A recent study in mice points to the gut-derived hormone glucagon-like peptide 2 (GLP-2) as an important regulator of gallbladder motility inducing gallbladder relaxation and refilling. In this study, we evaluated the effect of exogenous GLP-2 on postprandial gallbladder motility in healthy men. METHODS: In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effect of 4-hour intravenous infusions of high-dose GLP-2 (10 pmol × kg × min), low-dose GLP-2 (1 pmol × kg × min), and placebo (saline) on postprandial gallbladder motility. A 300-kcal liquid-mixed meal (added 1.5 g of acetaminophen for indirect measurement of gastric emptying) was served 30 minutes after start of intravenous infusions. Gallbladder volume was assessed by ultrasonography. RESULTS: Fifteen healthy men, age 24.3 (22.4-26.1) years (mean [95% confidence interval]) and body mass index 22.5 (21.7-23.4) kg × m, were included. Basal plasma GLP-2 concentration was 14 (11-17) pmol/L. During low-dose and high-dose GLP-2 infusions, steady-state postprandial plasma GLP-2 concentrations amounted to 201 (188-214) and 2,658 (2,443-2,873) pmol/L, respectively, compared with maximum postprandial plasma GLP-2 concentration of 34 (25-44) pmol/L during placebo. Gallbladder emptying (assessed as baseline-subtracted area under the curve for gallbladder volume) was reduced by low-dose GLP-2 (-0.8 [0.7-1.9] L × min, P < 0.0001) and nearly abolished by high-dose GLP-2 (1.3 [-1.7 to 0.01] L × min, P = 0.029) compared to placebo (-2.0 [-2.8 to -1.1] L × min). Compared to placebo, gastric emptying was reduced by high-dose GLP-2 (P = 0.0060 and 0.019), whereas low-dose GLP-2 did not affect gastric emptying (P = 0.13 and 0.85). DISCUSSION: Exogenous GLP-2 exerts a dose-dependent inhibitory effect on postprandial gallbladder emptying in healthy men.