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1.
Diabetologia ; 67(7): 1260-1270, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38561463

ABSTRACT

AIMS/HYPOTHESIS: Metformin lowers postprandial glycaemic excursions in individuals with type 2 diabetes by modulating gastrointestinal function, including the stimulation of glucagon-like peptide-1 (GLP-1). The impact of varying the timing of metformin administration on postprandial glucose metabolism is poorly defined. We evaluated the effects of metformin, administered at different intervals before an intraduodenal glucose infusion, on the subsequent glycaemic, insulinaemic and GLP-1 responses in metformin-treated type 2 diabetes. METHODS: Sixteen participants with type 2 diabetes that was relatively well-controlled by metformin monotherapy were studied on four separate days in a crossover design. On each day, participants were randomised to receive a bolus infusion of metformin (1000 mg in 50 ml 0.9% saline) via a nasoduodenal catheter at t = -60, -30 or 0 min (and saline at the other timepoints) or saline at all timepoints (control), followed by an intraduodenal glucose infusion of 12.56 kJ/min (3 kcal/min) at t = 0-60 min. The treatments were blinded to both participants and investigators involved in the study procedures. Plasma glucose, insulin and total GLP-1 levels were measured every 30 min between t = -60 min and t = 120 min. RESULTS: There was a treatment-by-time interaction for metformin in reducing plasma glucose levels and increasing plasma GLP-1 and insulin levels (p<0.05 for each). The reduction in plasma glucose levels was greater when metformin was administered at t = -60 or -30 min vs t = 0 min (p<0.05 for each), and the increases in plasma GLP-1 levels were evident only when metformin was administered at t = -60 or -30 min (p<0.05 for each). Although metformin did not influence insulin sensitivity, it enhanced glucose-induced insulin secretion (p<0.05), and the increases in plasma insulin levels were comparable on the 3 days when metformin was given. CONCLUSIONS/INTERPRETATION: In well-controlled metformin-treated type 2 diabetes, glucose-lowering by metformin is greater when it is given before, rather than with, enteral glucose, and this is associated with a greater GLP-1 response. These observations suggest that administration of metformin before meals may optimise its effect in improving postprandial glycaemic control. TRIAL REGISTRATION: www.anzctr.org.au ACTRN12621000878875 FUNDING: The study was not funded by a specific research grant.


Subject(s)
Blood Glucose , Cross-Over Studies , Diabetes Mellitus, Type 2 , Glucagon-Like Peptide 1 , Glucose , Hypoglycemic Agents , Metformin , Humans , Metformin/therapeutic use , Metformin/administration & dosage , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/blood , Male , Glucagon-Like Peptide 1/blood , Blood Glucose/drug effects , Blood Glucose/metabolism , Female , Middle Aged , Double-Blind Method , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/therapeutic use , Glucose/metabolism , Insulin/blood , Aged , Adult , Postprandial Period , Duodenum/metabolism , Duodenum/drug effects
2.
Am J Physiol Endocrinol Metab ; 326(4): E537-E544, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38477876

ABSTRACT

There is increasing evidence linking bitter taste receptor (BTR) signaling to gut hormone secretion and glucose homeostasis. However, its effect on islet hormone secretion has been poorly characterized. This study investigated the effect of the bitter substance, denatonium benzoate (DB), on hormone secretion from mouse pancreatic islets and INS-1 832/13 cells. DB (0.5-1 mM) augmented insulin secretion at both 2.8 mM and 16.7 mM glucose. This effect was no longer present at 5 mM DB likely due to the greater levels of cellular apoptosis. DB-stimulated insulin secretion involved closure of the KATP channel, activation of T2R signaling in beta-cells, and intraislet glucagon-like peptide-1 (GLP-1) release. DB also enhanced glucagon and somatostatin secretion, but the underlying mechanism was less clear. Together, this study demonstrates that the bitter substance, DB, is a strong potentiator of islet hormone secretion independent of glucose. This observation highlights the potential for widespread off-target effects associated with the clinical use of bitter-tasting substances.NEW & NOTEWORTHY We show that the bitter substance, denatonium benzoate (DB), stimulates insulin, glucagon, somatostatin, and GLP-1 secretion from pancreatic islets, independent of glucose, and that DB augments insulin release via the KATP channel, bitter taste receptor signaling, and intraislet GLP-1 secretion. Exposure to a high dose of DB (5 mM) induces cellular apoptosis in pancreatic islets. Therefore, clinical use of bitter substances to improve glucose homeostasis may have unintended negative impacts beyond the gut.


Subject(s)
Islets of Langerhans , Quaternary Ammonium Compounds , Taste , Mice , Animals , Glucagon/pharmacology , Insulin/pharmacology , Glucose/pharmacology , Glucagon-Like Peptide 1/pharmacology , Somatostatin/pharmacology , Adenosine Triphosphate/pharmacology
3.
J Child Psychol Psychiatry ; 65(2): 176-187, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37571996

ABSTRACT

BACKGROUND: Low socioeconomic status (SES) is associated with increased risk for emotional and behavioural problems among children. Evidence from twin studies has shown that family SES moderates genetic and environmental influences on child mental health. However, it is also known that SES is itself under genetic influence and previous gene-environment interaction (G×E) studies have not incorporated the potential genetic overlap between child mental health and family SES into G×E analyses. We applied a novel approach using extended family data to investigate the moderation of aetiological influences on child emotional and behavioural problems by parental socioeconomic status in the presence of modelled gene-environment correlation. METHODS: The sample comprised >28,100 children in extended-family units drawn from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mothers reported children's emotional and behavioural symptoms. Parents' income and educational attainment were obtained through linkage to administrative register data. Bivariate moderation Multiple-Children-of-Twins-and-Siblings (MCoTS) models were used to analyse relationships between offspring outcomes (emotional and behavioural symptom scores) and parental socioeconomic moderators (income rank and educational attainment). RESULTS: The aetiology of child emotional symptoms was moderated by maternal and paternal educational attainment. Shared environmental influences on child emotional symptoms were greater at lower levels of parents' education. The aetiology of child behavioural symptoms was moderated by maternal, but not paternal, socioeconomic factors. Genetic factors shared between maternal income and child behavioural symptoms were greater in families with lower levels maternal income. Nonshared environmental influences on child behavioural symptoms were greater in families with higher maternal income and education. CONCLUSIONS: Parental socioeconomic indicators moderated familial influences and nonshared environmental influences on child emotional and behavioural outcomes. Maternal SES and child mental health share aetiological overlap such that shared genetic influence was greater at the lower end of the socioeconomic distribution. Our findings collectively highlight the role that family socioeconomic factors play in shaping the origins of child emotional and behavioural problems.


Subject(s)
Gene-Environment Interaction , Mothers , Female , Humans , Male , Mothers/psychology , Cohort Studies , Extended Family , Social Class , Fathers
4.
Diabetes Obes Metab ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38698647

ABSTRACT

AIM: To evaluate gastric emptying (GE) and the glycaemic response to a 75-g oral glucose load in newly diagnosed, treatment-naïve Han Chinese with type 2 diabetes (T2D) before insulin pump therapy, after 4 weeks of insulin pump therapy, and 12-15 months after insulin pump therapy. MATERIALS AND METHODS: Twenty participants with T2D (baseline glycated haemoglobin [± SD] 10.7% [± 1.2%] 93 [± 10] mmol/mol) ingested a 75-g glucose drink containing 150 mg 13C-acetate, to determine the gastric half-emptying time, and underwent assessment of plasma glucose and serum insulin, C-peptide and glucagon-like peptide-1 (GLP-1) over 180 min before and after 4 weeks of insulin pump therapy (discontinued for 48 h before re-assessment). Data were compared to those in 19 healthy participants matched for sex and age. After 12-15 months, GE was re-measured in 14 of the T2D participants. RESULTS: At baseline, participants with T2D exhibited substantially augmented fasting and post-glucose glycaemia, diminished insulin secretion, and more rapid GE (p < 0.05 each), but comparable GLP-1, compared to healthy participants. Following insulin pump therapy, insulin secretion increased, GLP-1 secretion was attenuated, fasting and post-glucose glycaemia were lower, and GE was slowed (p < 0.05 each). The slowing of GE in T2D participants was sustained over 12-15 months of follow-up. CONCLUSIONS: In newly diagnosed Han Chinese with T2D, GE is often accelerated despite poor glycaemic control and is slowed by short-term insulin pump therapy. The effect on GE is maintained for at least 12 months.

5.
Diabetes Obes Metab ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38698649

ABSTRACT

AIM: To evaluate sex differences in gastric emptying and the glycaemic response to a glucose drink and a high carbohydrate meal in type 2 diabetes (T2D). METHODS: In cohort 1, 70 newly diagnosed, treatment-naïve Chinese patients with T2D (44 men) recruited from a diabetes outpatient clinic ingested a 75-g glucose drink containing 150 mg 13C-acetate. In cohort 2, 101 Australian patients with T2D (67 male) recruited from the community, managed by diet and/or metformin monotherapy, ingested a semi-solid mashed potato meal, labelled with 100 µl 13C-octanoic acid. Breath samples were collected over 3 and 4 h, respectively, for assessment of gastric emptying, and venous blood was sampled for evaluation of glycaemia (with and without adjustment for each participant's estimated total blood volume). RESULTS: Gastric emptying was slower in female than male subjects in both cohorts (both p < .01). Multiple linear regression analyses revealed that gastric emptying was independently associated with sex (both p < .05). Without adjustment for blood volume, the glycaemic responses to oral glucose and the mixed meal were greater in female subjects (both p < .001). However, after adjustment for blood volume, the glycaemic responses were greater in men (both p < .05). CONCLUSIONS: Gastric emptying is slower in women than men with T2D, associated with a reduced blood volume-adjusted glycaemic response to oral glucose and a mixed meal in women. These observations highlight the sex difference in postprandial glucose handling, which is relevant to the personalized management of postprandial glycaemia in T2D.

6.
Article in English | MEDLINE | ID: mdl-38812101

ABSTRACT

BACKGROUND AND AIM: Rates of antimicrobial-resistant Helicobacter pylori infection are rising globally, but little is known about contemporary resistance patterns, virulence factors, and phylogenetic patterns of isolates within Australia. We aimed to characterize antimicrobial resistance and genetic mutations associated with adverse clinical outcomes. METHODS: Whole genome sequencing, culturing, and antibiotic sensitivity data for refractory H. pylori isolates at Australian centers were collected between 2013 and 2022. Phylogenetic origins, antibiotic resistance mutations, and virulence factors were examined with phenotypic resistance profiles. RESULTS: One hundred thirty-five isolates underwent culture, with 109 of these undergoing whole genome sequencing. Forty-three isolates were isolated from patients in South Australia and 66 from Western Australia. Isolates originated primarily from hpEurope (59.6%), hpEastAsia (25.7%), and hpNEAfrica (6.4%). Antimicrobial resistance to clarithromycin was seen in 85% of isolates, metronidazole in 52%, levofloxacin in 18%, rifampicin in 14%, and amoxicillin in 9%. Most isolates (59%) were multi-drug resistant. Resistance concordance between genetically determined resistance and phenotypic resistance was 92% for clarithromycin and 94% for levofloxacin. Analysis of virulence factors demonstrated cag pathogenicity island (cagPAI) in 67% of isolates and cagA in 61%, correlating with isolate genetic origin. The most virulent s1m1 vacuolating cytotoxin A genotype was present in 26% of isolates. CONCLUSION: Refractory H. pylori isolates in Australia emanate from multiple global origins. Strong concordance between genetic and phenotypic antibiotic resistance profiles raises the possibility of utilizing genetic profiling in clinical practice. The dynamic landscape of H. pylori in Australia warrants the establishment of a national database to monitor H. pylori resistance and evolving virulence.

7.
Psychol Med ; 53(13): 6183-6193, 2023 10.
Article in English | MEDLINE | ID: mdl-36510471

ABSTRACT

BACKGROUND: There is substantial variation in patient symptoms following psychological therapy for depression and anxiety. However, reliance on endpoint outcomes ignores additional interindividual variation during therapy. Knowing a patient's likely symptom trajectories could guide clinical decisions. We aimed to identify latent classes of patients with similar symptom trajectories over the course of psychological therapy and explore associations between baseline variables and trajectory class. METHODS: Patients received high-intensity psychological treatment for common mental health problems at National Health Service Improving Access to Psychological Therapies services in South London (N = 16 258). To identify trajectories, we performed growth mixture modelling of depression and anxiety symptoms over 11 sessions. We then ran multinomial regressions to identify baseline variables associated with trajectory class membership. RESULTS: Trajectories of depression and anxiety symptoms were highly similar and best modelled by four classes. Three classes started with moderate-severe symptoms and showed (1) no change, (2) gradual improvement, and (3) fast improvement. A final class (4) showed initially mild symptoms and minimal improvement. Within the moderate-severe baseline symptom classes, patients in the two showing improvement as opposed to no change tended not to be prescribed psychotropic medication or report a disability and were in employment. Patients showing fast improvement additionally reported lower baseline functional impairment on average. CONCLUSIONS: Multiple trajectory classes of depression and anxiety symptoms were associated with baseline characteristics. Identifying the most likely trajectory for a patient at the start of treatment could inform decisions about the suitability and continuation of therapy, ultimately improving patient outcomes.


Subject(s)
Depression , Mental Health , Humans , Depression/psychology , State Medicine , Anxiety/therapy , Anxiety Disorders/therapy
8.
Diabetes Obes Metab ; 25(7): 1849-1854, 2023 07.
Article in English | MEDLINE | ID: mdl-36864654

ABSTRACT

AIM: To evaluate the effect of gastric distension, induced using a gastric 'barostat', on the secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) in the presence and absence of small intestinal nutrients in healthy individuals. MATERIALS AND METHODS: Eight healthy participants (two females, six males, mean age 69.3 ± 1.2 years, body mass index 23.5 ± 0.8 kg/m2 ) were each studied on four occasions when they received an intraduodenal infusion of either (i) 0.9% saline or (ii) glucose delivered at a rate of 3 kcal/min both with, and without, an intragastric balloon with the pressure set to 8 mmHg above the intragastric minimum distending pressure. RESULTS: Following intraduodenal saline or glucose infusion, there was no difference in plasma GLP-1 with or without gastric distension (P = 1.00 for both saline and glucose infusions). There was also no difference in plasma GIP with or without gastric distension (P = 1.00 for saline infusion and P = .99 for glucose infusion). CONCLUSIONS: Gastric distension, either alone or during small intestinal glucose exposure, does not stimulate incretin hormone secretion significantly in healthy humans.


Subject(s)
Gastric Balloon , Glucose , Male , Female , Humans , Aged , Incretins , Cross-Over Studies , Blood Glucose , Saline Solution , Gastric Inhibitory Polypeptide , Glucagon-Like Peptide 1 , Insulin
9.
Diabetes Obes Metab ; 25(9): 2447-2456, 2023 09.
Article in English | MEDLINE | ID: mdl-37380614

ABSTRACT

AIMS: To address the need for noninvasive alternatives to metabolic surgery or duodenal exclusion devices for the management of type 2 diabetes (T2D) and obesity by developing an orally administered therapeutic polymer, GLY-200, designed to bind to and enhance the barrier function of mucus in the gastrointestinal tract to establish duodenal exclusion noninvasively. MATERIALS AND METHODS: A Phase 1, randomized, double-blind, placebo-controlled, single- (SAD) and multiple-ascending-dose (MAD) healthy volunteer study was conducted. In the SAD arm, four cohorts received a single dose of 0.5 g up to 6.0 g GLY-200 or placebo, while in the MAD arm, four cohorts received 5 days of twice-daily or three-times-daily dosing (total daily dose 2.0 g up to 6.0 g GLY-200 or placebo). Assessments included safety and tolerability (primary) and exploratory pharmacodynamics, including serum glucose, insulin, bile acids and gut hormones. RESULTS: No safety signals were observed; tolerability signals were limited to mild to moderate dose-dependent gastrointestinal events. In the MAD arm (Day 5), reductions in glucose and insulin and increases in bile acids, glucagon-like peptide-1, peptide YY and glicentin, were observed following a nonstandardized meal in subjects receiving twice-daily dosing of 2.0 g GLY-200 (N = 9) versus those receiving placebo (N = 8). CONCLUSIONS: GLY-200 is safe and generally well tolerated at doses of ≤2.0 g twice daily. Pharmacodynamic results mimic the biomarker signature observed after Roux-en-Y gastric bypass and duodenal exclusion devices, indicating a pharmacological effect in the proximal small intestine. This study represents the first clinical demonstration that duodenal exclusion can be achieved with an oral drug and supports further development of GLY-200 for the treatment of obesity and/or T2D.


Subject(s)
Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Insulin/therapeutic use , Bile Acids and Salts , Blood Glucose/metabolism , Insulin, Regular, Human/therapeutic use , Glucose/therapeutic use , Obesity/drug therapy , Double-Blind Method
10.
BMC Psychiatry ; 23(1): 542, 2023 07 26.
Article in English | MEDLINE | ID: mdl-37495971

ABSTRACT

BACKGROUND: The Genetic Links to Anxiety and Depression (GLAD) Study is a large cohort of individuals with lifetime anxiety and/or depression, designed to facilitate re-contact of participants for mental health research. At the start of the pandemic, participants from three cohorts, including the GLAD Study, were invited to join the COVID-19 Psychiatry and Neurological Genetics (COPING) study to monitor mental and neurological health. However, previous research suggests that participation in longitudinal studies follows a systematic, rather than random, process, which can ultimately bias results. Therefore, this study assessed participation biases following the re-contact of GLAD Study participants. METHODS: In April 2020, all current GLAD Study participants (N = 36,770) were invited to the COPING study. Using logistic regression, we investigated whether sociodemographic, mental, and physical health characteristics were associated with participation in the COPING baseline survey (aim one). Subsequently, we used a zero-inflated negative binomial regression to examine whether these factors were also related to participation in the COPING follow-up surveys (aim two). RESULTS: For aim one, older age, female gender identity, non-binary or self-defined gender identities, having one or more physical health disorders, and providing a saliva kit for the GLAD Study were associated with an increased odds of completing the COPING baseline survey. In contrast, lower educational attainment, Asian or Asian British ethnic identity, Black or Black British ethnic identity, higher alcohol consumption at the GLAD sign-up survey, and current or ex-smoking were associated with a reduced odds. For aim two, older age, female gender, and saliva kit provision were associated with greater COPING follow-up survey completion. Lower educational attainment, higher alcohol consumption at the GLAD Study sign-up, ex-smoking, and self-reported attention deficit hyperactivity disorder had negative relationships. CONCLUSIONS: Participation biases surrounding sociodemographic and physical health characteristics were particularly evident when re-contacting the GLAD Study volunteers. Factors associated with participation may vary depending on study design. Researchers should examine the barriers and mechanisms underlying participation bias in order to combat these issues and address recruitment biases in future studies.


Subject(s)
COVID-19 , Mental Health , Humans , Male , Female , Depression , Gender Identity , Anxiety
11.
Intern Med J ; 53(11): 1972-1978, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37705320

ABSTRACT

BACKGROUND AND AIM: Helicobacter pylori infection is responsible for considerable morbidity and mortality worldwide and eradication rates are falling globally because of increasing antimicrobial resistance. However, there is a paucity of local data to guide the choice of eradication therapy in Australia. This study aimed to evaluate current Australian rates of H. pylori antibiotic resistance in patients who had failed prior eradication therapy. METHODS: A retrospective analysis of routine culture and antibiotic susceptibility data from two pathology laboratories servicing multiple tertiary referral hospitals in Western Australia (WA) and South Australia (SA), between 2018 and 2022, was performed. Rates of antimicrobial resistance and prevalence of multiresistant isolates in both SA and WA were calculated and comparison of temporal trends and differences between the two states was conducted. RESULTS: A total of 796 H. pylori isolates revealed a clarithromycin resistance rate of 82%, metronidazole 68%, amoxicillin 4.4% and tetracycline 0.5%. Resistance to levofloxacin was observed in 22% and rifampicin 14%. Rates of resistance to clarithromycin were lower in SA compared with WA (incidence rate ratio [IRR]: 0.69, P = 0.0001). Multiresistant isolates were discovered in 63% of patients, with lower rates in SA compared with WA (IRR: 0.74, P = 0.002). CONCLUSION: This first multicentre, multistate study of H. pylori resistance in Australian patients exposed to prior therapy demonstrated high rates of antimicrobial resistance, including levofloxacin (>20%). This raises concern about recommending levofloxacin in empirical second-line therapies. Increased monitoring and awareness of current H. pylori resistance rates in Australia are needed to guide local eradication practices.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Humans , Amoxicillin , Anti-Bacterial Agents/pharmacology , Australia/epidemiology , Clarithromycin/pharmacology , Drug Resistance, Bacterial , Helicobacter Infections/drug therapy , Helicobacter Infections/epidemiology , Levofloxacin , Metronidazole/pharmacology , Microbial Sensitivity Tests , Retrospective Studies
12.
Intern Med J ; 53(8): 1311-1320, 2023 08.
Article in English | MEDLINE | ID: mdl-37189293

ABSTRACT

Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) reduce elevated blood glucose levels and induce weight loss. Multiple GLP-1 RAs and one combined GLP-1/glucose-dependent insulinotropic polypeptide agonist are currently available. This review was conducted with the aim of summarising direct comparisons between subcutaneous semaglutide and other GLP-1 RAs in individuals with type 2 diabetes (T2D), particularly with respect to efficacy for inducing weight loss and improving other markers of metabolic health. This systematic review of PubMed and Embase from inception to early 2022 was registered on PROSPERO and was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology guidelines. Of the 740 records identified in the search, five studies fulfilled the inclusion criteria. Comparators included liraglutide, exenatide, dulaglutide and tirzepatide. In the identified studies, multiple dosing regimens were utilised for semaglutide. Randomised trials support the superior efficacy of semaglutide over other GLP-1 RAs with respect to weight loss in T2D, but tirzepatide is more effective than semaglutide.


Subject(s)
Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Glucagon-Like Peptide 1 , Weight Loss , Observational Studies as Topic
13.
Diabetologia ; 65(12): 1981-1993, 2022 12.
Article in English | MEDLINE | ID: mdl-36194250

ABSTRACT

Gastric emptying is a major determinant of postprandial blood glucose, accounting for ~35% of variance in peak glucose in both healthy individuals and those with type 2 diabetes. Gastric emptying is frequently disordered in individuals with diabetes (both abnormally delayed and accelerated). Delayed gastric emptying, i.e. diabetic gastroparesis, may be linked to upper gastrointestinal symptoms for which current treatment remains suboptimal; pharmacological acceleration of delayed emptying is only weakly associated with symptom improvement. Accordingly, the relationship between symptoms and delayed gastric emptying is not simply 'cause and effect'. In insulin-treated patients, disordered gastric emptying, even when not associated with gastrointestinal symptoms, can cause a mismatch between the onset of insulin action and the availability of absorbed carbohydrate, leading to suboptimal glycaemic control. In patients with type 2 diabetes, interventions that slow gastric emptying, e.g. glucagon-like peptide-1 receptor agonists, reduce postprandial blood glucose. This review focuses on recent insights into the impact of gastric emptying on postprandial blood glucose, effects of diabetes therapy on gastric emptying and the management of disordered gastric emptying in diabetes. In view of the broad relevance of gastric emptying to diabetes management, it is important that future clinical trials evaluating novel therapies that may affect gastric emptying should quantify the latter with an appropriate technique, such as scintigraphy or a stable isotope breath test.


Subject(s)
Diabetes Mellitus, Type 2 , Gastroparesis , Humans , Blood Glucose , Gastroparesis/drug therapy , Gastroparesis/etiology , Glycemic Control , Gastric Emptying , Postprandial Period , Insulin
14.
Gastroenterology ; 161(2): 536-547.e2, 2021 08.
Article in English | MEDLINE | ID: mdl-33848536

ABSTRACT

OBJECTIVE: Hypothalamic melanocortin 4 receptors (MC4R) are a key regulator of energy homeostasis. Brain-penetrant MC4R agonists have failed, as concentrations required to suppress food intake also increase blood pressure. However, peripherally located MC4R may also mediate metabolic benefits of MC4R activation. Mc4r transcript is enriched in mouse enteroendocrine L cells and peripheral administration of the endogenous MC4R agonist, α-melanocyte stimulating hormone (α-MSH), triggers the release of the anorectic hormones Glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) in mice. This study aimed to determine whether pathways linking MC4R and L-cell secretion exist in humans. DESIGN: GLP-1 and PYY levels were assessed in body mass index-matched individuals with or without loss-of-function MC4R mutations following an oral glucose tolerance test. Immunohistochemistry was performed on human intestinal sections to characterize the mucosal MC4R system. Static incubations with MC4R agonists were carried out on human intestinal epithelia, GLP-1 and PYY contents of secretion supernatants were assayed. RESULTS: Fasting PYY levels and oral glucose-induced GLP-1 secretion were reduced in humans carrying a total loss-of-function MC4R mutation. MC4R was localized to L cells and regulates GLP-1 and PYY secretion from ex vivo human intestine. α-MSH immunoreactivity in the human intestinal epithelia was predominantly localized to L cells. Glucose-sensitive mucosal pro-opiomelanocortin cells provide a local source of α-MSH that is essential for glucose-induced GLP-1 secretion in small intestine. CONCLUSION: Our findings describe a previously unidentified signaling nexus in the human gastrointestinal tract involving α-MSH release and MC4R activation on L cells in an autocrine and paracrine fashion. Outcomes from this study have direct implications for targeting mucosal MC4R to treat human metabolic disorders.


Subject(s)
Enteroendocrine Cells/metabolism , Glucagon-Like Peptide 1/metabolism , Intestinal Mucosa/metabolism , Peptide YY/metabolism , Pro-Opiomelanocortin/metabolism , Receptor, Melanocortin, Type 4/metabolism , alpha-MSH/metabolism , Autocrine Communication , Blood Glucose/metabolism , Case-Control Studies , Enteroendocrine Cells/drug effects , Glucose/administration & dosage , Glucose Tolerance Test , Humans , Intestinal Mucosa/drug effects , Loss of Function Mutation , Paracrine Communication , Pro-Opiomelanocortin/genetics , Receptor, Melanocortin, Type 4/agonists , Receptor, Melanocortin, Type 4/genetics , Secretory Pathway , Signal Transduction , Time Factors , alpha-MSH/pharmacology
15.
Diabetes Obes Metab ; 24(8): 1656-1660, 2022 08.
Article in English | MEDLINE | ID: mdl-35491529

ABSTRACT

Cholecystectomy has been reported to be associated with increased risk of diabetes in cross-sectional studies. In the current study, we performed both cross-sectional and prospective analyses to examine the association between cholecystectomy and dysglycaemia in Chinese community-dwelling adults. A total of 1612 participants (n = 1564 without cholecystectomy and n = 48 with cholecystectomy) were evaluated for glycaemic status (according to the World Health Organization (WHO) 1999 criteria) and then followed up over ~3.2 years. Percent changes (Δ) in fasting blood glucose and HbA1c from baseline at the follow-up visit were calculated to define glycaemic control as stable (-10% ≤ Δ < 10%), improved (Δ < -10%), or worsened (Δ ≥ 10%). The baseline cross-sectional analyses indicated that cholecystectomy was associated with an increased risk of both prediabetes and diabetes, while the prospective analysis indicated that cholecystectomy was also associated with a greater risk of deterioration in glycaemic control (ΔFPG ≥10% and ΔHbA1c ≥10%) (P < 0.05 for each, both before and after adjusting for potential confounding covariates). These observations suggest that individuals in the Chinese community-dwelling population who have undergone cholecystectomy are at increased risk of dysglycaemia. Further studies are warranted to both delineate the underlying mechanisms and to clarify whether more intense surveillance for future development of diabetes is needed in this group.


Subject(s)
Diabetes Mellitus , Prediabetic State , Adult , Blood Glucose , Cholecystectomy/adverse effects , Cross-Sectional Studies , Diabetes Mellitus/epidemiology , Diabetes Mellitus/etiology , Glycated Hemoglobin , Humans , Prediabetic State/complications , Prediabetic State/epidemiology
16.
Diabetes Obes Metab ; 24(6): 1132-1142, 2022 06.
Article in English | MEDLINE | ID: mdl-35238131

ABSTRACT

AIM: To determine the serum bile acid (BA) response to 75-g oral glucose in individuals without diabetes, and whether this is attenuated in patients with 'early' type 2 diabetes (T2D) and related to the glycaemic response at 2 hours in either group. METHODS: Forty newly diagnosed, treatment-naïve Han Chinese T2D subjects and 40 age-, gender-, and body mass index-matched controls without T2D ingested a 75-g glucose drink after an overnight fast. Plasma glucose and serum concentrations of total and individual BAs, fibroblast growth factor-19 (FGF-19), total glucagon-like peptide-1 (GLP-1), and insulin, were measured before and 2 hours after oral glucose. RESULTS: Fasting total BA levels were higher in T2D than control subjects (P < .05). At 2 hours, the BA profile exhibited a shift from baseline in both groups, with increases in conjugated BAs and/or decreases in unconjugated BAs. There were increases in total BA and FGF-19 levels in control (both P < .05), but not T2D, subjects. Plasma glucose concentrations at 2 hours related inversely to serum total BA levels in control subjects (r = -0.42, P = .006). Total GLP-1 and the insulin/glucose ratio were increased at 2 hours in both groups, and the magnitude of the increase was greater in control subjects. CONCLUSIONS: The serum BA response to a 75-g oral glucose load is attenuated in patients with 'early' T2D, as is the secretion of FGF-19 and GLP-1, while in individuals without T2D it correlates with 2-hour plasma glucose levels. These observations support a role for BAs in the regulation of postprandial glucose metabolism.


Subject(s)
Blood Glucose , Diabetes Mellitus, Type 2 , Bile Acids and Salts , Blood Glucose/metabolism , Fibroblast Growth Factors , Glucagon-Like Peptide 1 , Glucose/metabolism , Humans , Insulin
17.
J Gastroenterol Hepatol ; 37(7): 1263-1274, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35315547

ABSTRACT

BACKGROUND AND AIM: Rates of antimicrobial-resistant Helicobacter pylori infection are rising globally; however, geospatial location and its interaction with risk factors for infection have not been closely examined. METHODS: Gastric biopsy specimens were collected to detect H. pylori infection at multiple centers in Adelaide, South Australia, between 1998 and 2017. The geospatial distribution of antibiotic-resistant H. pylori in the Greater Adelaide region was plotted using choropleth maps. Moran's I was used to assess geospatial correlation, and multivariate linear regression (MLR) was used to examine associations between migration status, socioeconomic status, age, gender, and rates of H. pylori positivity and antibiotic resistance. Geographically weighted regression (GWR) was used to determine the extent to which the associations varied according to geospatial location. RESULTS: Of 20 108 biopsies across 136 postcodes within the Greater Adelaide region, 1901 (9.45%) were H. pylori positive. Of these, 797 (41.9%) displayed clarithromycin, tetracycline, metronidazole, or amoxicillin resistance. In MLR, migration status was associated with the rate of H. pylori positivity (ß = 3.85% per 10% increase in a postcode's migrant population; P < 0.001). H. pylori positivity and resistance to any antibiotic were geospatially clustered (Moran's I = 0.571 and 0.280, respectively; P < 0.001 for both). In GWR, there was significant geospatial variation in the strength of the migrant association for both H. pylori positivity and antibiotic resistance. CONCLUSION: Our study demonstrates the heterogeneous geospatial distribution of H. pylori positivity and antibiotic resistance, as well as its interaction with migrant status. Geographic location and migrant status are important factors to consider for H. pylori eradication therapy.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Amoxicillin/therapeutic use , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Clarithromycin , Drug Resistance, Bacterial , Helicobacter Infections/drug therapy , Helicobacter Infections/epidemiology , Humans , Metronidazole , Microbial Sensitivity Tests , South Australia/epidemiology
18.
BMC Psychiatry ; 22(1): 719, 2022 11 18.
Article in English | MEDLINE | ID: mdl-36401199

ABSTRACT

BACKGROUND: Progress towards stratified care for anxiety and depression will require the identification of new predictors. We collected data on retrospectively self-reported therapeutic outcomes in adults who received psychological therapy in the UK in the past ten years. We aimed to replicate factors associated with traditional treatment outcome measures from the literature. METHODS: Participants were from the Genetic Links to Anxiety and Depression (GLAD) Study, a UK-based volunteer cohort study. We investigated associations between retrospectively self-reported outcomes following therapy, on a five-point scale (global rating of change; GRC) and a range of sociodemographic, clinical and therapy-related factors, using ordinal logistic regression models (n = 2890). RESULTS: Four factors were associated with therapy outcomes (adjusted odds ratios, OR). One sociodemographic factor, having university-level education, was associated with favourable outcomes (OR = 1.37, 95%CI: 1.18, 1.59). Two clinical factors, greater number of reported episodes of illness (OR = 0.95, 95%CI: 0.92, 0.97) and higher levels of personality disorder symptoms (OR = 0.89, 95%CI: 0.87, 0.91), were associated with less favourable outcomes. Finally, reported regular use of additional therapeutic activities was associated with favourable outcomes (OR = 1.39, 95%CI: 1.19, 1.63). There were no statistically significant differences between fully adjusted multivariable and unadjusted univariable odds ratios. CONCLUSION: Therapy outcome data can be collected quickly and inexpensively using retrospectively self-reported measures in large observational cohorts. Retrospectively self-reported therapy outcomes were associated with four factors previously reported in the literature. Similar data collected in larger observational cohorts may enable detection of novel associations with therapy outcomes, to generate new hypotheses, which can be followed up in prospective studies.


Subject(s)
Depression , Depressive Disorder , Adult , Humans , Depression/therapy , Self Report , Cohort Studies , Prospective Studies , Retrospective Studies , Anxiety/psychology , Treatment Outcome
19.
Intern Med J ; 52(9): 1554-1560, 2022 09.
Article in English | MEDLINE | ID: mdl-34865299

ABSTRACT

BACKGROUND: Helicobacter pylori infection is responsible for considerable morbidity and mortality worldwide, and eradication rates are falling in many countries, primarily due to clarithromycin and metronidazole resistance. AIMS: There is a paucity of contemporary Australian data, which we sought to address by evaluating local rates of resistance of H. pylori to amoxicillin, clarithromycin, metronidazole and tetracycline over the past 20 years. METHODS: All gastric biopsy specimens collected at endoscopy to detect H. pylori infection at a single centre underwent routine culture and antibiotic susceptibility testing between 1998 and 2017. Specimens from 12 842 patients were cultured for H. pylori, of which 1473 positive cultures were tested for antibiotic susceptibility. RESULTS: Antibiotic resistance to clarithromycin increased by 3.7% per year (incidence rate ratio [IRR] 1.037; P = 0.014) over 20 years, with a corresponding 5.0% annual increase in minimum inhibitory concentration (MIC) (odds ratio 1.050; P < 0.001). Since 2010, average clarithromycin resistance has exceeded 20%, with >25% of isolates resistant in the past 2 years of data capture. In contrast, rates of resistance to metronidazole (35.3%), amoxicillin (0.14%) and tetracycline (0.34%) and their MIC have remained stable. Review of a representative sample (n = 120; 8%) of these patients revealed that only 5% had documented prior H. pylori eradication therapy. CONCLUSIONS: Over the past 20 years there has been a substantial rise in clarithromycin resistance, with stable metronidazole resistance and low rates of resistance to amoxicillin and tetracycline. Current first-line H. pylori eradication therapy may fail to achieve adequate eradication rates, and optimal first-line therapy in Australia should be revisited.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Amoxicillin/pharmacology , Amoxicillin/therapeutic use , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Australia/epidemiology , Clarithromycin/pharmacology , Drug Resistance, Bacterial , Helicobacter Infections/drug therapy , Helicobacter Infections/epidemiology , Humans , Metronidazole/pharmacology , Metronidazole/therapeutic use , Microbial Sensitivity Tests , Tetracycline/pharmacology , Tetracycline/therapeutic use
20.
Mol Psychiatry ; 25(7): 1430-1446, 2020 07.
Article in English | MEDLINE | ID: mdl-31969693

ABSTRACT

Depression is more frequent among individuals exposed to traumatic events. Both trauma exposure and depression are heritable. However, the relationship between these traits, including the role of genetic risk factors, is complex and poorly understood. When modelling trauma exposure as an environmental influence on depression, both gene-environment correlations and gene-environment interactions have been observed. The UK Biobank concurrently assessed Major Depressive Disorder (MDD) and self-reported lifetime exposure to traumatic events in 126,522 genotyped individuals of European ancestry. We contrasted genetic influences on MDD stratified by reported trauma exposure (final sample size range: 24,094-92,957). The SNP-based heritability of MDD with reported trauma exposure (24%) was greater than MDD without reported trauma exposure (12%). Simulations showed that this is not confounded by the strong, positive genetic correlation observed between MDD and reported trauma exposure. We also observed that the genetic correlation between MDD and waist circumference was only significant in individuals reporting trauma exposure (rg = 0.24, p = 1.8 × 10-7 versus rg = -0.05, p = 0.39 in individuals not reporting trauma exposure, difference p = 2.3 × 10-4). Our results suggest that the genetic contribution to MDD is greater when reported trauma is present, and that a complex relationship exists between reported trauma exposure, body composition, and MDD.


Subject(s)
Databases, Factual , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/genetics , Gene-Environment Interaction , Genetic Predisposition to Disease/genetics , Genome-Wide Association Study , Psychological Trauma/epidemiology , Self Report , Adult , Aged , Female , Humans , Male , Middle Aged , United Kingdom/epidemiology , Waist Circumference
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