protocolSection identificationModule nctId: NCT06317142, orgStudyIdInfo id: NL84574.068.23, briefTitle: Glucose and Glycogen Dynamics in Prediabetes, acronym: GGD, statusModule overallStatus: RECRUITING, startDateStruct date: 2024-02-20, primaryCompletionDateStruct date: 2025-07, completionDateStruct date: 2025-07, studyFirstPostDateStruct date: 2024-03-19, lastUpdatePostDateStruct date: 2024-04-09, sponsorCollaboratorsModule leadSponsor name: Maastricht University Medical Center, class: OTHER, descriptionModule briefSummary: The goal of this observational study is to investigate changes in nocturnal and postprandial glucose and glycogen metabolism in individuals with impaired fasting glucose and impaired glucose tolerance compared to healthy, non-diabetic, overweight participants (15 per group). In addition, it will be investigated if reducing gluconeogenesis, by using the challenge agent Acipimox, in people with prediabetes can increase glucose tolerance and fat oxidation by increased reliance on hepatic glycogen. The main questions this project aims to answer are:* whether there are differences in nocturnal glucose/glycogen metabolism in individuals with impaired fasting glucose, impaired glucose tolerance and healthy overweight controls.* whether there are differences in postprandial glucose/glycogen metabolism in individuals with impaired fasting glucose, impaired glucose tolerance and healthy overweight controls.Participants will visit the university for a screening visit and a visit with overnight stay for measurements of gluconeogenesis, glycogen, and substrate oxidation. A subgroup will receive \[18F\]-FDG to assess tissue-specific postprandial glucose uptake. Thereafter, 20 prediabetic individuals will follow a 4-day treatment with acipimox to decrease gluconeogenesis, followed by a second overnight visit with similar measurements as mentioned for the first visit., conditionsModule conditions: Pre Diabetes, designModule studyType: OBSERVATIONAL, designInfo observationalModel: CASE_CONTROL, timePerspective: CROSS_SECTIONAL, enrollmentInfo count: 45, type: ESTIMATED, armsInterventionsModule interventions name: Acipimox 250 mg Oral Capsule, outcomesModule primaryOutcomes measure: Hepatic and muscle glycogen measured by 13Carbon-Magnetic resonance spectroscopy (13C-MRS), primaryOutcomes measure: Whole body gluconeogenesis determined by deuterated water, primaryOutcomes measure: Postprandial hepatic and muscle glucose uptake determined by Fluorodeoxyglucose-Positron emission tomography ([18F]-FDG-PET) combined with oral glucose tolerance test (OGTT), secondaryOutcomes measure: Oral glucose tolerance after acipimox treatment measured by OGTT, secondaryOutcomes measure: Hepatic glycogen after acipimox treatment measured by 13C-MRS, secondaryOutcomes measure: Whole body gluconeogenesis after acipimox treatment determined by deuterated water, otherOutcomes measure: Hepatic acetylcarnitine as a measure for hepatic gluconeogenesis determined by H-MRS, otherOutcomes measure: Substrate oxidation (fat and carbohydrate oxidation) determined by indirect calorimetry, otherOutcomes measure: Dynamic water relaxation measurements with 1H-MRS (surrogate glycogen), otherOutcomes measure: Anthropometric measurements, otherOutcomes measure: Body composition determined by Bodpod, eligibilityModule sex: ALL, minimumAge: 45 Years, maximumAge: 75 Years, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule locations facility: Maastricht University, status: RECRUITING, city: Maastricht, state: Limburg, zip: 6229ER, country: Netherlands, contacts name: Kay Roumans, PhD, role: CONTACT, phone: 433882124, phoneExt: 31, email: k.roumans@maastrichtuniversity.nl, geoPoint lat: 50.84833, lon: 5.68889, hasResults: False