title: Shape of the OGTT glucose curve and risk of impaired glucose metabolism in the EGIR-RISC cohort.
abstract: OBJECTIVE
  To study whether the shape of the oral glucose tolerance test (OGTT)-glucose curve is a stable trait over time; it is associated with differences in insulin sensitivity, ß-cell function and risk of impaired fasting glucose (IFG) and glucose tolerance (IGT) in the Relationship between Insulin Sensitivity and Cardiovascular Disease (RISC) cohort.
  
  
  METHODS
  OGTT-glucose curve shape was classified as monophasic, biphasic, triphasic and anomalous in 915 individuals. Oral glucose insulin sensitivity (OGIS), Matsuda insulin sensitivity index (ISI) and ß-cell function were assessed at baseline and 3years apart.
  
  
  RESULTS
  The OGTT-glucose curve had the same baseline shape after 3years in 540 people (59%; κ=0.115; p<0.0001). Seventy percent of the participants presented with monophasic OGTT-glucose curve shape at baseline and after 3years (percent positive agreement 0.74). Baseline monophasic shape was associated with significant increased risk of IFG (OR 1.514; 95% CI 1.084-2.116; p=0.015); biphasic shape with reduced risk of IGT (OR 0.539; 95% CI 0.310-0.936) and triphasic shape with reduced risk of IFG (OR 0.493; 95% CI 0.228-1.066; P=0.043) after 3years. Increased risks of IFG (OR 1.509; 95% CI 1.008-2.260; p=0.05) and IGT (OR 1.947; 95% CI 1.085-3.494; p=0.02) were found in people who kept stable monophasic morphology over time and in switchers from biphasic to monophasic shape (OR of IGT=3.085; 95% CI 1.377-6.912; p=0.001).
  
  
  CONCLUSIONS
  After 3years follow-up, the OGTT-glucose shape was stable in 59% of the RISC cohort. Shapes were associated with different OGIS and ß-cell function; persistence over time of the monophasic shape and switch from biphasic to monophasic shape with increased risk of impaired glucose metabolism.
authors.affiliation: Bambino Gesu` Children's Hospital, IRCCS, Research Unit for Multi-factorial Diseases, Obesity and Diabetes, Rome, Italy. Electronic address: melania.manco@opbg.net.
authors.forename: Melania
authors.initials: M
authors.lastname: Manco
authors.affiliation: Institute of Applied Science and Intelligent Systems "E. Caianiello" (ISASI), National Research Council of Italy-CNR, Pozzuoli, Italy. Electronic address: g.nolfe@libero.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nolfe
authors.affiliation: Médecin-adjointe agree, Département de médecine communautaire et de premier recours; Hôpitaux Universitaires de Genève, Switzerland. Electronic address: Zoltan.pataky@hcuge.ch.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Pataky
authors.affiliation: Unità di Malattie Metaboliche Medicina 1, Istituto Scientifico San Raffaele, Milan, Italy.. Electronic address: monti.lucilla@hsr.it.
authors.forename: Lucilla
authors.initials: L
authors.lastname: Monti
authors.affiliation: DiMI, University of Perugia, Italy. Electronic address: f.porcellati@alice.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Porcellati
authors.affiliation: Instituto de Salud Carlos III., Madrid, Spain. Electronic address: Rafael.gabriel@salud.madrid.it.
authors.forename: Rafael
authors.initials: R
authors.lastname: Gabriel
authors.affiliation: Department of Clinical Therapeutics, Athens University Medical School, Athens, Greece. Electronic address: minamitrakopu@gmail.com.
authors.forename: Asimina
authors.initials: A
authors.lastname: Mitrakou
authors.affiliation: Department of Internal Medicine, Catholic University, School of Medicine, Rome, Italy. Electronic address: geltrude.mingrone@unicatt.it.
authors.forename: Geltrude
authors.initials: G
authors.lastname: Mingrone
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000378:metabolism*; D002319:Cardiovascular System; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000175:diagnosis / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012306:Risk
chemical_list: D001786:Blood Glucose
keywords: Glucose curve shape; Glucose tolerance; Insulin secretion; Insulin sensitivity; Oral glucose tolerance test