title: Comparison of Second-Phase Insulin Secretion Derived from Standard and Modified Low-Dose Graded Glucose Infusion Tests.
abstract: OBJECTIVE
  Insulin secretion has 2 phases, first-phase and second-phase insulin secretion (SPIS). The purpose of our study was to validate the SPIS derived from the modified low-dose graded glucose infusion test (MLDGGI) by using the standard SPIS derived from the low-dose graded glucose infusion test (LDGGI).
  
  
  METHODS
  Fourteen participants were enrolled. The participants underwent the LDGGI for 200 minutes and MLDGGI for 60 minutes. The LDGGI was administered using the standard Polonsky method, which entails 5 40-minute stages of glucose infusion (1, 4, 8, 6 and 24 mg/kg/min). The slopes of the insulin levels vs. the glucose levels obtained during the test were regarded as SPIS (SPIS-I). Furthermore, deconvolution was performed, and slopes of the insulin secretion rate (ISR) against glucose levels during the test (SPIS-D) were obtained and regarded as the gold standard SPIS. The MLDGGI was administered with 3 20-minute stages of glucose infusion (2, 8 and 24 mg/kg/min) for 20 minutes each. The slopes of the insulin levels vs. the glucose levels obtained during the test were regarded as SPIS (MSPIS-I). In addition, deconvolution was performed, and the slopes of the ISR against glucose levels during the test (MSPIS-D) were obtained.
  
  
  RESULTS
  Significant correlations were observed between SPIS-I and SPIS-D (r=0.843; p<0.001) and between MSPIS and SPIS-D (r=0.786; p<0.001).
  
  
  CONCLUSIONS
  SPIS could be determined simply by using the LDGGI without deconvolution. Moreover, MLDGGI was proved to be useful in estimating SPIS easily on the basis of insulin levels.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Jiunn-Diann
authors.initials: JD
authors.lastname: Lin
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chung-Ze
authors.initials: CZ
authors.lastname: Wu
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Wen-Hao
authors.initials: WH
authors.lastname: Tang
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Feng-Chih
authors.initials: FC
authors.lastname: Kuo
authors.affiliation: Department of Internal Medicine, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan.
authors.forename: Dee
authors.initials: D
authors.lastname: Pei
authors.affiliation: Associate Dean of College of Science and Engineering, Director of Graduate Institute of Applied Science and Engineering, Department and Institute of Life-Science, Fu-Jen Catholic University, New Taipei, Taiwan.
authors.forename: Yao-Jen
authors.initials: YJ
authors.lastname: Liang
authors.affiliation: Department of Pathology, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan. Electronic address: anthonypatho@gmail.com.
authors.forename: Yen-Lin
authors.initials: YL
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D005947:Glucose / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D005951:Glucose Tolerance Test; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D011379:Prognosis
chemical_list: D015415:Biomarkers; D007328:Insulin; D005947:Glucose
keywords: low-dose graded glucose infusion test; modified low-dose graded glucose infusion test; second-phase insulin secretion; seconde phase d'insulinosécretion; test de perfusion de glucose par palier de faible dose; test modifié de perfusion de glucose par palier de faible dose