title: Insulin Secretory Defect and Insulin Resistance in Isolated Impaired Fasting Glucose and Isolated Impaired Glucose Tolerance.
abstract: OBJECTIVE
  To investigate the characteristics of isolated impaired glucose tolerance (IGT) and isolated impaired fasting glucose (IFG), we analyzed the factors responsible for elevation of 2-hour postchallenge plasma glucose (2 h PG) and fasting plasma glucose (FPG) levels.
  
  
  METHODS
  We investigated the relationship between 2 h PG and FPG levels who underwent 75 g OGTT in 5620 Japanese subjects at initial examination for medical check-up. We compared clinical characteristics between isolated IGT and isolated IFG and analyzed the relationships of 2 h PG and FPG with clinical characteristics, the indices of insulin secretory capacity, and insulin sensitivity.
  
  
  RESULTS
  In a comparison between isolated IGT and isolated IFG, insulinogenic index was lower in isolated IGT than that of isolated IFG (0.43 ± 0.34 versus 0.50 ± 0.47, resp.; p < 0.01). ISI composite was lower in isolated IFG than that of isolated IGT (6.87 ± 3.38 versus 7.98 ± 4.03, resp.; p < 0.0001). In isolated IGT group, insulinogenic index showed a significant correlation with 2 h PG (r = -0.245, p < 0.0001) and had the strongest correlation with 2 h PG (β = -0.290). In isolated IFG group, ISI composite showed a significant correlation with FPG (r = -0.162, p < 0.0001) and had the strongest correlation with FPG (β = -0.214).
  
  
  CONCLUSIONS
  We have elucidated that decreased early-phase insulin secretion is the most important factor responsible for elevation of 2 h PG levels in isolated IGT subjects, and decreased insulin sensitivity is the most important factor responsible for elevation of FPG levels in isolated IFG subjects.
authors.affiliation: Division of Clinical Nutrition and Internal Medicine, Okayama Prefectural University, Okayama 719-1197, Japan.
authors.forename: Sae
authors.initials: S
authors.lastname: Aoyama-Sasabe
authors.affiliation: Division of Clinical Nutrition and Internal Medicine, Okayama Prefectural University, Okayama 719-1197, Japan; Preemptive Medicine and Lifestyle-Related Disease Research Center, Kyoto University Hospital, Kyoto 606-8507, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Fukushima
authors.affiliation: Faculty of Computer Science and Systems Engineering, Okayama Prefectural University, Okayama 719-1197, Japan.
authors.forename: Xin
authors.initials: X
authors.lastname: Xin
authors.affiliation: Division of Diabetes and Endocrinology, Kyoto Preventive Medical Center, Kyoto 604-8491, Japan.
authors.forename: Ataru
authors.initials: A
authors.lastname: Taniguchi
authors.affiliation: Kyoto Institute of Health Science, Kyoto 604-0845, Japan.
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Nakai
authors.affiliation: Center for Preventive Medicine, St. Luke's International Hospital, Tokyo 104-6591, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Mitsui
authors.affiliation: Faculty of Health and Welfare Science, Okayama Prefectural University, Okayama 719-1197, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Faculty of Health and Welfare Science, Okayama Prefectural University, Okayama 719-1197, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tsuji
authors.affiliation: Center for Diabetes, Endocrinology and Metabolism, Kansai Electric Power Hospital, Osaka 553-0003, Japan; Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe 650-0047, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yabe
authors.affiliation: Department of Diabetes and Endocrinology, Saiseikai Noe Hospital, Osaka 536-0001, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yasuda
authors.affiliation: Center for Diabetes, Endocrinology and Metabolism, Kansai Electric Power Hospital, Osaka 553-0003, Japan; Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe 650-0047, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kurose
authors.affiliation: Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Nobuya
authors.initials: N
authors.lastname: Inagaki
authors.affiliation: Center for Diabetes, Endocrinology and Metabolism, Kansai Electric Power Hospital, Osaka 553-0003, Japan; Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe 650-0047, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Seino
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005215:Fasting / Q000097:blood*; D005260:Female; D018149:Glucose Intolerance / Q000097:blood* / Q000175:diagnosis; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007564:Japan; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin