title: Incretin responses to oral glucose load in Japanese non-obese healthy subjects.
abstract: BACKGROUND
  Recently, incretin-related therapy has been developed for the new treatment of diabetes mellitus; however, incretin response to glucose ingestion in normal glucose tolerant (NGT) subjects has not been clarified in detail with special reference to the role of incretin hormones, glucagon, and a family history of diabetes.
  
  
  METHODS
  We conducted a 75 g oral glucose tolerance test in 30 NGT subjects.
  
  
  RESULTS
  The total glucose-dependent insulinotropic peptide (GIP)-AUC(0-120) (area under the curve over a period of 0-120 minutes) was correlated with immunoreactive insulin (IRI)-AUC(0-120) (P<0.05), insulinogenic index (II; P<0.05), ΔIRI between 0 and 120 minutes (P<0.05). Active glucagon-like peptide-1 (GLP-1) AUC(0-120) was correlated inversely both with Δ glucose between 0 and 30 minutes (P<0.01) and with Δ immunoreactive glucagon between 0 and 30 minutes (P<0.05). Δ Total GIP between 0 and 15 minutes (P<0.01), Δ total GIP between 0 and 30 minutes (P<0.05), and the total GIP-AUC(0-120) (P<0.05) in the subjects with a family history of type 2 diabetes were significantly higher than those in the subjects without a family history.
  
  
  CONCLUSIONS
  These results suggest that GIP possibly facilitates insulin secretion in response to oral glucose load directly and active GLP-1 may exert the glucoregulatory action via the suppression of glucagon secretion in NGT subjects. Notably, the subjects with a family history of diabetes exert significantly higher GIP response in the early phase of glucose load compared with those without a family history.
authors: Division of Diabetes and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan, e-nagai@hyo-med.ac.jp.
authors: Etsuko
authors: E
authors: Nagai
authors: Tomoyuki
authors: T
authors: Katsuno
authors: Jun-Ichiro
authors: J
authors: Miyagawa
authors: Kosuke
authors: K
authors: Konishi
authors: Masayuki
authors: M
authors: Miuchi
authors: Fumihiro
authors: F
authors: Ochi
authors: Yoshiki
authors: Y
authors: Kusunoki
authors: Masaru
authors: M
authors: Tokuda
authors: Kazuki
authors: K
authors: Murai
authors: Tomoya
authors: T
authors: Hamaguchi
authors: Mitsuyoshi
authors: M
authors: Namba