title: Intravenous glucose tolerance test-derived glucose effectiveness in physically trained humans.
abstract: Glucose effectiveness (SG) and insulin sensitivity of sedentary and physically trained males were estimated by the minimal model approach. Trained subjects, who ran 86 +/- 10 km/wk and had 37% higher maximal oxygen consumption than that of sedentary subjects (56.2 +/- 1.2 vs. 40.9 +/- 1.4 ml.kg-1 x min-1, P < 0.01), were studied 16 h and 1 wk after their last training session. After overnight fasting, glucose was administered intravenously (300 mg/kg body wt) within 2 min, and insulin was infused (approximately 13-20 mU/kg given over 5 min) from 20 to 25 min after administration of glucose. Glucose disappearance constant values as an estimate of glucose tolerance were significantly higher in trained subjects after 16 h and 1 wk of their training session (3.29 +/- 0.48 and 3.60 +/- 0.64%/min) than in sedentary subjects (1.92 +/- 0.30%/min, P < 0.05). Insulin sensitivity in trained subjects measured after 16 h and 1 wk of their last training session (26.2 +/- 4.4 and 24.3 +/- 6.0 x 10(-5) min-1 x pM-1) was also higher than that of sedentary subjects (10.3 +/- 1.2 x 10(-5) min-1 x pM-1, P < 0.05). SG, the ability of glucose itself to increase peripheral glucose uptake and suppress hepatic glucose output, was significantly higher in trained subjects after 16 h and 1 wk of their last training session (0.028 +/- 0.003 and 0.030 +/- 0.004/min) than in sedentary subjects (0.017 +/- 0.002/min, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratory of Biochemistry of Exercise and Nutrition, University of Tsukuba, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tokuyama
authors.forename: Y
authors.initials: Y
authors.lastname: Higaki
authors.forename: J
authors.initials: J
authors.lastname: Fujitani
authors.forename: A
authors.initials: A
authors.lastname: Kiyonaga
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Shindo
authors.forename: M
authors.initials: M
authors.lastname: Fukushima
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
authors.forename: H
authors.initials: H
authors.lastname: Imura
authors.forename: I
authors.initials: I
authors.lastname: Nagata
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D005947:Glucose / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006801:Humans; D007275:Injections, Intravenous; D007328:Insulin / Q000097:blood; D008297:Male; D009994:Osmolar Concentration; D010806:Physical Education and Training; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose