title: Assessment of red blood cell glutathione status in insulin resistance.
abstract: The aim of this study was to assess red blood cell glutathione from insulin-sensitive and insulin-resistant individuals before and after an oral glucose dose. Fifteen healthy, young (24 ± 5 years), nonobese (23 ± 2 kg·m⁻²), insulin-sensitive (ISI composite = 6.0 ± 1.2) individuals and 14 healthy, young (22 ± 2 years), nonobese (24 ± 2 kg·m⁻²), insulin-resistant (ISI composite = 2.7 ± 1.1) individuals received a 75 g oral glucose dose. Blood samples were drawn before and for 2 h after glucose ingestion for red blood cell glutathione and serum glucose and insulin concentrations. Glycemia before and after glucose ingestion was similar between groups (p = 0.17), which suggest that hyperinsulinemia compensated impaired insulin sensitivity. Red blood cell total (p = 0.81), reduced (p = 0.79), and oxidized (p = 0.88) glutathione concentrations were similar between groups under fasting and postprandial conditions. However, in response to glucose, increases in total and reduced glutathione concentrations were found at the end of the 2 h assessment period in both groups (p < 0.05). Direct associations between postprandial glucose response and red blood cell total (r = 0.52; p < 0.05) and oxidized (r = 0.61; p = 0.02) glutathione concentrations were observed only in insulin-sensitive subjects. In conclusion, healthy individuals differing in their degree of insulin resistance showed similar red blood cell glutathione concentrations under non-glucose- and glucose-stimulated conditions.
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile. jgalgani@med.uchile.cl
authors.forename: Jose E
authors.initials: JE
authors.lastname: Galgani
authors.forename: Karla
authors.initials: K
authors.lastname: Vasquez
authors.forename: Giannella
authors.initials: G
authors.lastname: Leonelli
authors.forename: Alejandra
authors.initials: A
authors.lastname: Espinosa
authors.forename: Hector
authors.initials: H
authors.lastname: Araya
authors.forename: Francisco
authors.initials: F
authors.lastname: Perez-Bravo
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D005978:Glutathione / Q000097:blood* / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000503:physiopathology; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D010084:Oxidation-Reduction; D019518:Postprandial Period; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005978:Glutathione