title: Effect of dexamethasone on insulin sensitivity, islet amyloid polypeptide and insulin secretion in humans.
abstract: The response of islet amyloid polypeptide and insulin and their molar ratios were investigated in eight healthy volunteers before and after treatment with dexamethasone by oral and frequently-sampled intravenous glucose tolerance tests. Following dexamethasone treatment the insulin sensitivity index decreased significantly from 6.5 +/- 1.3 to 4.1 +/- 1.0 (microU.ml-1).min-1, p < 0.05. The area under the curve representing above-basal levels of insulin during oral glucose tolerance test increased significantly following dexamethasone treatment from 48132 +/- 9736 to 82230 +/- 14846 pmol.l-1 x 3 h-1, p < 0.05, the area under the curve of islet amyloid polypeptide increased from 1308 +/- 183 to 2448 +/- 501 pmol.l-1 x 3 h-1, p < 0.05. The overall insulin/islet amyloid polypeptide molar ratios calculated from the area under the curve during the 3-h period of the oral glucose tolerance test was not significantly different before and after dexamethasone treatment (42 +/- 5 vs 40 +/- 4). During the oral glucose tolerance test the insulin/islet amyloid polypeptide ratio increased significantly from baseline to 30 min (p < 0.05), then declined towards initial values before and after dexamethasone treatment. In conclusion, dexamethasone induced a significant decrease in insulin sensitivity and a significant increase in insulin secretion during the oral glucose tolerance test. However, in contrast to previous animal experiments we did not find a change in the insulin/islet amyloid polypeptide ratio before and after dexamethasone treatment.
authors.affiliation: Department of Medicine III, University of Vienna, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Ludvik
authors.forename: M
authors.initials: M
authors.lastname: Clodi
authors.forename: A
authors.initials: A
authors.lastname: Kautzky-Willer
authors.forename: M
authors.initials: M
authors.lastname: Capek
authors.forename: E
authors.initials: E
authors.lastname: Hartter
authors.forename: G
authors.initials: G
authors.lastname: Pacini
authors.forename: R
authors.initials: R
authors.lastname: Prager
mesh_terms: D000328:Adult; D000682:Amyloid / Q000097:blood / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism* / Q000502:physiology; D000078790:Insulin Secretion; D058228:Islet Amyloid Polypeptide; D007700:Kinetics; D008297:Male; D012016:Reference Values; D013997:Time Factors
chemical_list: D000682:Amyloid; D001786:Blood Glucose; D007328:Insulin; D058228:Islet Amyloid Polypeptide; D003907:Dexamethasone