title: Dynamics of insulin action in hypertension: assessment from minimal model interpretation of intravenous glucose tolerance test data.
abstract: Based on glucose kinetics minimal model (GKMM) interpretation of frequently sampled intravenous glucose tolerance test (FSIGTT), the aim was to broaden the characterization of insulin-mediated glucose disposal in hypertension by aid of a dynamic insulin sensitivity index, S(D)(I), and the related efficiency, η = S(D)(I) / S(I), of the metabolic system to convert the maximal individual response capacity, measured by S (I), into an effective insulin control on glucose. The C-peptide minimal model (CPMM) was used to interpret the role of β-cell function. Plasma glucose, insulin, and C-peptide concentrations were measured, during a 5-h FSIGTT, in eighteen normoglycemic individuals: ten hypertensive patients (H-group) and eight normotensive subjects (N-group) with no metabolic syndrome. Compared to our N-group, the H-group showed a significant (P < 0.05) reduction of both S(I) (56%) and S(D)(I) (50%), no significant change of η, a significant increase of both the first-phase β-cell responsiveness to glucose (105%) and total insulin secretion (55%), and no significant change in disposition indexes, defined as the product of insulin sensitivity (either S(I) and S(D)(I)) and β-cell responsiveness. These findings suggest that, in spite of no change of efficiency, insulin resistance in normoglycemic hypertensive patients is primarily compensated by an increase in first-phase insulin secretion to preserve glucose tolerance to intravenous glucose load.
authors: Department of Biomedical, Electronics and Telecommunication Engineering, Polytechnic University of Marche, 60131 Ancona, Italy. r.burattini@univpm.it
authors: Roberto
authors: R
authors: Burattini
authors: Micaela
authors: M
authors: Morettini
authors: Francesco
authors: F
authors: Di Nardo
authors: Massimo
authors: M
authors: Boemi
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods; D006801:Humans; D006973:Hypertension / Q000097:blood*; D007004:Hypoglycemic Agents / Q000097:blood*; D007328:Insulin / Q000097:blood*; D050417:Insulin-Secreting Cells / Q000502:physiology; D008297:Male; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007004:Hypoglycemic Agents; D007328:Insulin