title: Impaired hemodynamic response to meal intake in insulin-resistant subjects: an impedance cardiography approach.
abstract: BACKGROUND
  In the postprandial state, insulin regulates metabolic and cardiovascular responses. In insulin resistance, the insulin action is impaired at both levels. However, postprandial hemodynamic responses are poorly characterized in this setting.
  
  
  OBJECTIVE
  We investigated fasting and postprandial cardiac and vascular hemodynamic responses in subjects with and without insulin resistance.
  
  
  METHODS
  Sixty-six atherosclerosis-free, healthy volunteers were studied in a fasted state and ≤180 min after ingestion of a mixed meal. The insulin sensitivity index was determined by using a minimal model analysis; hemodynamic response was monitored by using continuous impedance cardiography that allowed a reliable beat-to-beat noninvasive evaluation of stroke volume, cardiac contractility, and several derived variables.
  
  
  RESULTS
  Subjects were divided into insulin-resistant (IR; n = 33) and insulin-sensitive (IS; n = 33) groups. After fasting, IR subjects had significantly higher values of systolic and diastolic blood pressures and the systemic vascular resistance index (SVRI) than did IS subjects. In the postprandial state, acute vasodilatation was comparable and synchronous (at 30 min) in IR and IS subjects (P = 0.209), but subsequent vascular tone recovery (30-180 min) was significantly impaired in IR subjects (P = 0.018), even after adjustment for age and sex (P = 0.031). Hemodynamic dysregulation was directly correlated with metabolic disturbances in the postprandial state. In basal and postprandial states, hemodynamic variables related to cardiac function were not significantly different in IR and IS subjects.
  
  
  CONCLUSIONS
  IR subjects had a worse fasting vascular performance than did IS subjects. In the postprandial phase, insulin resistance was associated with a shorter duration of vasodilatation in the absence of an altered cardiac performance. Peripheral hemodynamic alterations in fasting and postprandial states may have a negative effect on cardiovascular performance in IR patients.
authors.affiliation: Departments of Clinical and Experimental Medicine and Information Engineering, Padova University, Padova, Italy. saula.dekreutzenberg@unipd.it
authors.forename: Saula
authors.initials: S
authors.lastname: Vigili de Kreutzenberg
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Fadini
authors.forename: Federico
authors.initials: F
authors.lastname: Boscari
authors.forename: Elisa
authors.initials: E
authors.lastname: Rossi
authors.forename: Stefania
authors.initials: S
authors.lastname: Guerra
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sparacino
authors.forename: Claudio
authors.initials: C
authors.lastname: Cobelli
authors.forename: Giulio
authors.initials: G
authors.lastname: Ceolotto
authors.forename: Matteo
authors.initials: M
authors.lastname: Bottero
authors.forename: Angelo
authors.initials: A
authors.lastname: Avogaro
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D002096:C-Peptide / Q000097:blood; D002307:Cardiography, Impedance; D002318:Cardiovascular Diseases / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004435:Eating; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D014655:Vascular Resistance; D014664:Vasodilation
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin