title: Insulin resistance and beat-to-beat cardiovascular dynamics: a constant relationship across different body mass index and blood pressure categories.
abstract: BACKGROUND
  Epidemiological studies have shown a progressive increase in insulin resistance (IR) accompanying body weight gain and blood pressure (BP) increase. This has led to the consideration that hemodynamic effects of IR might depend on its relationship with body mass index (BMI) and BP.
  
  
  OBJECTIVE
  The aim of our study was to determine whether IR is associated with changes in hemodynamic indices of cardiovascular function across different categories of BMI (normal weight, overweight, and obese), and BP levels (normal, high normal, and hypertension).
  
  
  METHODS
  This was a cross-sectional study conducted in a population sample of nondiabetic individuals (n = 731).
  
  
  METHODS
  Insulin resistance was evaluated with the homeostasis model assessment of insulin resistance (HOMA) and subjects were classified into quartiles according to HOMA index values. Synchronized beat-to-beat recordings of stroke volume (impedance cardiography) and R-R interval, along with repeated auscultatory BP measurements were performed. Derived hemodynamic parameters were computed and averaged.
  
  
  RESULTS
  Analysis of covariance adjusting for confounders showed significant differences for most hemodynamic parameters among different quartiles of HOMA index both in the general population and within each BMI and BP category. Overall, increasing values of HOMA index were associated with significantly higher BP; and reduced R-R interval, stroke index, cardiac index, pre-ejection period and left ventricular ejection time (P < .01) across different categories of BMI and BP.
  
  
  CONCLUSIONS
  These findings suggest that even small increases in HOMA index (not necessarily in the range to define IR) may induce significant changes on indices of cardiovascular function even in normal-weight and normotensive subjects, emphasizing the importance of IR at an early stage of the cardiovascular risk continuum.
authors.affiliation: Department of Health Sciences (J.E.O., G.P.), University of Milan-Bicocca, 20126 Milan, Italy; Department of Cellular and Molecular Biology (J.E.O., J.G.M.), Corporación para Investigaciones Biológicas, Medellín, Colombia; Clinical and Research Center (J.A.G., M.M.C., D.A.), SICOR, Medellín, Colombia; School of Medicine and Nursing (J.A.G., N.Z., J.G.M.), Universidad de Antioquia, Medellín, Colombia; and Department of Cardiology (G.B., G.P.), San Luca Hospital, IRCCS Istituto Auxologico Italiano, 20149 Milan, Italy.
authors.forename: Juan Eugenio
authors.initials: JE
authors.lastname: Ochoa
authors.forename: Jaime Alberto
authors.initials: JA
authors.lastname: Gallo
authors.forename: Mónica Maria
authors.initials: MM
authors.lastname: Correa
authors.forename: Nora
authors.initials: N
authors.lastname: Zapata
authors.forename: Juan Guillermo
authors.initials: JG
authors.lastname: McEwen
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bilo
authors.forename: Dagnovar
authors.initials: D
authors.lastname: Aristizabal
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D050177:Overweight / Q000150:complications / Q000503:physiopathology*