title: Brachial artery pulsatility index change 1 minute after 5-minute forearm compression: comparison with flow-mediated dilatation.
abstract: OBJECTIVE
  Endothelial impairment evaluation by sonographic measurement of flow-mediated dilatation (FMD) has become broadly used. However, this method has 2 main caveats: the dilatation depends on the baseline arterial diameter, and a high precision level is required. Vasodilatation leads to an amplified fall in impedance. We hypothesized that assessment of the pulsatility index change (PI-C) 1 minute after 5-minute forearm compression might evaluate that fall in impedance. The aim of this study was to compare the PI-C with FMD.
  
  
  METHODS
  Flow-mediated dilatation and the PI-C were assessed in 51 healthy women aged between 35.1 and 67.1 years. We correlated both FMD and the PI-C with age, body mass index, waist circumference, cholesterol level, high-density lipoprotein level, glucose level, systolic and diastolic blood pressure, pulse pressure, brachial artery diameter, simplified Framingham score, intima-media thickness, and carotid stiffness index. Intraclass correlation coefficients between 2 FMD and PI-C measurements were also examined.
  
  
  RESULTS
  Only FMD correlated with baseline brachial diameter (r = -0.53). The PI-C had a high correlation with age, body mass index, waist circumference, cholesterol level, systolic blood pressure, pulse pressure, simplified Framingham score, and intima-media thickness. The correlation between FMD and the PI-C was high (r = -0.66). The PI-C had a higher intraclass correlation coefficient (0.991) than FMD (0.836) but not brachial artery diameter (0.989).
  
  
  CONCLUSIONS
  The PI-C had a large correlation with various markers of cardiovascular risk. Additionally, PI-C measurement does not require offline analysis, extra software, or electrocardiography. We think that the PI-C could be considered a marker of endothelial function. However, more studies are required before further conclusions.
authors.affiliation: Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14049-900 São Paulo-SP, Brazil. wpmartins@gmail.com
authors.forename: Wellington P
authors.initials: WP
authors.lastname: Martins
authors.forename: Carolina O
authors.initials: CO
authors.lastname: Nastri
authors.forename: Rui A
authors.initials: RA
authors.lastname: Ferriani
authors.forename: Francisco Mauad
authors.initials: FM
authors.lastname: Filho
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D001837:Body Weights and Measures; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D003327:Coronary Disease / Q000145:classification; D004548:Elasticity; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D013997:Time Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000502:physiology; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000502:physiology; D018617:Ultrasonography, Doppler, Pulsed; D014655:Vascular Resistance / Q000502:physiology; D014664:Vasodilation / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D002784:Cholesterol