title: Vascular endothelial function and blood pressure regulation in afferent autonomic failure.
abstract: BACKGROUND
  Familial dysautonomia (FD) is a rare hereditary disease characterized by loss of afferent autonomic neural fiber signaling and consequent profound impairment of arterial baroreflex function and blood pressure regulation. Whether vascular endothelial dysfunction contributes to defective vasomotor control in this form of afferent autonomic failure is not known.
  
  
  METHODS
  We assessed blood pressure response to orthostatic stress and vascular endothelial function with brachial artery reactivity testing in 34 FD subjects with afferent autonomic failure and 34 healthy control subjects.
  
  
  RESULTS
  Forty-four percent of the afferent autonomic failure subjects had uncontrolled hypertension at supine rest (median systolic blood pressure = 148mm Hg, interquartile range (IQR) = 144-155mm Hg; median diastolic blood pressure = 83mm Hg, IQR = 78-105mm Hg), and 88% had abnormal response to orthostatic stress (median decrease in systolic blood pressure after upright tilt = 48mm Hg, IQR = 29-61mm Hg). Flow-mediated brachial artery reactivity did not differ in subjects with afferent autonomic failure vs. healthy control subjects (median = 6.00%, IQR = 1.86-11.77%; vs. median = 6.27%, IQR = 4.65-9.34%; P = 0.75). In afferent autonomic failure subjects, brachial artery reactivity was not associated with resting blood pressure or the magnitude of orthostatic hypotension but was decreased in association with reduced glomerular filtration rate (r = 0.62; P < 0.001).
  
  
  CONCLUSIONS
  Brachial artery reactivity was preserved in subjects with afferent autonomic failure despite the presence of marked blood pressure dysregulation. Comorbid renal dysfunction was associated with reduced brachial artery reactivity.
authors.affiliation: Leon H. Charney Division of Cardiology, New York University School of Medicine, New York University Langone Medical Center, New York, New York;
authors.forename: Qurat-Ul-Ain
authors.initials: QU
authors.lastname: Jelani
authors.affiliation: Dysautonomia Center, New York University School of Medicine, New York University Langone Medical Center, New York, New York.
authors.forename: Lucy
authors.initials: L
authors.lastname: Norcliffe-Kaufmann
authors.affiliation: Dysautonomia Center, New York University School of Medicine, New York University Langone Medical Center, New York, New York.
authors.forename: Horacio
authors.initials: H
authors.lastname: Kaufmann
authors.affiliation: Leon H. Charney Division of Cardiology, New York University School of Medicine, New York University Langone Medical Center, New York, New York; stuart.katz@nyumc.org.
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Katz
mesh_terms: D000293:Adolescent; D000328:Adult; D000344:Afferent Pathways; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D004402:Dysautonomia, Familial / Q000150:complications / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D007024:Hypotension, Orthostatic / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D014463:Ultrasonography; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology; D055815:Young Adult
keywords: autonomic failure; autonomic function; blood pressure; brachial reactivity; endothelial function; hypertension; labile hypertension; orthostatic hypotension