title: Nitroglycerin-mediated, but not flow-mediated vasodilation, is associated with blunted nocturnal blood pressure fall in patients with resistant hypertension.
abstract: BACKGROUND
  Endothelial function by flow-mediated (FMD) and nitroglycerin-mediated vasodilations (NMD) was scarcely investigated in resistant hypertension. We aimed to assess the independent correlates of FMD and NMD in resistant hypertensive patients, particularly their associations with ambulatory blood pressures (BP) and nocturnal BP fall patterns.
  
  
  METHODS
  In a cross-sectional study, 280 resistant hypertensive patients performed 24-h ambulatory BP monitoring, carotid-femoral pulse wave velocity, polysomnography, and brachial artery FMD and NMD by high-resolution ultrasonography. Independent correlates of FMD, NMD, and brachial artery diameter (BAD) were assessed by multiple linear and logistic regressions.
  
  
  RESULTS
  Median (interquartile range) FMD was 0.75% (-0.6 to +4.4%) and NMD was 11.8% (7.1-18.4%). Baseline BAD and diabetes were independently associated with both FMD and NMD. Older age and prior cardiovascular diseases were associated with altered FMD, whereas higher night-time SBP and lower nocturnal SBP fall were associated with impaired NMD. Moreover, there was a significant gradient of impaired NMD according to blunted nocturnal BP decline patterns. BAD was independently associated with age, sex, BMI, albuminuria, and nocturnal SBP fall. Further adjustments to blood flow velocity, aortic stiffness, plasma aldosterone concentration, and sleep apnea did not change these relationships.
  
  
  CONCLUSIONS
  NMD, but not FMD, is independently associated with unfavorable night-time BP levels and nondipping patterns, and may be a better cardiovascular risk marker in patients with resistant hypertension. BAD also may provide additional prognostic information.
authors.affiliation: Department of Internal Medicine, University Hospital Clementino Fraga Filho, School of Medicine, Universidade Federal do Rio de Janeiro, Brasil.
authors.forename: Priscila C A
authors.initials: PC
authors.lastname: Fontes-Guerra
authors.forename: Claudia R L
authors.initials: CR
authors.lastname: Cardoso
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Muxfeldt
authors.forename: Gil F
authors.initials: GF
authors.lastname: Salles
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000494:pharmacology*; D017286:Polysomnography; D063177:Pulse Wave Analysis; D012039:Regional Blood Flow; D012307:Risk Factors; D013997:Time Factors; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin