title: Relationship of insulin resistance to macro- and microvasculature reactivity in hypertension.
abstract: BACKGROUND
  Although insulin resistance (IR) is thought to be related to vascular dysfunction, the difference in the relationship of IR to microvasculature and macrovasculature reactivity has not yet been clarified. The present study was conducted to clarify whether the IR is more closely related to the macrovasculature reactivity (flow-mediated vasodilatation of the brachial artery induced by reactive hyperemia: FMD) or microvasculature reactivity (skin reactive hyperemia as assessed by laser Doppler flowmetry: SRH) in patients with hypertension.
  
  
  METHODS
  In 75 consecutive hypertensive patients (61 +/- 11 years of age) without obvious cardiovascular (CV) disease and/or risk factors for CV disease other than hypertension, FMD, SRH, and homeostasis model assessment index of IR (HOMA(IR)) were measured.
  
  
  RESULTS
  No significant relationship was observed between FMD with the parameters of SRH. In the univariate linear regression analysis, HOMA(IR) showed a significant correlation with the FMD (R(2) = 0.05, P < 0.05), but not with the parameters of SRH. Multivariate linear regression analysis demonstrated a significant association between HOMA(IR) and FMD, even after adjustments for covariates, including the use of medication for hypertension. (R(2) = 0.32, beta = -0.29, P = 0.02).
  
  
  CONCLUSIONS
  The complication of IR in hypertensive patients without obvious CV disease/risk factors may be related to impaired macrovasculature rather than microvasculature reactivity, apart from the influence of antihypertensive medication on the reactivity of the vasculature and insulin sensitivity.
authors.affiliation: Second Department of Internal Medicine, Tokyo Medical University, Tokyo, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yoshida
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tomiyama
authors.forename: Jiko
authors.initials: J
authors.lastname: Yamada
authors.forename: Chisa
authors.initials: C
authors.lastname: Matsumoto
authors.forename: Mari
authors.initials: M
authors.lastname: Odaira
authors.forename: Kazuki
authors.initials: K
authors.lastname: Shiina
authors.forename: Akira
authors.initials: A
authors.lastname: Yamashina
mesh_terms: D000368:Aged; D001775:Blood Circulation / Q000502:physiology; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D006973:Hypertension / Q000503:physiopathology*; D007333:Insulin Resistance / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D009569:Nitric Oxide / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D012189:Retrospective Studies; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology
chemical_list: D009569:Nitric Oxide