title: Insulin's microvascular vasodilatory effects are inversely related to peripheral vascular resistance in overweight, but insulin-sensitive subjects.
abstract: OBJECTIVE
  The mechanisms underlying obesity-related hypertension are incompletely understood. Microvascular dysfunction might play a role by increasing peripheral vascular resistance (PVR). Metabolic and microvascular effects of insulin are impaired in obesity, but how these impairments contribute to disturbed blood pressure homeostasis is unclear. Specifically, it is unknown whether local microvascular vasoactive effects of insulin play a role in determining systemic vascular resistance. The aim of this study was to investigate the association between PVR and local microvascular effects of insulin.
  
  
  METHODS
  Thirty-seven healthy, overweight subjects (age 25-55 years, BMI 25-30 kg/m(2) ) were cross-sectionally studied. Local insulin-mediated vasodilation was measured using skin laser Doppler fluxmetry combined with transcutaneous iontophoresis of insulin. For comparison, local vasodilatory effects of acetylcholine and sodium nitroprusside were measured. PVR was calculated from mean arterial pressure and cardiac output, assessed by pulse-dye densitometry.
  
  
  RESULTS
  PVR was inversely correlated with insulin-mediated vasodilation (r = -0.50; P < 0.01). This finding was maintained after adjustment for age, sex, blood pressure, and smoking. PVR was not associated with local microvascular effects of acetylcholine.
  
  
  CONCLUSIONS
  Our study in overweight subjects suggests that insulin's role in the microvasculature may contribute to blood pressure control.
authors.affiliation: Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands; Institute for Cardiovascular Research of the VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Hornstra
authors.forename: E H
authors.initials: EH
authors.lastname: Serné
authors.forename: E C
authors.initials: EC
authors.lastname: Eringa
authors.forename: M C
authors.initials: MC
authors.lastname: Wijnker
authors.forename: M P
authors.initials: MP
authors.lastname: de Boer
authors.forename: J S
authors.initials: JS
authors.lastname: Yudkin
authors.forename: Y M
authors.initials: YM
authors.lastname: Smulders
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance / Q000502:physiology*; D007478:Iontophoresis; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D050177:Overweight / Q000503:physiopathology*; D014655:Vascular Resistance / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D007328:Insulin; D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine