title: Troglitazone-induced changes in adiponectin do not affect endothelial function in diabetes.
abstract: OBJECTIVE
  Adiponectin has been proposed to be related to endothelial function. We have examined the relationship between the increase in adiponectin levels that is associated with troglitazone treatment and endothelium-dependent vasodilation in type 2 diabetic patients.
  
  
  METHODS
  Seventy-two patients participated in this randomized, placebo-controlled, double-blinded study. High-resolution ultrasound images were used to measure the flow-mediated dilation (endothelium-dependent) and nitroglycerin-induced dilation (endothelium-independent) of the brachial artery. Laser Doppler perfusion imaging was employed to measure the vascular reactivity in the forearm skin.
  
  
  RESULTS
  Troglitazone treatment resulted in an average 75% increase in the adiponectin levels, but no changes were observed in the endothelium-dependent vasodilation, any other measurement of vascular reactivity, or any other markers of endothelial activation. Also, no changes were observed in the expression of the receptor for advanced glycation end-products in skin biopsies taken from the forearm. Significant correlations were observed during troglitazone treatment between the changes in the adiponectin levels and the changes in fasting plasma glucose (r = -0.29, p < 0.05), hemoglobin A(1c) (r = -0.30, p < 0.05), total cholesterol (r = 0.25, p < 0.05), and low-density lipoprotein-cholesterol (r = 0.34, p < 0.01).
  
  
  CONCLUSIONS
  The increase in adiponectin levels after troglitazone treatment is not associated with an improvement in the endothelium-dependent vasodilation, indicating that adiponectin is not a major determinant of endothelial function. In addition, receptor for advanced glycation end-products expression in the skin microcirculation is not affected by troglitazone treatment.
authors.affiliation: Microcirculation Laboratory, Palmer 317, West Campus, Beth Israel Deaconess Medical Center, One Deaconess Road, Boston, MA 02215, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Buras
authors.forename: Wende R
authors.initials: WR
authors.lastname: Reenstra
authors.forename: Daniel
authors.initials: D
authors.lastname: Orlow
authors.forename: Edward S
authors.initials: ES
authors.lastname: Horton
authors.forename: Aristidis
authors.initials: A
authors.lastname: Veves
mesh_terms: D052242:Adiponectin / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001916:Brachial Artery; D002839:Chromans / Q000494:pharmacology* / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000517:prevention & control; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D045162:Thiazolidinediones / Q000494:pharmacology* / Q000627:therapeutic use; D000077288:Troglitazone; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
chemical_list: D052242:Adiponectin; D002839:Chromans; D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000077288:Troglitazone