title: The impairment of flow-mediated vasodilatation in obese men with visceral fat accumulation.
abstract: BACKGROUND
  Obesity has been reported to be associated with coronary artery disease and other atherosclerotic diseases. Recently, evidence has accumulated indicating that intra-abdominal visceral fat accumulation contributes to atherogenesis; however, the mechanism underlying this remains to be determined. This study was undertaken to elucidate whether intra-abdominal visceral fat accumulation impairs vascular endothelial function in obese men.
  
  
  RESULTS
  Thirty-eight obese men (body mass index (BMI) > or = 26.0), aged 19-64 y (mean age 37.6 +/- 1.8 y) and 23 age-matched non-obese subjects were examined. According to the ratio of the maximum thickness of preperitoneal fat to the minimum thickness of subcutaneous fat (Pmax/Smin) obtained by longitudinal ultrasound scanning in the subxiphoid region in obese men, we divided obese subjects into two categories; visceral (Pmax/Smin > or = 1; n=23) and subcutaneous type (Pmax/Smin < 1; n=15). To investigate endothelial function, we performed ultrasound measurement of the brachial artery diameter non-invasively both at rest and during reactive hyperaemia in the muscle distal to the brachial artery which causes endothelium-dependent vasodilatation. The brachial diameter change was also measured after sublingual administration of nitroglycerin, which causes endothelium-independent vasodilatation. Flow-mediated diameter (D) increase (%FMD; deltaD/D x 100), in the subjects with visceral type obesity (3.09 +/- 0.43%) was significantly lower than those of the subjects with subcutaneous type obesity and non-obese subjects (7.90 +/- 0.51%, 8.91 +/- 0.44%, respectively, P < 0.01). The magnitude of endothelium-independent vasodilatation by nitroglycerin was similar in all groups. On multiple regression analysis, the Pmax/Smin showed a significant inverse correlation with %FMD.
  
  
  CONCLUSIONS
  The subjects with visceral type obesity, rather than those with the subcutaneous type, are associated with impaired flow-mediated endothelium-dependent vasodilatation of the brachial artery.
authors.affiliation: Department of Geriatrics, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hashimoto
authors.forename: M
authors.initials: M
authors.lastname: Akishita
authors.forename: M
authors.initials: M
authors.lastname: Eto
authors.forename: K
authors.initials: K
authors.lastname: Kozaki
authors.forename: J
authors.initials: J
authors.lastname: Ako
authors.forename: N
authors.initials: N
authors.lastname: Sugimoto
authors.forename: M
authors.initials: M
authors.lastname: Yoshizumi
authors.forename: K
authors.initials: K
authors.lastname: Toba
authors.forename: Y
authors.initials: Y
authors.lastname: Ouchi
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D001783:Blood Flow Velocity; D001824:Body Constitution; D015992:Body Mass Index; D001916:Brachial Artery / Q000503:physiopathology; D002784:Cholesterol / Q000097:blood; D004730:Endothelium, Vascular / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000494:pharmacology; D009765:Obesity / Q000503:physiopathology*; D012044:Regression Analysis; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000187:drug effects
chemical_list: D014280:Triglycerides; D002784:Cholesterol; D005996:Nitroglycerin