title: High serum leptin is associated with attenuated coronary vasoreactivity.
abstract: OBJECTIVE
  Hyperleptinemia, a hallmark of obesity, appears to be a risk factor for coronary artery disease. However, although leptin is a vasoactive hormone, no studies addressing leptin's effect on coronary perfusion have been performed. We examined the association between circulating leptin concentration and coronary vasoreactivity in young obese and nonobese males.
  
  
  METHODS
  Myocardial blood flow was quantitated in 10 obese men (age 31 +/- 7 years, BMI 34 +/- 2 kg/m(2)) and 10 healthy matched nonobese men (age 33 +/- 8 years, BMI 24 +/- 2 kg/m(2)) using positron emission tomography and O-15-water. The measurements were performed basally and during adenosine infusion (140 micro g/kg per minute).
  
  
  RESULTS
  Serum leptin was significantly higher in obese than nonobese subjects (10.3 +/- 5.6 vs. 4.3 +/- 2.5 ng/mL, p < 0.01). Basal myocardial blood flow was not significantly different between obese and nonobese subjects. Adenosine-stimulated flow was blunted in obese (3.2 +/- 0.6 mL/g per minute) when compared with nonobese subjects (4.0 +/- 1.1 mL/g per minute, p < 0.05). Serum leptin concentration was inversely associated with adenosine-stimulated flow in study subjects (r = -0.50, p < 0.05). This association was no longer observed after adjustment for obesity and/or hyperinsulinemia.
  
  
  CONCLUSIONS
  Hyperleptinemia and reduced coronary vasoreactivity occur concomitantly in young obese but otherwise healthy men. Moreover, the adenosine-stimulated myocardial flow is inversely related to prevailing concentration of serum leptin. Although this relationship appears to be explained by obesity and/or hyperinsulinemia, leptin might have a role in regulation of myocardial blood supply.
authors.affiliation: Department of Medicine, Turku University, Turku, Finland. jan.sandell@utu.fi
authors.forename: Jan
authors.initials: J
authors.lastname: Sundell
authors.forename: Risto
authors.initials: R
authors.lastname: Huupponen
authors.forename: Olli T
authors.initials: OT
authors.lastname: Raitakari
authors.forename: Pirjo
authors.initials: P
authors.lastname: Nuutila
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000241:Adenosine; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006439:Hemodynamics; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D009765:Obesity / Q000097:blood* / Q000503:physiopathology*; D014055:Tomography, Emission-Computed
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D020738:Leptin; D000241:Adenosine; D009638:Norepinephrine