title: Sex differences in absolute myocardial perfusion. Non-invasive H2(15)O-PET in young healthy adults.
abstract: OBJECTIVE
  To investigate sex differences in myocardial perfusion especially in healthy individuals since former studies are rare and findings are controversial. Participants, methods: 26 subjects were enrolled: 16 healthy women (age: 34 ±7 years) were compared with 10 healthy men (age: 34 ± 3 years; p = ns). Myocardial blood flow (MBF) and coronary vascular resistance (CVR) were quantified at rest, during adenosine infusion and cold-pressor-testing, using positron emission tomography and radioactive-labelled water (H2(15)O-PET).
  
  
  RESULTS
  Women showed higher MBF than men at rest (1.10 ± 0.18 vs. 0.85 ± 0.20 ml/min/ml; p = 0.003) and cold-stress (1.39 ± 0.38 vs. 1.06 ± 0.28 ml/min/ml; p = 0.026). Corrected for rate-pressure-product, baseline findings maintained significance (1.41 ± 0.33 vs. 1.16 ± 0.19 ml/min/ml; p = 0.024). CVR was lower in women at baseline (81 ± 14 vs. 107 ± 22 mmHg*ml(-1)*min*ml; p = 0.006) and during cold-pressor-testing (71 ± 17 vs. 91 ± 20 mmHg*ml(-1)*min*ml; p = 0.013). Under adenosine neither maximal MBF (4.06 ± 1.0 vs. 3.91 ± 0.88 ml/min/ml; p = ns) nor coronary flow reserve (3.07 ± 1.12 vs. 3.44 ± 0.92; p = ns) nor CVR (24 ± 8 vs. 24 ± 6 mmHg*ml(-1)*min*ml; p = ns) showed sex-related differences.
  
  
  CONCLUSIONS
  Women show higher myocardial perfusion and lower coronary vascular resistance than men in physiologic states. Maximum perfusion and vasodilation under adenosine are not sex-specific.
authors.affiliation: Dr. med. Felix Range, Universitätsklinikum Düsseldorf, Klinik für Kardiologie, Pneumologie und Angiologie, Moorenstr. 5, 40225 Düsseldorf, Germany, Tel. +49/(0)211/811-88 00, Fax -95 20, Felix.Range@med.uni-duesseldorf.de.
authors.forename: Felix T
authors.initials: FT
authors.lastname: Range
authors.forename: Peter
authors.initials: P
authors.lastname: Kies
authors.forename: Klaus P
authors.initials: KP
authors.lastname: Schäfers
authors.forename: Günter
authors.initials: G
authors.lastname: Breithardt
authors.forename: Otmar
authors.initials: O
authors.lastname: Schober
authors.forename: Thomas
authors.initials: T
authors.lastname: Wichter
authors.forename: Michael A
authors.initials: MA
authors.lastname: Schäfers
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014867:Water
chemical_list: D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water
keywords: Sex differences; adenosine-induced hyperaemia; endothelium-dependent flow reserve; myocardial blood flow; positron emission tomography