title: Age and gender differences of endothelial function in 4739 healthy adults: the HUNT3 Fitness Study.
abstract: OBJECTIVE
  Endothelial dysfunction is an important marker for prognosis in patients with coronary heart disease. However, there are no reference values for endothelial function in a healthy population. Our aim was to determine the distribution of flow-mediated dilation (FMD) values by gender and age in healthy adults.
  
  
  METHODS
  FMD was measured by ultrasound during reactive hyperaemia in the brachial artery of 4739 adults aged 20-89 years, who were free from self-reported cardiovascular or pulmonary disease. Differences in FMD across age and gender were analysed by multiple linear regression.
  
  
  RESULTS
  Total mean ± SD FMD was 4.8 ± 4.2%, with corresponding estimates of 4.3 ± 3.9% for men and 5.3 ± 4.5% for women (p < 0.001). In total, 17% had FMD ≤0%, indicating endothelial dysfunction. FMD decreased with increasing age in both genders up to 70 years for men and 80 for women (p < 0.001). In women, age-related decline in FMD was steepest after age 45; in men, a steady decline after age 30. In men 80 years and older, FMD was higher than in men aged 50-79 years.
  
  
  CONCLUSIONS
  The distribution of FMD in this study is representative of the respective age and gender groups of a healthy population and may be a useful reference for future studies. The high proportion of endothelial dysfunction came as a surprise. Its age and gender distribution suggest that FMD ≤0% precedes cardiovascular disease and that it may be a powerful non-invasive biomarker for identifying high-risk individuals.
authors.affiliation: Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Eli-Anne
authors.initials: EA
authors.lastname: Skaug
authors.forename: Stian Thoresen
authors.initials: ST
authors.lastname: Aspenes
authors.forename: Line
authors.initials: L
authors.lastname: Oldervoll
authors.forename: Bjørn
authors.initials: B
authors.lastname: Mørkedal
authors.forename: Lars
authors.initials: L
authors.lastname: Vatten
authors.forename: Ulrik
authors.initials: U
authors.lastname: Wisløff
authors.forename: Oyvind
authors.initials: O
authors.lastname: Ellingsen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D016009:Chi-Square Distribution; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006306:Health Surveys; D064368:Healthy Volunteers; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D010809:Physical Fitness; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D014463:Ultrasonography; D014664:Vasodilation; D055815:Young Adult