title: Clinical correlates and heritability of flow-mediated dilation in the community: the Framingham Heart Study.
abstract: BACKGROUND
  Studies in selected samples have linked impaired endothelial function with cardiovascular disease and its risk factors. The clinical correlates and heritability of endothelial function in the community have not been described.
  
  
  RESULTS
  We examined a measure of endothelial function, brachial artery flow-mediated dilation (FMD), expressed as both percent (FMD%) and actual dilation by ultrasound with the occlusion cuff below the elbow in 2883 Framingham Study participants (52.9% women; mean age, 61 years). A subset of 1096 participants performed a 6-minute walk test before FMD determination. Mean FMD% was 3.3+/-3.0% in women and 2.4+/-2.4% in men. In stepwise multivariable linear regression models, FMD% was inversely related to age, systolic blood pressure, body mass index (BMI), lipid-lowering medication, and smoking, whereas it was positively related to female gender, heart rate, and prior walk test. The estimated heritability of FMD% was 0.14. FMD actual dilation findings were similar, except that female sex and BMI were not significantly associated.
  
  
  CONCLUSIONS
  Increasing age, systolic blood pressure, BMI, and smoking were associated with lower FMD% in our community-based sample, whereas prior exercise and increasing heart rate were associated with higher FMD%. The estimated heritability of FMD was modest. Future research will permit more complete characterization of the genetic and environmental determinants of endothelial function and its prognostic value in the community.
authors.affiliation: Evans Department of Medicine, Boston University School of Medicine, Framingham Study, Boston, Mass 01702-5827, USA. emelia@bu.edu
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
authors.forename: Martin G
authors.initials: MG
authors.lastname: Larson
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Keyes
authors.forename: Gary F
authors.initials: GF
authors.lastname: Mitchell
authors.forename: Ramachandran S
authors.initials: RS
authors.lastname: Vasan
authors.forename: John F
authors.initials: JF
authors.lastname: Keaney
authors.forename: Birgitta T
authors.initials: BT
authors.lastname: Lehman
authors.forename: Shuxia
authors.initials: S
authors.lastname: Fan
authors.forename: Ewa
authors.initials: E
authors.lastname: Osypiuk
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Vita
mesh_terms: D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014463:Ultrasonography; D014664:Vasodilation / Q000235:genetics