title: Endothelial function, endothelin-1, and fibrinogen in young women using the vaginal contraceptive ring.
abstract: OBJECTIVE
  To assess the effects of the vaginal contraceptive ring cycle on indices of cardiovascular health and risk by studying healthy women during the active hormone phase compared with the ring-free phase of a standard 21/7-day cycle.
  
  
  METHODS
  Observational prospective cohort; 4 weeks' duration.
  
  
  METHODS
  Department of Human Physiology, University of Oregon.
  
  
  METHODS
  Twenty healthy women.
  
  
  METHODS
  Endothelial function testing using standard flow-mediated vasodilation of the brachial artery and sublingual nitroglycerin administration. All participants underwent venous blood collection.
  
  
  METHODS
  Endothelium-dependent and endothelium-independent vasodilation of the brachial artery using Doppler ultrasound imaging. Baseline levels of high-density lipoprotein, low-density lipoprotein, triglycerides, total cholesterol, endothelin-1, and fibrinogen.
  
  
  RESULTS
  The active hormone phase of the vaginal ring cycle showed significantly higher vasodilation compared with the ring-free phase. The active hormone phase also showed increased fibrinogen levels compared with the ring-free phase. Low-density lipoprotein lipid levels also fluctuated and were significantly higher during the ring-free phase.
  
  
  CONCLUSIONS
  Preliminary study observations of improved endothelial function and lowered low-density lipoprotein levels during the active hormone phase versus the ring-free phase suggest that the vaginal contraceptive ring has beneficial effects on vascular health in women.
authors.affiliation: Department of Human Physiology, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: Britta N
authors.initials: BN
authors.lastname: Torgrimson
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Meendering
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Miller
authors.forename: Paul F
authors.initials: PF
authors.lastname: Kaplan
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Minson
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000502:physiology*; D003274:Contraceptive Devices, Female; D019332:Endothelin-1 / Q000097:blood*; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005340:Fibrinogen / Q000032:analysis*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology
chemical_list: D019332:Endothelin-1; D005340:Fibrinogen