title: The effect of aging on venous valves.
abstract: OBJECTIVE
  Age is the strongest risk factor for venous thrombosis. Vessel wall changes such as thickening of venous valves may be one of the contributing mechanisms. We determined thickness and function of venous valves in the popliteal vein with ultrasound in 77 healthy individuals.
  
  
  RESULTS
  The study included 6 age groups ranging from 20 to 80 years old. Thickness of the valves was compared between age groups. Valve closure time was assessed as an indicator for valve function. In 69 of 77 participants, valve parameters could be measured. We found an increasing thickness of the valves with age, with a mean thickness of 0.35 mm (range, 0.25 to 0.44 mm) in the group of 20 to 30 years and 0.59 mm (range, 0.30 to 1.21 mm) in the group of 71 to 80 years. The increase in valve thickness per year (linear regression coefficient) was 0.004 mm (95% CI, 0 to 0.009). Valve function was not directly associated with age. Valve thickness, however, was inversely associated with valve function.
  
  
  CONCLUSIONS
  Our results show that deep venous valves change with age, with thicker valves in older individuals. The increase of valve thickness with age may be part of the explanation for the age gradient seen in the incidence of venous thrombosis.
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Kirsten
authors.initials: K
authors.lastname: van Langevelde
authors.forename: Alexandr
authors.initials: A
authors.lastname: Srámek
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D055422:Venous Valves / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult