title: Low atmospheric pressure is associated with rupture of abdominal aortic aneurysms.
abstract: BACKGROUND
  the rate of rupture of abdominal aortic aneurysms (AAAs) has been shown to have a seasonal variation with more ruptures occurring during the winter months. One of the main meterological changes between the seasons is a change in atmospheric pressure. The aim of this study was to investigate whether there was any relationship between atmospheric pressure and the incidence of AAA rupture.
  
  
  METHODS
  all cases of ruptured AAA admitted to a single hospital over a ten year period were identified from hospital records. Daily atmospheric pressure readings from the nearest weather recording station to the hospital were obtained for the same period. Cases were only included if rupture could be confirmed by reviewing the patients case-notes.
  
  
  RESULTS
  admission rates for ruptured AAA showed a monthly variation with the highest rate in December and the lowest in August. There was a statistically significant correlation between the number of cases admitted in any particular month and the mean atmospheric pressure for the previous month. Neither daily minimum, maximum or mean pressure, weekly mean pressure or daily pressure variability were significantly different between those days when a ruptured AAA was admitted and those when no ruptured AAA was admitted.
  
  
  CONCLUSIONS
  low atmospheric pressure is associated with increased rate of AAA rupture. The method by which this change in pressure precipitates rupture cannot be determined from this study.
authors.affiliation: Department of Surgery, University of Leicester, Leicester, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bown
authors.forename: M J
authors.initials: MJ
authors.lastname: McCarthy
authors.forename: P R f
authors.initials: PR
authors.lastname: Bell
authors.forename: R D
authors.initials: RD
authors.lastname: Sayers
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology*; D001019:Aortic Rupture / Q000453:epidemiology*; D001274:Atmospheric Pressure; D006801:Humans; D012189:Retrospective Studies; D012621:Seasons; D006113:United Kingdom / Q000453:epidemiology