title: Rapid weather changes are associated with increased ischemic stroke risk: a case-crossover study.
abstract: Observational studies focusing on absolute meteorological values suggest an association between meteorological parameters and stroke risk but these results are inconsistent and conflicting. Since changes in weather can provoke atrial fibrillation, we examined the association between rapid weather changes and stroke risk in 1694 patients with determinable onset of stroke symptoms in a case-crossover study in central Germany. Days one to three before stroke onset were classified as hazard periods and day seven as the respective control period. Risk of ischemic stroke in relation to 24 h differences in mean ambient temperature, relative humidity and atmospheric pressure was determined. The association between temperature and stroke risk appears to be close to linear with an increase in stroke risk of 11 % (odds ratio 1.11, 95 % confidence interval 1.01-1.22) for each 2.9 °C temperature decrease over 24 h. In individuals with a higher cardiovascular risk, stroke risk increased by 30 % (1.30, 1.06-1.61). Risk for cardioembolic strokes increased by 26 % (1.26, 1.06-1.50). Rapid positive or negative changes in relative humidity (>5 %) and atmospheric pressure (>10 hPa) increased stroke risk by a maximum of 30 % (1.30, 1.02-1.66) and 63 % (1.63, 1.10-2.42). In individuals with a higher cardiovascular risk, rapid changes in atmospheric pressure were associated with a four-times higher stroke risk (4.56, 1.26-16.43). Our results suggest that rapid decreases in ambient temperature and rapid changes in relative humidity and atmospheric pressure increase stroke risk under temperate climate conditions. Individuals with a high cardiovascular risk profile seem to be at greater risk.
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany. florian.rakers@med.uni-jena.de.|Department of Neurology, Helios Hospital Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. florian.rakers@med.uni-jena.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Rakers
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Schiffner
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Rupprecht
authors.affiliation: Institute of Medical Statistics, Computer Sciences and Documentation, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Brandstädt
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Otto W
authors.initials: OW
authors.lastname: Witte
authors.affiliation: Institute of Medical Statistics, Computer Sciences and Documentation, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Walther
authors.affiliation: Institute of Medical Statistics, Computer Sciences and Documentation, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Schlattmann
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Bachstrasse 18, 07743, Jena, Thuringia, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwab
mesh_terms: D000368:Aged; D001274:Atmospheric Pressure; D016022:Case-Control Studies; D018592:Cross-Over Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012621:Seasons; D020521:Stroke / Q000453:epidemiology*; D013696:Temperature; D014887:Weather
keywords: Cerebrovascular disease; Infarction; Stroke; Stroke prevention; Weather