title: Influence of seasonal variation on blood pressure measurements in children, adolescents and young adults.
abstract: BACKGROUND
  Seasonal fluctuations in outdoor temperature have been shown to affect blood pressure in adults. The aim of our study was to determine whether blood pressure measurements in children and adolescents in Central Europe undergo seasonal variation or are influenced by outdoor temperature.
  
  
  METHODS
  The blood pressure of 6,714 subjects (3,497 boys, 3,237 girls) aged 3 to 21 (median age 10.6) years was routinely measured. The study cohort comprised both healthy and sick children and adolescents visiting outpatient clinics and during hospitalisation.
  
  
  RESULTS
  Cross-sectional analysis showed a significant seasonal variation in blood pressure measurements. The mean increase of systolic/diastolic blood pressure was 4.45/2.42 mmHg during the winter. A significant correlation between average outdoor temperature and systolic blood pressure was found (ρ = -0.074 p < 0.001). However, the effect was only detectable at an average temperature below 0 °C/32 °F and above 10 °C/50 °F. For each 1 °C increase in average outdoor temperature, the systolic blood pressure fell by 0.12 mmHg.
  
  
  CONCLUSIONS
  Blood pressure measurements in children and adolescents, even in a temperate climate, are influenced by temperature and subject to seasonal variation. Considering seasonal variations in blood pressure could be of clinical interest.
authors.affiliation: Center for Pediatric Research, Department of Woman and Child Health, University Hospital for Children and Adolescents, University of Leipzig, Liebigstraße 20a, 04103, Leipzig, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Miersch
authors.forename: Mandy
authors.initials: M
authors.lastname: Vogel
authors.forename: Ruth
authors.initials: R
authors.lastname: Gausche
authors.forename: Werner
authors.initials: W
authors.lastname: Siekmeyer
authors.forename: Roland
authors.initials: R
authors.lastname: Pfäffle
authors.forename: Katalin
authors.initials: K
authors.lastname: Dittrich
authors.forename: Wieland
authors.initials: W
authors.lastname: Kiess
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001794:Blood Pressure; D001795:Blood Pressure Determination; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D055815:Young Adult