title: Central aortic blood pressure of hypertensive men during short-term cold exposure.
abstract: BACKGROUND
  Short- and long-term exposures to cold increase blood pressure and may explain the higher wintertime cardiovascular morbidity and mortality. Hypertensive subjects may be more susceptible to adverse cold-related cardiovascular health effects. The aim of our study was to assess the effect of short-term cold exposure on central aortic blood pressure among untreated hypertensive men.
  
  
  METHODS
  We conducted a population-based recruitment of 41 hypertensive men and a control group of 20 men without hypertension (aged 55-65 years) who underwent whole-body cold exposure (15-minute exposure to temperature -10 °C, wind 3 m/s, winter clothes). Central aortic blood pressure, augmentation index, and subendocardial viability ratio were measured by radial artery applanation tonometry.
  
  
  RESULTS
  Short-term cold exposure increased the central aortic blood pressure similarly both in both hypertensive men, from 130/93 to 162/107 mm Hg (P < 0.001) and men in the control group, from 114/81 to 142/91 mmHg (P < 0.001). Augmentation index increased by 12% (from 10% to 22%, P < 0.001; and from 16% to 28%, P < 0.001, respectively), whereas subendocardial viability ratio decreased 10% (from 188% to 177%, P = 0.001; and from 203% to 193%, P = 0.01, respectively) during cold exposure in both hypertensive men and control subjects.
  
  
  CONCLUSIONS
  Short-term cold exposure increases central aortic blood pressure and cardiac workload, and myocardial oxygen demand slightly increases in relation to blood supply in untreated hypertensive middle-aged men. Because of the higher baseline blood pressure among hypertensive subjects, the cold-induced rise in central aortic blood pressure may increase the risk of adverse cardiovascular health effects.
authors: Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland.
authors: Heidi
authors: H
authors: Hintsala
authors: Arno
authors: A
authors: Kandelberg
authors: Karl-Heinz
authors: KH
authors: Herzig
authors: Hannu
authors: H
authors: Rintamäki
authors: Matti
authors: M
authors: Mäntysaari
authors: Aino
authors: A
authors: Rantala
authors: Riitta
authors: R
authors: Antikainen
authors: Sirkka
authors: S
authors: Keinänen-Kiukaanniemi
authors: Jouni J K
authors: JJ
authors: Jaakkola
authors: Tiina M
authors: TM
authors: Ikäheimo
mesh_terms: D000368:Aged; D001011:Aorta / Q000503:physiopathology*; D062186:Arterial Pressure; D001833:Body Temperature Regulation; D001916:Brachial Artery / Q000503:physiopathology; D016022:Case-Control Studies; D003080:Cold Temperature; D005387:Finland; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology*; D007035:Hypothermia / Q000503:physiopathology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D013997:Time Factors
keywords: aorta; augmentation index; blood pressure; cold temperature; hypertension; subendocardial viability ratio.