title: Breath isoprene--aspects of normal physiology related to age, gender and cholesterol profile as determined in a proton transfer reaction mass spectrometry study.
abstract: BACKGROUND
  This study was performed to clarify variations in breath isoprene concentrations with age, gender, body mass index (BMI) and total serum cholesterol. Our cohort consisted of 205 adult volunteers of different smoking background without health complaints. Total cholesterol in blood serum was measured in 79 of these volunteers.
  
  
  METHODS
  Mixed expiratory exhaled breath was sampled using Tedlar bags. Concentrations of isoprene were then determined using proton transfer reaction-mass spectrometry.
  
  
  RESULTS
  Isoprene concentrations ranged from 5.8 to 274.9 ppb, with an overall geometric mean (GM) of 99.3 ppb. There was no statistically significant difference in mean isoprene in breath between males and females (GM 105.4 and 95.5 ppb, respectively). Ageing led to a decrease in concentration in men, with an estimated slope of the regression line for log-transformed isoprene concentrations of -0.0049, but did not influence isoprene levels in women. We did not observe any significant correlation between isoprene breath content and cholesterol level in blood, even after adjusting for the possible influence of age. Similarly, no correlation was found between isoprene levels and BMI.
  
  
  CONCLUSIONS
  Isoprene concentrations in exhaled breath showed gender-specific correlations with respect to age. Further investigations are necessary to clarify the relation between isoprene concentrations in exhaled breath and cholesterol levels and synthesis rates in blood.
authors.affiliation: Department of Anaesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Ievgeniia
authors.initials: I
authors.lastname: Kushch
authors.forename: Barbora
authors.initials: B
authors.lastname: Arendacká
authors.forename: Svorad
authors.initials: S
authors.lastname: Stolc
authors.forename: Pawel
authors.initials: P
authors.lastname: Mochalski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Filipiak
authors.forename: Konrad
authors.initials: K
authors.lastname: Schwarz
authors.forename: Lukas
authors.initials: L
authors.lastname: Schwentner
authors.forename: Alex
authors.initials: A
authors.lastname: Schmid
authors.forename: Alexander
authors.initials: A
authors.lastname: Dzien
authors.forename: Monika
authors.initials: M
authors.lastname: Lechleitner
authors.forename: Viktor
authors.initials: V
authors.lastname: Witkovský
authors.forename: Wolfram
authors.initials: W
authors.lastname: Miekisch
authors.forename: Jochen
authors.initials: J
authors.lastname: Schubert
authors.forename: Karl
authors.initials: K
authors.lastname: Unterkofler
authors.forename: Anton
authors.initials: A
authors.lastname: Amann
mesh_terms: D000375:Aging; D015992:Body Mass Index; D001944:Breath Tests; D002070:Butadienes / Q000032:analysis*; D002138:Calibration; D002784:Cholesterol / Q000097:blood*; D045853:Exhalation; D005260:Female; D045782:Hemiterpenes / Q000032:analysis*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D010420:Pentanes / Q000032:analysis*; D012727:Sex Characteristics
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D002784:Cholesterol