title: Breath acetone to monitor life style interventions in field conditions: an exploratory study.
abstract: OBJECTIVE
  To assess whether breath acetone concentration can be used to monitor the effects of a prolonged physical activity on whole body lipolysis and hepatic ketogenesis in field conditions.
  
  
  METHODS
  Twenty-three non-diabetic, 11 type 1 diabetic, and 17 type 2 diabetic subjects provided breath and blood samples for this study. Samples were collected during the International Four Days Marches, in the Netherlands. For each participant, breath acetone concentration was measured using proton transfer reaction ion trap mass spectrometry, before and after a 30-50 km walk on four consecutive days. Blood non-esterified free fatty acid (NEFA), beta-hydroxybutyrate (BOHB), and glucose concentrations were measured after walking.
  
  
  RESULTS
  Breath acetone concentration was significantly higher after than before walking, and was positively correlated with blood NEFA and BOHB concentrations. The effect of walking on breath acetone concentration was repeatedly observed on all four consecutive days. Breath acetone concentrations were higher in type 1 diabetic subjects and lower in type 2 diabetic subjects than in control subjects.
  
  
  CONCLUSIONS
  Breath acetone can be used to monitor hepatic ketogenesis during walking under field conditions. It may, therefore, provide real-time information on fat burning, which may be of use for monitoring the lifestyle interventions.
authors.affiliation: Department of Molecular and Laser Physics IMM, Radboud University, Nijmegen, the Netherlands.
authors.forename: Devasena
authors.initials: D
authors.lastname: Samudrala
authors.forename: Gerwen
authors.initials: G
authors.lastname: Lammers
authors.forename: Julien
authors.initials: J
authors.lastname: Mandon
authors.forename: Lionel
authors.initials: L
authors.lastname: Blanchet
authors.forename: Tim H A
authors.initials: TH
authors.lastname: Schreuder
authors.forename: Maria T
authors.initials: MT
authors.lastname: Hopman
authors.forename: Frans J M
authors.initials: FJ
authors.lastname: Harren
authors.forename: Luc
authors.initials: L
authors.lastname: Tappy
authors.forename: Simona M
authors.initials: SM
authors.lastname: Cristescu
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000096:Acetone / Q000032:analysis*; D000328:Adult; D000368:Aged; D001944:Breath Tests; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007659:Ketones / Q000378:metabolism; D008019:Life Style; D008066:Lipolysis / Q000502:physiology; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*
chemical_list: D005230:Fatty Acids, Nonesterified; D007659:Ketones; D000096:Acetone; D005947:Glucose; D020155:3-Hydroxybutyric Acid