title: Day-time variation of serum periostin in asthmatic adults treated with ICS/LABA and adults without asthma.
abstract: BACKGROUND
  We aimed to determine the effect of sampling time during the day on serum periostin levels in adult participants with and without asthma.
  
  
  METHODS
  Serum periostin was measured at 2-h intervals from 0800 to 1800 h in 16 adult participants with stable asthma prescribed inhaled corticosteroid and long-acting beta-agonist therapy, and in 16 otherwise healthy participants without asthma. Mixed linear models were used to compare time zero (08:00 h) with subsequent measurement time for serum periostin for both groups.
  
  
  RESULTS
  In both asthma and non-asthma, the mean (SD) serum periostin levels continuously reduced during the day from 53.5 (13.6) ng/mL at 0800 h to 50.9 (13.4) ng/mL at 1800 h (difference log periostin -0.05, P ≤ 0.001) and 50.5 (13.0) ng/mL at 0800 h to 46.2 (11.5) ng/mL at 1800 h (difference log periostin -0.08, P ≤ 0.001) respectively.
  
  
  CONCLUSIONS
  Periostin values are higher in the morning compared with the afternoon in asthmatic and non-asthmatic adults. The small magnitude of the variation in serum periostin levels suggests that the time of day in which the serum periostin measurements are made is unlikely to influence treatment decisions if a specific serum periostin level is used to predict treatment responsiveness.Trial registrationAustralia New Zealand Trials Registry (ACTRN12614000072617).
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.|Victoria University of Wellington, Wellington, New Zealand.
authors.forename: Rachel
authors.initials: R
authors.lastname: Caswell-Smith
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.
authors.forename: Terrianne
authors.initials: T
authors.lastname: Cripps
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.
authors.forename: Thom
authors.initials: T
authors.lastname: Charles
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.|University of Auckland, Auckland, New Zealand.
authors.forename: Alexander
authors.initials: A
authors.lastname: Hosking
authors.affiliation: Genentech Inc, San Francisco, CA USA.
authors.forename: Meghana
authors.initials: M
authors.lastname: Handigol
authors.affiliation: Genentech Inc, San Francisco, CA USA.
authors.forename: Cecile
authors.initials: C
authors.lastname: Holweg
authors.affiliation: Genentech Inc, San Francisco, CA USA.
authors.forename: John
authors.initials: J
authors.lastname: Matthews
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Holliday
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.
authors.forename: Corentin
authors.initials: C
authors.lastname: Maillot
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.
authors.forename: James
authors.initials: J
authors.lastname: Fingleton
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.|University of Otago, Wellington, New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Weatherall
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.|Victoria University of Wellington, Wellington, New Zealand.|Capital & Coast District Health Board, Wellington, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Beasley
authors.affiliation: Medical Research Institute of New Zealand, Private Bag 7902, Wellington, 6242 New Zealand.|Victoria University of Wellington, Wellington, New Zealand.|Capital & Coast District Health Board, Wellington, New Zealand.
authors.forename: Irene
authors.identifier: 0000-0001-5327-3027
authors.initials: I
authors.lastname: Braithwaite
keywords: Asthma; Biomarker; Daytime variation; Periostin