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Sources of variability in expiratory flow profiles during sleep in healthy young children

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
JournalRespiratory Physiology and Neurobiology
Early online date30 Nov 2019
Publication statusPublished - Mar 2020
Publication typeA1 Journal article-refereed


Standard lung function tests are not feasible in young children, but recent studies show that the variability of expiratory tidal breathing flow-volume (TBFV) curves during sleep is a potential indirect marker of lower airway obstruction. However, the neurophysiological sources of the TBFV variability in normal subjects has not been established. We investigated sleep stages and body position changes as potential sources for the TBFV curve variability. Simultaneous impedance pneumography (IP), polysomnography (PSG) and video recordings were done in 20 children aged 1-7 years without significant respiratory disorders during sleep. The early part of expiratory TBFV curves are less variable between cycles of REM than NREM sleep. However, within individual sleep cycles, TBFV curves during N3 are the least variable. The differences in TBFV curve shapes between sleep stages are the main source of overnight variability in TBFV curves and the changes in body position have a lesser impact.


  • Tidal breathing, Flow-volume curves, impedance pneumography, sleep stages, airway obstruction

Publication forum classification

Field of science, Statistics Finland