Modulation of the ultradian human nasal cycle by sleep stage and body position.
Level 4 - case-series / case-control
Small observational physiological case series in six participants
PubMed 28099555 · doi:10.1590/0004-282X20160178
What was done
Left- and right-side nasal airflow was measured in six subjects during an eight-hour sleep period using nasal thermistors. Participants underwent polysomnography to determine sleep stages (REM vs. non-REM), while body position was simultaneously tracked via video with infrared lighting to evaluate positional and sleep-stage influences on nasal airflow lateralization.
What was found
Airflow through the right nasal chamber relative to the left was significantly greater during REM sleep than during non-REM sleep (p < 0.001). Both body position (p < 0.001) and sleep stage (p < 0.001) significantly influenced nasal airflow lateralization. Absolute flow values and effect sizes were not provided in the abstract.
Why it matters
This study provides evidence linking ultradian autonomic nasal cycle shifts to REM/non-REM sleep architecture and asymmetrical body position inputs.
Limits
The sample size is extremely small (n = 6), severely limiting generalizability. The abstract does not specify participant demographics, baseline health status, or specific quantitative airflow differences beyond p-values.