Alcohol alters sensory processing to respiratory stimuli in healthy men and women during wakefulness.
OBJECTIVE
Alcohol can cause sleep-disordered breathing in healthy men, increase O2 desaturation in men who snore, and worsen obstructive sleep apnea (OSA) severity in men with OSA. These findings are less consistent among women, and the underlying mechanisms are incompletely understood. Respiratory-load sensory processing, which underpins upper-airway and respiratory responses to increased breathing load, is potentially impaired by alcohol. Using respiratory-related evoked potentials (RREPs) during wakefulness, this study aimed to test the hypothesis that alcohol impairs respiratory-load sensory processing and to explore potential sex differences.


METHODS
Within-subjects cross-over design in men versus women.


METHODS
Sleep physiology laboratory.


METHODS
Twenty healthy individuals (9 women) aged 18 to 38 years.


METHODS
Within each subject, RREP waveform components were generated by approximately 60 brief early-inspiratory negative-pressure pulses (-13 cm H2O mask pressure, 200 ms) before and after acute alcohol administration (1.5 mL/kg body weight). Choanal and epiglottic pressures were recorded to monitor stimulus magnitude and upper-airway resistance.


RESULTS
The latency of several RREP waveform components increased after the administration of alcohol (deltaN1 = 11 +/- 5 ms, deltaN2 = 6 +/- 3 ms, deltaP3 = 26 +/- 10 ms), and P2 amplitude decreased (3.4 +/- 1.5 microV vs 1.2 +/- 0.8 microV). There were no changes in P1 latency or amplitude. During relaxed breathing, nasal resistance increased after alcohol ingestion (1.38 +/- 0.16 vs 1.86 +/- 0.18 cm H2O x l(-1) x s(-1)), but pharyngeal and supraglottic resistances remained unchanged. RREP waveform components and upper-airway resistance measures were not different in men versus women before or after alcohol ingestion.


CONCLUSIONS
These data demonstrate that alcohol alters sensory processing of respiratory neural information, but not early neural transmission (P1), to a similar extent in healthy men and women. Altered sensory processing to respiratory stimuli, as well as nasal congestion, may be important mechanisms contributing to alcohol-related sleep disordered breathing.
Adelaide Institute for Sleep Health, Repatriation General Hospital, Daw Park, SA, Australia. deckert@rics.bwh.harvard.edu
Danny J
DJ
Eckert
Nathan J
NJ
Elgar
R Doug
RD
McEvoy
Peter G
PG
Catcheside
D000293:Adolescent; D000328:Adult; D000403:Airway Resistance / Q000187:drug effects*; D000428:Alcohol Drinking / Q000503:physiopathology*; D018592:Cross-Over Studies; D000431:Ethanol / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012119:Respiration / Q000187:drug effects*; D012677:Sensation / Q000187:drug effects*; D017678:Sex Distribution; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects*; D055815:Young Adult
D000431:Ethanol