Signs of both motor and sensory nervous lesions have previously been shown in the upper airway of obstructive sleep apnea (OSA) patients and habitual snorers.
snoring per se may damage all upper airway neurons over time, thereby causing progression to manifest sleep apnea. To test this, non-snoring subjects, untreated snorers and CPAP-treated patients underwent repeated sensory testing in the soft palate in a prospective long-term study.
Cold detection threshold (CDT) testing at soft palate and lip with a thermode and nocturnal respiratory recordings were performed in 2008/2009 with retesting 6 -7 years later.
In 25 untreated snorers palatal CDT worsened from median 4.2 °C (3,2 – 5,9) to 11.0 °C (7,0 – 17,4) (p<0.001). AHI increased from median 7.0 to 14.0/h (p<0.05. In 21 non-snoring control subjects palatal CDT increased from median 3.2 °C to 5.6 °C (p<0.005). There was a significant correlation between changes in CDT and AHI. In 19 CPAP-treated patients palatal CDT did not significantly change; 8 patients had improved values. CDT worsened significantly more in the snorers group than in both controls (p<0.05) and CPAP patients (p<0.001). There was no significant difference between controls and CPAP-patients.
CDT worsened considerably over time in untreated snorers, significantly more than non-snoring controls and CPAP-patients. Untreated snorers therefore risk developing poor sensitivity in the upper airway. In contrast, efficient treatment of OSA seems to protect the sensory innervation, since the CPAP-treated group maintained their sensitivity to cold, and in some cases, the sensitivity even improved.

Copyright © 2020. Published by Elsevier Inc.