Upper airway sensation in snoring and obstructive sleep apnea

Area of Science:

• Sleep Medicine
• Respiratory Physiology
• Neurology

Background:

• Upper airway (UA) sensory receptors are crucial for maintaining airway patency and arousal during sleep.
• Impaired UA sensation may contribute to upper airway obstruction during sleep, as seen in obstructive sleep apnea (OSA).
• Previous research suggests a link between sensory function and airway stability.

Purpose of the Study:

• To investigate whether upper airway (UA) sensation is impaired in patients with obstructive sleep apnea (OSA).
• To determine if treatment with nasal continuous positive airway pressure (CPAP) improves UA sensation in OSA patients.
• To compare UA sensory function between OSA patients, nonapneic snorers (SN), and control subjects (CL).

Main Methods:

• Two-point discrimination (2PD) and vibratory sensation thresholds (VT) were measured in the UA, lip, and hand of 37 OSA patients, 12 SN, and 15 CL.
• Sensory thresholds were reassessed after 6 months in 23 CPAP-treated OSA patients and 18 untreated OSA patients.
• Statistical analyses were performed to compare sensory thresholds among groups and between pre- and post-treatment measurements.

Main Results:

• Both 2PD and VT were significantly reduced in the UA of OSA and SN subjects compared to CL subjects.
• No significant difference in UA 2PD or VT was found between OSA and SN groups.
• After 6 months, treated OSA patients showed significant improvement in UA VT, while untreated patients did not; UA 2PD and control site sensations remained unchanged in both groups.

Conclusions:

• A selective impairment in detecting mechanical stimuli exists in the upper airway (UA) of patients with obstructive sleep apnea (OSA) and snoring.
• This UA sensory deficit is partially reversible with nasal continuous positive airway pressure (CPAP) treatment in OSA patients.
• Findings suggest that impaired UA sensation is a characteristic feature of OSA and may be a modifiable factor.