The role of respiratory and upper airway neural control in sleep disordered breathing

Funded Activity Summary

Obstructive Sleep Apnea (OSA) is a disorder associated with snoring. It affects 4% of adult men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease eg. heart attacks and strokes. Patients with OSA obstruct the floppy portion of the upper airway (UA) during sleep and consequently experience frequent episodes of oxygen deprivation as well as sleep fragmentation. OSA is at least 2-3 times more common in men than women. While OSA patients seem, on average, to have smaller upper airways than normal subjects, the cause of OSA cannot be attributed to this factor alone. For example, a small UA cannot explain the male tendency for OSA. Abnormalities in breathing control or the control of upper airway muscles that normally hold the airway open might also be important in OSA. Men have previously been shown to have a greater increase in UA resistance during sleep than women, consistent with the idea that a gender difference in UA muscle control partly explains why more men than women have OSA. We aim to investigate how changes in breathing and UA dilator muscle control might lead to unstable patterns of breathing and to OSA. We propose that protective UA muscle reflexes are reduced during sleep more in men than women, and are reduced by low blood oxygen levels and alcohol (a known aggravator of sleep apnea). We further propose that low blood oxygen levels not only result from OSA but may also aggravate OSA by preferentially reducing the activity of UA dilating muscles, by making breathing patterns overall less stable and by depressing the ability of subjects to arouse from sleep to an airway blockage. We believe that this tendency to decrease UA activity may be exaggerated in OSA patients. We also propose that men are more vulnerable to the deleterious effects of low oxygen than women. We will also examine if men and snorers have exaggerated breathing responses on arousal from sleep.

Funded Activity Details

Start Date: 01-01-2001

End Date: 01-01-2003

Funding Scheme: NHMRC Project Grants

Funding Amount: $346,018.00

Funder: National Health and Medical Research Council

Research Topics

ANZSRC Field of Research (FoR)

Respiratory Diseases

ANZSRC Socio-Economic Objective (SEO)

There are no SEO codes available for this funding activity

Other Keywords

Alcohol effects on respiratory control | Breathing instability during sleep | Hypoxic ventilatory depression | Male susceptibility to Sleep Apnea | Obstructive sleep apnea | The pathogenesis of Sleep Apnea | Upper airway function

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