For sufferers of obstructive sleep apnea, it doesn't take much for performance, precision and alertness to degrade dramatically. It doesn't take much alcohol, and it doesn't take many hours of sleep deficit either, for things to get really dangerous, new research has found.
Sleep apnea is a condition in which a sleeper stops breathing repeatedly in the night for long periods of time. It affects more than 12 million adults -- and disproportionately strikes males, obese people and those older than 40. Daytime sleepiness is its most immediate consequence. But over time, suffering from sleep apnea heightens a person's risk of high blood pressure and metabolic problems, including type 2 diabetes.
It turns out that the risk of a driving accident also increases --and even more if sleep apnea is compounded by alcohol consumption or short sleep.
In a 90-minute driving simulator, the performance of subjects with sleep apnea was compared to that of subjects without the condition. People in each group conducted a simulator session under three conditions: after unrestricted sleep, after a single night with only four hours of sleep, and after consuming enough alcohol to attain a blood-alcohol level of 0.05% (lower than the 0.08% observed by most states as the definition of intoxicated).
In all cases, those with sleep apnea were more likely than their healthy-sleeping peers to swerve and veer off-course. And even with a full night's sleep, those with sleep apnea were 10% likelier to have a crash than subjects who slept without breathing interruption. At a blood alcohol level well short of drunk, the sleep apnea group was 21% more likely to crash the simulated car than were their peers who slept well. On only four hours of sleep, sleep apnea sufferers were 32% more likely to crash than were healthy sleepers.
For those with sleep apnea, the Australian researchers suggested that even moderate alcohol consumption or a single night of short sleep can be dangerous and should be avoided if safety and alertness are at issue. Their study is published in the Annals of Internal Medicine dated Oct. 6, 2009.
-- Melissa Healy
Wonder if you could have sleep apnea? Here's a quick test.