We often talk about sleep apnea in terms of quality of life. We discuss sleepiness, depressive symptoms, or general sluggishness, and we examine whether sleep apnea has detrimental effects on these qualities. But can sleep apnea affect your life to a worse degree? In other words, can it kill you? If you are someone who drives, perhaps. As we know, a lack of sleep affects reaction time and alertness – two things that are very important when driving! So does sleep apnea affect driving skills?
A recent study put two populations of people through a driving simulator: those who are at risk for sleep apnea, and those who are not. To be clear, the “at risk” group had not been diagnosed with sleep apnea, they were those who likely had sleep apnea (identified via the Berlin Questionnaire) based on their weight and symptoms. It is difficult to find people who have diagnosed sleep apnea but are willing to go untreated to participate in a study, so sometimes this is the best a researcher can do.
The driving simulator consisted of two phases: a reaction time test and a peripheral vision distraction test (which requires alertness). The performance levels were compared between at-risk and non-at-risk subjects. Subjects were also asked about their history of automobile accidents.
Results found that many more at-risk subjects failed the reaction time portion of the driving simulation than did the non-at-risk population (47% vs. 28%). Interestingly, there was no difference in performance for the peripheral vision distraction test, but there was a difference in performance between those who were obese and those who were not obese. And finally, not surprisingly, those who reported the highest sleepiness levels had a higher amount of driving accidents than those who were not sleepy.
This study reported that those who are at risk for having sleep apnea had poorer reaction time in a driving simulator. It also showed that obese subjects had a more difficult time in a task that required vigilance and attention. If we consider that none of these subjects had undergone testing for sleep apnea, it may be that the more obese subjects do indeed have apnea but have not been diagnosed. If this were the case, it would be likely that what is causing the attentional deficit is untreated apnea and not obesity. However, the obesity itself could be limiting cognitive functioning independently of sleep apnea. Future studies should attempt to replicate this study by comparing diagnosed but untreated sleep apnea subjects with those who do not suffer from sleep apnea.Pre-publication: “The relationship between driving simulation performance and obstructive sleep apnoea risk, daytime sleepiness, obesity and road traffic accident history of commercial drivers in Turkey.” Journal: Sleep and Breathing.