Common sleep medicine dogma states that chronic insomnia is a completely separate disorder from obstructive sleep apnea (OSA). But just like other seemingly disparate medical conditions, there’s increasing evidence that there may be a certain degree of overlap between these two conditions. It’s been shown that anywhere from 39 to 58% of patients with OSA also have insomnia. Conversely, up to 43% of older people with chronic insomnia were found to have undiagnosed sleep apnea.
It’s been stated that chronic insomnia and sleep apnea can co-exist together, but very few studies are saying the one could cause the other. To challenge this assumption, Dr. Barry Krakow and the Sleep and Human Health Institute is looking at the provocative theory that a large percentage of people with chronic insomnia have undiagnosed breathing problems during sleep.
I wrote in my book, Sleep, Interrupted, that almost every patient that I see with chronic insomnia has significantly narrow upper airways, and one or both parents snore heavily. Most chronic insomniacs prefer not to or absolutely can’t sleep on their backs, due to the tongue taking up relatively too much space within the confines of smaller jaws. When in deep sleep, especially when on their backs, the tongue can fall back due to gravity, and because of additional muscle relaxation, causes breathing pauses and an inability to stay asleep.
It’s also not surprising that most people with sleep maintenance insomnia keep waking up at various 90-120 minute intervals, usually around the same times. This makes sense since at the end of one sleep cycle, your muscles will be most relaxed. Not sleeping deeply can lead to chronic sleep deprivation, which causes adrenaline overload and a hyperactive nervous system, which you can’t shut down when you’re ready to go to sleep. This process can explain sleep onset insomnia. One recent study showed that sleep deprivation can even cause a kind of euphoria, which can lead to poor judgement and even addictive behaviors.
Maybe this is why cognitive behavioral therapy (CBT) for insomnia works very well, but not for everyone. There are numerous studies and personal experiences that confirm that treating the underlying sleep-breathing problem can fix the insomnia issues.
Granted, even if only 50% of people with chronic insomnia have obstructive sleep apnea, it’s likely that another 30 to 40% will have upper airway resistance syndrome (or UARS ), which is a huge topic that has been discussed elsewhere.