Is It Insomnia, Sleep Apnea...or Both?
So many patients I’ve seen in the sleep clinic repeat these three common refrains:
“I’m so tired during the day, it’s like I never sleep at night.”
“I fall asleep only to wake up repeatedly.”
“I’ve tried all the sleeping pills and none of them work.”
I can only speak anecdotally as a registered polysomnographic sleep technologist (RPSGT), but let me share this: many of these patients end up with a diagnosis of sleep-disordered breathing.*
Sometimes, insomnia arrives as the consequence of having an identified and untreated sleep disorder.
Other common sleep villains to consider: restless legs syndrome (RLS) and its cousin, periodic leg movement disorder (PLMD). What’s become more important—the need to thoroughly investigate a case of sleeplessness. When insomnia appears to be untreatable with medication, this can signal other problems.
A brief history of links between insomnia and sleep apnea
Links between obstructive sleep apnea (OSA) and insomnia have been observed formally since respected sleep researcher Christian Guilleminault first identified them in a paper published in 1973.1
Meanwhile, the last few decades have seen the clinical definitions of insomnia change as researchers strive to better understand the mechanisms that can lead to sleeplessness.
In sleep clinics, the common approach to complaints of sleeplessness has mostly involved behavioral medicine approaches. Unfortunately, this means many people miss an opportunity to undergo a sleep study to rule out other causes.
Today, more sleep specialists and even some primary care providers now screen more comprehensively for other sleep disorders when examining patients whose chief complaints begin with insomnia.
What we know in 2020
While research continues to dig into the roots of insomnia, sleep scientists have revealed some likely causes. For instance: Medications we take for other physical or mental health conditions can contribute to both insomnia and daytime sleepiness.2
Certain behaviors that qualify as “poor sleep hygiene” may be root causes for sleeplessness—chief among them, the terrible habit we all share (myself included) of checking handheld electronic devices at bedtime, or even while in bed with the lights out, leading to circadian rhythm disruption.3
Dr. Barry Krakow is the sleep researcher credited with major sleep research papers published between 2000 and 2017 which connect treatment-resistant insomnia to undiagnosed OSA.4-6
His most groundbreaking research appeared in Mayo Clinic Proceedings in September 2014, in which Krakow found that more than 91 percent of subjects with insomnia, who’d failed prescribed sleep aids, met standard criteria for moderate to severe OSA.7
This makes treatment options extremely problematic. Some insomnia drugs can depress the respiratory system during sleep, which worsens preexisting cases of OSA.
The Krakow study’s senior research investigator, Victor Ulibarri, also observed that “remarkably, greater than 70 percent of this patient population reported sleep breathing symptoms like snoring or gasping during sleep and suffered from insomnia for an average of a decade, yet none of these patients had previously been evaluated or referred for sleep testing.”8
When asked why he initially thought to study breathing patterns in insomnia patients who weren’t complaining of traditional OSA symptoms, Dr. Krakow replied:
We asked insomnia patients to tell us why they wake up and found that the causes they attribute to their awakenings are very different from what we see in the sleep lab. Fifty percent say it’s mental and 50 percent say it’s physical. They’ll also point to things after the fact, such as, ‘I woke up because my mind is racing,’ and then realize that the racing thoughts really emerged after the awakening. In the lab, however, breathing events were the most common cause of their awakenings.9
Is it always one or the other?
No. You can also be diagnosed with comorbid insomnia and OSA (COMISA), also described as “complex insomnia.”10 Dr. Krakow published research in 2013 which observed that “sleep breathing complaints were extremely common among a large sample of treatment-seeking, self-identified, adult chronic insomnia patients.”11
COMISA describes experiencing both clinically measurable insomnia (not caused by OSA) and OSA simultaneously. It can be confirmed in patients with well-treated OSA who still experience insomnia.12,13
Tricky to identify and often overlooked, COMISA requires a sleep study to confirm. Once diagnosed, patients have treatment options that include cognitive behavior therapy for insomnia (CBT-i) matched with continuous positive airway pressure (CPAP) therapy.14,15
If you’re unsure about your sleeplessness, ask for a sleep specialist referral. Insomnia shouldn’t be something you’re forced to live with. Meanwhile, if you can “catch” a separate sleep disorder “in the act,” you’ll be able to treat it as well.
*Sleep-disordered breathing includes things like OSA, central sleep apnea, snoring, and upper airway resistance.
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