Insomnia and sleep apnea are two common sleep disorders that were believed to be independent of each other. While this may be true for some individuals, there is increasing evidence linking obstructive sleep apnea and insomnia with each other.
○ The link between insomnia and obstructive sleep apnea
It's been recognized for some time that chronic insomnia and sleep apnea can co-exist together.
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.
Dr. Barry Krakow's Study
Study Objective: The study was run to help answer a unique and intriguing question: what causes an insomniac to wake up at night?
Method & Results: Dr. Krakow and his colleagues first removed from the study group all the patients that failed screening for sleep apnea. 20 patients that passed screening (in other words, they did not appear to be suffering from sleep apnea based on physical traits or based on their answers to the Epworth Sleepiness Test) were used in the study and the results were startling:
- 18 of the 20 patients were found to be suffering from sleep disordered breathing that was causing them to wake up after falling asleep
- 11 of those patients were found to be suffering from obstructive sleep apnea with an average AHI of 14.4 (an AHI of 15 is considered to be moderate sleep apnea)
Hence, if you are an insomniac who wakes during the night you should consider asking your doctor to be tested for sleep apnea.
In his interview with Dr. Steven Park, Dr. Barry Krakow talked in detail about the co-occurance of Insomnia and Sleep Apnea, and how the two are interlinked.
Here's Dr. Barry Krakow's interview:
Here's the details of another study published on PMC.
Study Objectives: To review studies examining the cooccurrence of insomnia and obstructive sleep apnea (OSA), explore evidence for the effect of OSA therapy on insomnia symptoms and the effect of insomnia treatments on breathing and sleep in patients with OSA, and discuss challenges in the evaluation and treatment of comorbid insomnia and OSA.
Methods/Results: Seven pertinent studies were identified that assessed the prevalence of comorbid insomnia and OSA or sleep disordered breathing.
Four studies were identified that examined the effects of OSA treatment in patients with insomnia, and 8 studies were found that examined hypnotic use in patients with OSA or sleep disordered breathing.
A high prevalence (39%-58%) of insomnia symptoms have been reported in patients with OSA, and between 29% and 67% of patients with insomnia have an apnea-hypopnea index of greater than 5.
Conclusions: Insomnia and OSA frequently cooccur. The optimal strategy for adequately treating comorbid insomnia and OSA remains unclear.
Future research examining the impact of insomnia on continuous positive airway pressure therapy is needed.
Given the substantial overlap in symptoms between insomnia and OSA, evaluation and treatment of these 2 conditions can be challenging and will require multidisciplinary collaboration among sleep specialists.
○ Wrapping Up
Increasing evidence suggests that there is a certain degree of overlap between insomnia and sleep apnea.
Sleep apnea causes secondary chronic insomnia, as a result of the breathing pauses an individual experiences during an apneic episode. When a person awakens every time they try to catch their breath, they might have difficulty in falling back asleep.
If this scenario happens every night, then the patient may develop insomnia over time.
It's important to practice good Sleep Hygiene to minimize symptoms of sleep apnea.