Comorbid Insomnia and Obstructive Sleep Apnea: Double Trouble

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Obstructive sleep apnea (OSA) and chronic insomnia are challenging enough as individual conditions. But together—they pose some real risks. If nearly 3 in 10 people with OSA also have chronic insomnia, as studies suggest, the major question becomes: are your prescribed home sleep apnea tests catching indications of chronic insomnia?

Chronic insomnia and OSA are 2 common sleep disorders, and both are considered independent risk factors for heart disease.1 Both have also been independently associated with other serious medical conditions beyond cardiovascular disease, including cerebrovascular disease, depression, dementia, and cancer.

These facts send an urgent message to the sleep medicine community to question patients fully during screening and to gather as much patient data as possible from prescribed sleep tests. A test to determine whether a patient has sleep apnea could overlook comorbidities like insomnia, which may be underreported by patients. Looking at the apnea-hypopnea index (AHI) alone may not be enough. 

A recent study showed out of 476 patients with OSA studied, nearly 30% had significant insomnia.1 Nearly twice as many patients in that group (OSA+I) were female. Additionally, the OSA+I patients had higher rates of heart disease—more than twice as high as those with only OSA.1 Finally, the OSA+I group also showed lower quality of life, lower quality of sleep, higher sleep propensity, and higher depression.1

This study was conducted in Korea, which reminds us that sleep apnea is a global problem.1 Fortunately, it is also studied globally, and each of us can play a role contributing to solving the problem. 

We have a difficult task. Not only did the study indicate a high prevalence of comorbid insomnia with OSA, but it also suggested that comorbid insomnia with OSA may constitute a cumulative risk factor for cardiovascular disease.1

Going forward, the authors of the study noted the higher rate of cardiovascular diseases among patients in the OSA+I group “establishes a strong association, rather than a causality; therefore, it warrants further investigations into its pathophysiology, which would help devise risk reduction strategies and treatment options.”1

In the meantime, until more research is done, every questionnaire, every test, and every diagnostic improvement are developments toward more widely and fully treating sleep disorders. 

References:

  1. Cho YW, Kim KT, Moon H, Korostyshevskiy VR, Motamedi GK, Yang KI. Comorbid insomnia with obstructive sleep apnea: clinical characteristics and risk factors. J Clin Sleep Med. 2018;14(3):409-417. doi: 10.5664/jcsm.6988