Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Obstructive sleep apnea (OSA) is temporary inhibition of breathing by complete or partial closure of the oropharynx, located in the posterior part of the throat, during sleep.
Suppression or complete cessation of breathing is a serious condition that requires treatment because it reduces the oxygen level in the blood, which is necessary for life.
Many comorbid, or concurrent, conditions are associated with OSA, including severe cardiovascular and endocrine disorders.
There’s also a high rate of comorbidity with OSA and other sleep disorders. Nearly one in three OSA patients has at least one concurrent sleep disorder. Early diagnosis and treatment of OSA is crucial for managing other co-occurring sleep problems.
OSA is a common breathing-related sleep disorder. The reported prevalence of OSA ranges between 2-18 percent in different studies with a known male predominance.[4,5]
However, these rates are just the tip of the iceberg as most OSA patients remain undiagnosed. The rates of undiagnosed OSA cases in the US are estimated to be 82 percent for men and 93 percent for women.
The coexistence of OSA and other sleep disorders is also quite common. For example, one study observed a concurrent sleep disorder in 31 percent of OSA patients.
When OSA goes undiagnosed, accompanying sleep disorders can further compromise overall health. Co-occurring sleep problems that are common in OSA patients are:
- Inadequate sleep hygiene
- Periodic limb movement disorder (PLMD)[8,9]
- Restless legs syndrome
Although the prevalence of OSA is higher in men, poor sleep hygiene and PLMD as comorbidities of OSA have been reported at higher rates in women.[3,4]
While the prevalence of poor sleep hygiene is 3 percent in the general population, this rate has been reported as 14.5 percent in patients with OSA.[3,13]
Similarly, the prevalence of narcolepsy in 2.5 percent in patients with OSA is considerably higher than in the general population.
OSA is mainly caused by having head-neck anatomy that resists airflow and sleep-related changes in upper airway functions.
OSA can wake the person from sleep with apnea/hypopnea attacks during the night, affecting sleep quality.
Even in advanced cases, since the person’s oxygen saturation remains low throughout the night, normal physiological functions other than sleep are also impaired.
The most obvious consequence of this situation is the emergence of inadequate sleep hygiene in a significant proportion of OSA patients.[3, 13]
Although the coexistence of OSA and insomnia is quite common, no common mechanism has been found.
On the other hand, a study has shown that there may be some metabolic changes common in many sleep disorders, including OSA and insomnia.
Excessive daytime sleepiness is the most common and important symptom of OSA.
This symptom may be the only complaint in many newly diagnosed or undiagnosed cases.
This clinical manifestation needs attention as it is a significant symptom of other sleep disorders accompanying OSA.
If the patient suffers from chronic daytime sleepiness, they should be evaluated for OSA and subsequent comorbid conditions.
OSA and related comorbid sleep disorders can have various consequences in the body in the long term through chronic stress. Conditions such as weight gain, depression, insulin resistance can be notable examples.
General risk factors for OSA include male sex, older age, family history, obesity, alcohol, some drugs, smoking, and having an anatomically narrow throat.
Individual risk factors for comorbid sleep problems accompanying OSA vary widely. These include genetic factors, stress, depression, and various metabolic disorders.
Depression is a risk factor for most sleeping disorders; however, the cause-effect relationship is often elusive. In a recent study, it was observed that the prevalence of comorbid sleep disorders increased in the presence of depression in OSA patients.
It’s crucial to identify the primary disorder in patients with comorbid conditions.
Did other disorders or symptoms arise from OSA, or did one of these other diseases cause OSA, or is there a different reason behind these diagnoses?
The above questions should be asked and answered professionally for correct and effective treatment. For this, an evaluation by a physician who specializes in sleep is vital.
Because of the overlapping symptoms, it’s not easy to detect or identify co-occurring sleep disorders in OSA patients.
The diagnosis of primary OSA and subsequent diagnosis of accompanying sleep problems, if any, should be made according to the current International Classification of Sleep Disorders.
Detailed sleep history and sleep diaries are also instrumental in the diagnosis process.
In addition, if your doctor deems it necessary, they may suggest polysomnography.
The first step in treating a patient with OSA and comorbid sleep disorders is to first treat the primary disorder. Lifestyle changes, CPAP therapy, oral appliances, and surgery are among the treatment options for OSA.
The diagnosis of comorbid sleep problems in most OSA patients can only be made after starting CPAP therapy. Full compliance with the OSA treatment process is of great importance.
After starting effective treatment of OSA, the physician can treat comorbid sleep problems.
Depending on the patient and the symptoms of the co-occurring condition, the physician may benefit from behavioral therapy or medication.
During follow-ups, the patient is re-evaluated, treatment efficacy is measured, and treatment is revised if necessary.
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