Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Epidemiology | Pathophysiology | Clinical Presentations | Risk factors | Diagnosis | Management
Overview
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.[1]
Many comorbid, or concurrent, conditions are associated with OSA,[2] 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.[3] Early diagnosis and treatment of OSA is crucial for managing other co-occurring sleep problems.
Epidemiology
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.[6]
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[7]
- Periodic limb movement disorder (PLMD)[8,9]
- Restless legs syndrome[10]
- Narcolepsy[11]
- Insomnia[12]
- Hypersomnia
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.[3]
The coexistence of OSA and insomnia is also not uncommon. In some studies, the prevalence of insomnia in OSA patients has been reported as high as 39 percent.[11]
Pathophysiology
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.[14]
On the other hand, a study has shown that there may be some metabolic changes common in many sleep disorders, including OSA and insomnia.
New research suggests that the coexistence of narcolepsy and OSA may result from changes related to the REM sleep phase.[15]
Clinical Presentations
Excessive daytime sleepiness is the most common and important symptom of OSA.[16]
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.[17] Conditions such as weight gain, depression, insulin resistance can be notable examples.
Clinical presentation of OSA differs with gender. While snoring and apnea are more common in men, excessive daytime sleepiness and insomnia are more common symptoms/comorbid conditions in women.[14]
Risk factors
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.[10]
Diagnosis
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.[18]
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.
Management
The first step in treating a patient with OSA and comorbid sleep disorders is to first treat the primary disorder.[19] 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.[3] 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.
References:
1. Rundo J. V. (2019). Obstructive sleep apnea basics. Cleveland Clinic journal of medicine, 86(9 Suppl 1), 2–9. https://doi.org/10.3949/ccjm.86.s1.02
2. Shahar, E., Whitney, C. W., Redline, S., Lee, E. T., Newman, A. B., Nieto, F. J., O’Connor, G. T., Boland, L. L., Schwartz, J. E., & Samet, J. M. (2001). Sleep-disordered breathing and cardiovascular disease: cross-sectional results of the Sleep Heart Health Study. American journal of respiratory and critical care medicine, 163(1), 19–25. https://doi.org/10.1164/ajrccm.163.1.2001008
3. Scharf, S. M., Tubman, A., & Smale, P. (2005). Prevalence of concomitant sleep disorders in patients with obstructive sleep apnea. Sleep & breathing = Schlaf & Atmung, 9(2), 50–56. https://doi.org/10.1007/s11325-005-0014-1
4. Franklin, K. A., Sahlin, C., Stenlund, H., & Lindberg, E. (2013). Sleep apnoea is a common occurrence in females. The European respiratory journal, 41(3), 610–615. https://doi.org/10.1183/09031936.00212711
5. Young, T., Palta, M., Dempsey, J., Skatrud, J., Weber, S., & Badr, S. (1993). The occurrence of sleep-disordered breathing among middle-aged adults. The New England journal of medicine, 328(17), 1230–1235. https://doi.org/10.1056/NEJM199304293281704
6. Young, T., Evans, L., Finn, L., & Palta, M. (1997). Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women. Sleep, 20(9), 705–706. https://doi.org/10.1093/sleep/20.9.705
7. Jung, S. Y., Kim, H. S., Min, J. Y., Hwang, K. J., & Kim, S. W. (2019). Sleep hygiene-related conditions in patients with mild to moderate obstructive sleep apnea. Auris, nasus, larynx, 46(1), 95–100. https://doi.org/10.1016/j.anl.2018.06.003
8. Exar, E. N., & Collop, N. A. (2001). The association of upper airway resistance with periodic limb movements. Sleep, 24(2), 188–192. https://doi.org/10.1093/sleep/24.2.188
9. Kim, H. J., & Lee, S. A. (2020). Periodic limb movements during sleep may reduce excessive daytime sleepiness in men with obstructive sleep apnea. Sleep & breathing = Schlaf & Atmung, 24(4), 1523–1529. https://doi.org/10.1007/s11325-020-02024-1
10. Lee, T. H., Yen, T. T., Chiu, N. Y., Chang, C. C., Hsu, W. Y., Chang, Y. J., & Chang, T. G. (2019). Depression is differently associated with sleep measurement in obstructive sleep apnea, restless leg syndrome and periodic limb movement disorder. Psychiatry research, 273, 37–41. https://doi.org/10.1016/j.psychres.2018.12.166
11. Hoshino, T., Sasanabe, R., Mano, M., Nomura, A., Kato, C., Sato, M., Imai, M., Murotani, K., Guilleminault, C., & Shiomi, T. (2019). Prevalence of Rapid Eye Movement-related Obstructive Sleep Apnea in Adult Narcolepsy. Internal medicine (Tokyo, Japan), 58(15), 2151–2157. https://doi.org/10.2169/internalmedicine.2601-18,
12. Smith, S., Sullivan, K., Hopkins, W., & Douglas, J. (2004). Frequency of insomnia report in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS). Sleep medicine, 5(5), 449–456. https://doi.org/10.1016/j.sleep.2004.03.005
13. Redline, S., Adams, N., Strauss, M. E., Roebuck, T., Winters, M., & Rosenberg, C. (1998). Improvement of mild sleep-disordered breathing with CPAP compared with conservative therapy. American journal of respiratory and critical care medicine, 157(3 Pt 1), 858–865. https://doi.org/10.1164/ajrccm.157.3.9709042
14. Cho, Y. W., Kim, K. T., Moon, H. J., Korostyshevskiy, V. R., Motamedi, G. K., & Yang, K. I. (2018). Comorbid Insomnia With Obstructive Sleep Apnea: Clinical Characteristics and Risk Factors. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 14(3), 409–417. https://doi.org/10.5664/jcsm.6988
15. Humer, E., Pieh, C., & Brandmayr, G. (2020). Metabolomics in Sleep, Insomnia and Sleep Apnea. International journal of molecular sciences, 21(19), 7244. https://doi.org/10.3390/ijms21197244
16. Dauvilliers, Y., Verbraecken, J., Partinen, M., Hedner, J., Saaresranta, T., Georgiev, O., Tiholov, R., Lecomte, I., Tamisier, R., Lévy, P., Scart-Gres, C., Lecomte, J. M., Schwartz, J. C., Pépin, J. L., & HAROSA II Study Group collaborators (2020). Pitolisant for Daytime Sleepiness in Patients with Obstructive Sleep Apnea Who Refuse Continuous Positive Airway Pressure Treatment. A Randomized Trial. American journal of respiratory and critical care medicine, 201(9), 1135–1145. https://doi.org/10.1164/rccm.201907-1284OC
17. Fang, H., Tu, S., Sheng, J., & Shao, A. (2019). Depression in sleep disturbance: A review on a bidirectional relationship, mechanisms and treatment. Journal of cellular and molecular medicine, 23(4), 2324–2332. https://doi.org/10.1111/jcmm.14170
18. Sateia M. J. (2014). International classification of sleep disorders-third edition: highlights and modifications. Chest, 146(5), 1387–1394. https://doi.org/10.1378/chest.14-0970
19. Chang, H. P., Chen, Y. F., & Du, J. K. (2020). Obstructive sleep apnea treatment in adults. The Kaohsiung journal of medical sciences, 36(1), 7–12. https://doi.org/10.1002/kjm2.12130
