Common Sleep Apnea Comorbidities
While researchers are looking further into causal relationships between sleep apnea and other comorbid conditions, it is important to understand that these relationships do exist and can cause multiple health problems if left untreated. Many conditions associated with sleep apnea are also related to weight and obesity, such as diabetes, hypertension, and cardiovascular disease. Other sleep disorders like insomnia are very common as well. In addition, some mental problems have been positively correlated with sleep apnea syndromes, for example, depression can result from the fragmented sleep patterns caused by apnea events. While a sleep apnea diagnosis does not guarantee that other health or mental problems will arise, the likelihood of developing other conditions is high, particularly if the disorder goes untreated for long. As a result, doctors will often treat sleep apnea with comprehensive care, not only prescribing treatments such as PAP therapy, but also recommending lifestyle changes to improve overall health.
Obesity and Metabolism
One of the first concerns for many people with sleep apnea is weight. A large majority of sleep apnea patients have a body-mass index (BMI) of 25 or higher (overweight or obese). This means that metabolic difficulties such as diabetes or pre-diabetes are very likely to develop as comorbid conditions. One study found that in more severe obesity (BMI above 40 kg/m2), the prevalence of sleep apnea was as high as 90 percent in some sample populations. Sleep apnea, or obstructive sleep apnea (OSA) in particular, is very closely related to weight, as the mechanism of blockage is driven by fat content in the tongue and upper airway. The combined effects of respiratory blockage and sleep disruption make it difficult for the body to maintain a healthy metabolic rate, leading some researchers to suggest that sleep apnea could be a manifestation of metabolic syndrome, a condition that often coincides with rapid or sustained weight gain. Along with diabetes and other metabolic problems, a study published in the journal Sleep and Breathing lists congestive heart failure, deep vein thrombosis, pulmonary embolism, hypothyroidism, inflammatory disorders, and chronic obstructive pulmonary disease, or COPD, as common comorbid developments in sleep apnea patients with weight problems. The study observed the effects of advanced metabolic syndromes over time, finding most patients with these conditions (over 60 percent) were not adherent to their PAP-therapy treatments, and most deaths occurred at night, regardless of the cause. These are sobering examples of how sleep apnea, when left untreated, can exacerbate other health problems, whether they are a cause of the disorder or a symptom.
When there are multiple health problems related to sleep apnea, providers will often recommend additional treatments and lifestyle changes to go along with CPAP. These more comprehensive approaches, especially weight-loss interventions, have shown great promise in cases where weight is a primary concern, leading to reductions in sleep apnea symptoms as well as their cardiometabolic counterparts. For example, pre-diabetic conditions have been reduced and controlled with a combination of PAP therapy, diet, and exercise. In the long term, these changes can lead to great improvements in overall health and quality of life, while the absence of treatment increases the risk for more serious complications such as cardiovascular disease, ultimately leading to early mortality.
Heart Health, Cardiovascular Disease, and Stroke
In many cases, weight issues will also include cardiovascular problems, especially without regular treatment. Even without sleep apnea, these are serious health concerns, but along with a sleep apnea condition, there is a much higher rate of congestive heart failure, coronary artery disease, and stroke. The cardiovascular system depends on healthy blood pressure levels to pump oxygen to the organs and extremities. If sleep apnea is left untreated for long, oxygen levels in the blood can diminish (hypoxia), while at the same time the effects of hypertension, or high blood pressure, will actually reduce arterial vasodilation and impair oxygen delivery. This systemic condition can very easily lead to stroke, either from a blocked artery (ischemic stroke) or the bursting of a blood vessel (hemorrhagic stroke). It should also be noted that some researchers speculate that the link between sleep apnea and high cancer mortality may be a result of low oxygen from obstructed breathing. Tumor development is supported through a process called neovascularization, which is carried out in the blood vessels and helps the cancer cells expand and metastasize.
When it comes to heart and cardiovascular health, sleep apnea can sometimes become a marginal concern, but the effects of untreated apneas should never be underestimated. Sleep and respiratory health are closely related to the heart and circulatory system, which depend on proper oxygen levels to function. Fragmented sleep cycles further complicate the issue by keeping the body from maintaining its natural state of homeostasis, forcing the heart and arteries to work overtime to make up for periodic losses during the night. Almost every process in the body is related in some way to the heart and blood oxygen. This is why systemic problems like sleep apnea are best treated by first stopping the apneas, and then by addressing underlying health problems that may have played a role in in its initial development.
While PAP therapy will reduce or eliminate the symptoms of sleep apnea, other sleep problems may still keep patients from achieving quality sleep on a regular basis. Whether additional sleep disorders develop as a result of sleep apnea or simultaneously, the result is often the same; chronic sleep problems develop. In these cases patients will often require multiple treatments. For example, a patient may have insomnia as well as sleep apnea. The insomnia may be a separate condition, or it may develop as a result of the fragmented sleep caused by apnea events. Other sleep disorders, such as hypersomnolence, sleep-related movement disorders, and parasomnias, have also been linked to sleep apnea. When these conditions develop, other treatments such as medication may be needed to help patients fall asleep and stay asleep during PAP therapy. Other treatments such as sleep restriction or cognitive behavioral therapy (CBT) are sometimes used to help patients establish healthy sleep habits that coincide with their natural circadian rhythms. These treatments, when used alongside CPAP, can not only benefit sleep health but also reduce the risk of developing further sleep problems in the long term.
Mood Disorders and Other Related Conditions
In addition to the physical ailments that develop alongside sleep apnea, mood disorders and psychological conditions may also create problems of their own, making it even more difficult to maintain a healthy lifestyle. This can be related to sleep apnea in a variety of ways and can be very difficult to treat, especially when other comorbid conditions are involved. Depression, the most commonly associated psychological condition among sleep apnea patients, is often related to weight and low energy (daytime sleepiness). This is far more common with untreated sleep apnea, but may also affect those who use CPAP regularly. Every patient is unique in this respect, and each will have his or her own personal experiences that can affect them in different ways. In such cases, the guidance of a therapist, clinical psychologist, or psychiatrist can help patients identify problem areas and determine the best course of action for further care. When dealing with more than one condition, professional help is absolutely essential. Comorbid relationships can be complicated, and the advice of a specialist for each area of concern is the best route for comprehensive care. Of course, this may require more visits to the clinic, but it will also ensure that the best possible treatment options are available.
Frontiers in Endocrinology – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6282065/
Frontiers in Psychology – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6042013/
Hippokratia – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2464309/
International Review of Psychiatry –https://pubmed.ncbi.nlm.nih.gov/16194800/
Journal of Chiropractic Medicine – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110415/
Journal of Clinical Sleep Medicine – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2546461/
Journal of Physiology – https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/JP275545
Multidisciplinary Respiratory Medicine – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609382/
Proceedings of the American Thoracic Society – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2645252/
Sleep and Breathing – https://pubmed.ncbi.nlm.nih.gov/30685854/
Sleep Medicine and Disorders – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6340906/
Sleep Medicine Reviews – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006997/