Causes of Sleep Apnea

There are numerous causes of sleep apnea. Below are several physical characteristics and medical conditions that can help you identify your risk for sleep apnea.

Identifying Your Risk for Sleep Apnea

Sleep apnea is a sleep disorder in which your breathing stops and abruptly restarts repeatedly during sleep. Potentially serious, sleep apnea can be dangerous if left untreated, as its symptoms lead to a sharp decline in health and lifespan.

You may be at greater risk for sleep apnea depending on your age, gender, genetics, and lifestyle habits. Be aware of the risk factors so you can prevent sleep apnea or get it treated before it becomes a larger problem.

Signs You May Be At Risk for Sleep Apnea

The list of risk factors for sleep apnea is long. Even the most common symptoms or health conditions associated with sleep apnea are not well known outside of the medical community. This is changing, however.

Heightened interest in sleep and education around the sleep disorders that affect mood, general wellbeing, and how much energy people have to live happy, productive lives are creating more awareness around the issue.

With more conversations about the subject and information available, more people are discovering they’re at risk of suffering from sleep apnea; consequently, more people are seeking a diagnosis and treatment for this common sleep disorder. The result: a significant increase in quality of life and lifespan.

Although there has been an increase of awareness, there is still a long way to go before the general public realizes they’re at risk and should initiate a conversation with their doctor about sleep or seek answers directly from a certified sleep specialist.

Here is a list of the most common risk factors. This is not an exhaustive list, but if you’re suffering from any combination of these factors, one simple sleep test may be the key to unlocking better health and longer life.

Major Risk Factors for Obstructive Sleep Apnea (OSA)

Obesity

Excess weight can cause fat to accumulate around your upper airway, causing it to collapse during sleep and make breathing difficult. Obesity is generally defined as anyone with a Body Mass Index (BMI) >30. If your BMI is above 25, you are more at risk for sleep apnea; if your BMI is 30+, you are considered obese and your risk increases even more. Obesity rates are significantly higher in southeastern states.

By all measures, obesity has become an epidemic in recent years. Since 2000, the number of citizens with a BMI >40 has tripled. In 2018, the prevalence of obesity was 40.3% among men the ages of 20–39, 46.4% of men ages 40–59, and 42.2% of men 60 and over. The prevalence of obesity was 39.7% of women ages 20–39, 43.3% of women ages 40–59, and 43.3% of women 60 and over.² It’s estimated 50% of people with a BMI >40 have sleep apnea. Anyone with a BMI >40, especially if other symptoms or risk factors of OSA are identified, like snoring, should contact a sleep specialist for sleep apnea testing.

Male Sex

To date, there’s no nationally representative data on gender differences between men and women related to sleep apnea. There are more reported cases of sleep apnea in men, but conclusive studies laying out the exact reasons why men are more prone to sleep apnea haven’t been published.

Many experts suggest the actual number of women affected by OSA is much closer to the numbers of men affected by the sleep disorder, but they simply aren’t as likely to seek a diagnosis when compared to men.

Related: Women’s Risk for Sleep Apnea Increases During Menopause

Numerous studies looking at patients coming in for an evaluation for sleep apnea showed the ratio of men to women diagnosed with sleep apnea was lopsided. One woman is diagnosed with OSA for every eight to nine men. However, studies in the general population show a ratio of two to three men for every woman with OSA more closely resembles the actual disparity.

This discrepancy is in part due to how women describe their symptoms. Women generally describe their experience with non-specific symptoms like difficulty falling asleep, difficulty staying asleep, lack of energy, or general sleepiness. As a result, women are often misdiagnosed. The symptoms are not as specific to OSA or as obvious to a Primary Care Practitioner as snoring, gasping for air or choking while sleeping, or a thick neck circumference would be. Therefore, women are less likely to be referred to a sleep clinic for evaluation.

Despite the public perception of sleep apnea as a male issue, women can still be at risk and shouldn’t automatically assume that they don’t have sleep apnea. Men as a gender are in a higher-risk group and tend to suffer from more severe OSA than women. There are also a few physical traits that predispose them to the sleep disorder. However, women should be aware of the symptoms and risk factors for themselves as well.

Overweight Men Are More Likely Than Overweight Women to Have Sleep Apnea

As mentioned earlier, obesity is a common predictor of obstructive sleep apnea. A BMI > 30 for both men and women leads to a greater chance of suffering from a severe form of the disorder.

More women than men tend to have a BMI > 30, yet men’s weight is more highly correlated to sleep apnea than women’s weight. One explanation offered is the differences in fat distribution which may explain why more men than women are affected.

With weight gain, fat accumulates in the tongue, but women, in general, have lower Mallampati scores than men.³ A Mallampati score relates tongue size to pharyngeal size. It’s a simple test that’s also a good predictor of obstructive sleep apnea. Women’s lower scores suggest that fat does not play as large a role in the female tongue as it does in the male tongue. Men have bulkier tongues and soft palates and that contributes to more severe OSA as well.

Men’s Physical Characteristics May Contribute to Sleep Apnea

Another explanation for the difference in the number of men and women who have sleep apnea is that women have a shorter oropharynx. The oropharynx is the part of the pharynx that lies between the soft palate and the hyoid bone (this is the U-shaped bone in the neck that supports the tongue). The shorter the oropharynx, the smaller the section of upper airway is at risk for night time collapse. If this explanation is accurate, it may also explain why overweight men are more prone to OSA, because the fat has a shorter section of airway to adversely affect women than in men.

Advancing Age

Sleep apnea can occur at any age, although adults over the age of 40 are more likely to develop it. The Sleep Heart Health Study found that sleep-disordered breathing increased two to three times with age.⁴

Another study, with 427 male and female participants between 65 and 95 years of age, found that 70% of the men and 56% of the women had OSA (defined as more than 10 events — apneas or hypopneas — per hour).⁵

Additional studies demonstrated that both men and women between the ages of 65 and 100 were twice as likely as their middle-aged counterparts to have OSA.

If you’re over the age of 40, and exhibit other risk factors or are experiencing additional symptoms such as the medical conditions described below, a sleep test is a fast, easy and inexpensive way to ensure you’re not negatively impacted by this life-altering sleep disorder.

Snoring

Snoring is the sound of a blocked airway and of someone struggling to breathe. A blocked airway is indicative of obstructive sleep apnea (OSA). It can also be accompanied by a pause in breathing for brief periods of time that may cause choking or gasping for air.

Frequent airway blockages at night also put you at serious risk of long-term complications if untreated or treatment is delayed. Four out of ten people snore, and 80% of people who snore have obstructive sleep apnea (OSA).⁶ The other 20% of people who don’t have OSA but who snore are highly likely to get it within a few years. 

However, even if you DON’T snore, you could still be at risk. Not all people who have obstructive sleep apnea make noise, but snoring is the main symptom. All chronic snorers, especially when the snoring is frequent and loud, should be tested.

Medical Conditions as Risk Factors with Highest Prevalence of OSA

If you are experiencing any of the following medical conditions, a sleep test is advised. There is an extremely high prevalence of Obstructive Sleep Apnea (OSA) associated with these risk factors, ranging between 40% and 90%. There is also substantial evidence of improvement or risk reduction with PAP therapy.

Hypertension (High Blood Pressure)

Hypertension and obstructive sleep apnea (OSA) may appear to be very different from one another, yet they share common risk factors such as advancing age and obesity.

In addition to sharing these common risk factors, OSA is proven to release norepinephrine (adrenaline) throughout the night to arouse the body, thereby opening the closed airway and allowing oxygen in.

Norepinephrine is the most powerful agent known for raising blood pressure. This natural chemical is both a neurotransmitter and a stress hormone; when the brain perceives a threat, it releases Norepinephrine, triggering what is often called the fight-or-flight response. The continued release of Norepinephrine while sleeping is one of several reasons it’s so strongly related to this health condition.

In 2003 the Seventh Joint National Committee recognized OSA as a secondary cause of hypertension.⁷

The relationship between Hypertension and Obstructive Sleep Apnea

Both obstructive sleep apnea (OSA) and hypertension (HTN) are increasingly common health conditions that have coincided with rising obesity rates around the world. Overwhelming evidence also suggests both are on the rise, in part, due to a causal relationship between them.

If you have OSA, you’re predisposed to develop hypertension. The connection is so great between the two, it’s estimated between 30 and 70% of patients with OSA have hypertension.⁸ The more severe the sleep apnea is, the higher the prevalence.

If you’re hypertensive, there’s also a greater likelihood you’ll have OSA. It’s estimated between 20% and 40% of hypertensive individuals have OSA.⁹ Those numbers for hypertensive individuals, however, are considered an underestimate because of the significant underdiagnosis of obstructive sleep apnea globally.

Blood Pressure Medication Helps Control Blood Pressure, Not Eliminate Hypertension As a Risk Factor

Many hypertensive individuals mistakenly believe they don’t have high blood pressure when their hypertension is being controlled by medication. Controlling blood pressure through medication does not remove the connection to OSA or eliminate it as a risk factor. If you’re on medication for blood pressure, you are still considered hypertensive and should still get tested for sleep apnea to confirm or rule it out as a contributing factor.

Resistant Hypertension Has Highest Correlation to OSA

Sleep apnea testing is especially important if you’re having trouble controlling your hypertension. Resistant hypertension has the greatest association with OSA, with those suffering from it being 2.5 times more likely to have sleep apnea. The prevalence of OSA in resistant hypertension jumps drastically to 83%.¹⁰

Numerous studies have shown the strong association of OSA with cardiovascular morbidity and mortality. OSA and hypertension both require prompt diagnosis and treatment to help address the growing rate of cardiovascular disease and death caused by these two conditions.

If you or someone you know has hypertension, especially if they struggle to control their high blood pressure, a sleep apnea test is recommended right away.

ALL YOU NEED TO KNOW ABOUT SLEEP APNEA TESTING >

Stroke/TIA

Stroke is responsible for 1 out of every 20 deaths in the U.S. — or approximately 140,000 Americans — each year. It’s the leading cause of serious long-term disability and costs the U.S. approximately $34 billion each year, making it an important health issue to address.¹¹

Most strokes, about 87%, are ischemic strokes and occur when blood supply to the brain is reduced or interrupted as a result of a blockage.¹²

Hemorrhagic strokes occur when weakened blood vessels rupture. The most common cause of a hemorrhagic stroke is uncontrolled high blood pressure.

The relationship between stroke and obstructive sleep apnea

Untreated obstructive sleep apnea (OSA), which is also known as sleep-disordered breathing, is linked to multiple issues, including high blood pressure, atherosclerosis and arterial blockages, increased platelet adhesiveness, and vascular endothelial dysfunction. All of these issues can lead to both kinds of stroke.

One study demonstrated that sleep-disordered breathing precedes stroke and may also contribute to the development of stroke. Undiagnosed or untreated sleep apnea patients have a 60% increased risk of stroke or a transient ischemic attack (TIA), sometimes referred to as a mini-stroke.

A cross-sectional and longitudinal analysis of the Wisconsin Sleep Cohort Study also found 69-77% of people who had a stroke also had OSA. They also observed that when sleep-disordered breathing is present after a stroke, post-stroke rehabilitation takes longer, an individual’s functional capacity is worse, and it also leads to a higher death rate.¹³

If you’re at risk for a stroke or have had a stroke, these findings support getting a sleep apnea test to rule out OSA as a contributing factor.

SCHEDULE A CONSULT FOR SLEEP APNEA TESTING >

Coronary Artery Disease

It’s challenging to prove that OSA can independently cause coronary artery disease because it shares common risk factors such as obesity, smoking, age, hypertension, and diabetes.¹⁴ However, a growing body of research addresses OSA’s role and connection to the disease. One study from 2018 found CPAP therapy (the most common treatment for OSA) led to a 28% decrease in the risk of developing coronary artery disease, underscoring the strong connection between the two.¹⁵

Nearly one-third of women and half of the male population over the age of 40 will experience coronary artery disease.¹⁶ Many factors contribute to this, including inflammation and oxidation stress. Oxidative stress leads to endothelial damage and plaque build-up.

With obstructive sleep apnea, the repeated oxygen deficiency and reoxygenation during sleep increases oxidative stress, leading to vascular damage. This is just one reason the two are linked. It’s also been shown that CPAP treatment for OSA has demonstrated a reversal of the vascular damage caused by this disorder, further highlighting a causal link — while also being a strong indicator a sleep test is needed.

Pre-Diabetes, Diabetes Type 2

The link between obstructive sleep apnea (OSA) and both type 2 diabetes and pre-diabetes is so strong that if you have either and have a BMI > 30, there’s an 86% chance you have obstructive sleep apnea.¹⁷

The strong link between the two is related to norepinephrine. Norepinephrine, as mentioned above, is best known as a stress hormone and a main component of the fight-or-flight response. It also raises blood sugar. When you have untreated or undiagnosed obstructive sleep apnea, you’re releasing norepinephrine throughout the night in response to airway blockages.

If you’re pre-diabetic or already have type 2 diabetes, especially if you exhibit any other symptoms such as snoring, it’s imperative you take a sleep test to determine if OSA is contributing to the condition. If you are diagnosed with sleep apnea, its treatment will also help improve your ability to control your body’s insulin response because OSA makes the treatment of diabetes more difficult.

Chronic Obstructive Pulmonary Disease (COPD)

Together, COPD and sleep apnea are called overlap syndrome. Each one worsens the other, and together they can lead to longer-term chronic health problems unrelated to the lungs, such as pulmonary hypertension and diabetes.

It’s highly recommended that anyone struggling with COPD should be tested for sleep apnea. One reason for this is because when dealing with both COPD and obstructive sleep apnea, the compromised respiratory system can’t rely on sleeping at night for recovery or relief; as a result, oxygen desaturation in the body is significantly worse. Where occasional occurrences of sleep apnea may result in 3% to 4% blood oxygen desaturation in a normal lung, it can cause 15% to 20% blood oxygen desaturation in the lungs of someone with COPD.¹⁸

This is why it’s important to discuss your situation with a sleep specialist to determine whether obstructive sleep apnea could be aggravating your symptoms or contributing to health risks and serious complications.

Excessive Daytime Sleepiness (EDS)

Excessive daytime sleepiness (EDS) is commonly caused by sleep apnea. Despite the occasional feelings of exhaustion or fatigue many experience as a result of not getting enough sleep, EDS is persistent exhaustion during the day despite the number of hours slept.

EDS is one of the most common problems reported by people visiting a sleep clinic, with nearly 20% of people in the US experiencing it, according to the National Sleep Foundation. Although it isn’t a disorder itself, it is a symptom of more serious conditions interfering with sleep such as obstructive sleep apnea.

If you’re experiencing excessive daytime sleepiness, you understand the toll it takes on your everyday life. That’s why it’s important to find the underlying cause.

The sleep fragmentation that occurs with sleep-disordered breathing (sleep apnea) at night often leads to EDS because deep restful sleep doesn’t occur.

When you speak with a sleep specialist, they’ll gather information about your medical history, ask whether you’re exhibiting other signs of sleep apnea such as snoring, and will recommend either a in-home sleep apnea test or a sleep study to diagnose whether sleep apnea is the root cause of your excessive daytime sleepiness.

If sleep apnea is diagnosed, CPAP treatment to keep your airway open at night and allow for deep restorative sleep to occur will be discussed along with potential lifestyle changes such as weight loss and eating healthy.

Erectile Dysfunction (ED)

Many don’t realize there is a direct correlation between obstructive sleep apnea (OSA) and erectile dysfunction. If you’re experiencing difficulty achieving or sustaining penile erections, untreated or undiagnosed sleep apnea may be the cause or a major contributing factor.
This may occur for years before a man completely loses the ability to get an erection.

A man’s ability to maintain firm erections is one of the best indicators of cardiovascular health. The reason for this is because the penis is full of vascular tissue. When aroused, blood rushes to the tissue. If blood is unable to get to the tissue or stay in the tissue, it hints at a much larger problem, such as coronary artery disease.

Sleep apnea, heart and artery issues, and erectile dysfunction are closely linked. Common reasons men struggle with ED include high blood pressure and diabetes. OSA contributes to and worsens cardiovascular conditions like high blood pressure and coronary artery disease, in addition to type 2 diabetes. If you’re affected by any of these conditions and are struggling with erectile dysfunction, seeking sleep apnea testing is a good place to start.

In some instances, the medications you may use to treat ED will relax certain types of muscles in the body. One muscle group potentially affected is located around the upper airway (or throat) area. When the muscles around your upper airway relax, it can increase its propensity to collapse, thereby causing an obstruction (or apnea). Therefore, not only can these medications contribute to or cause OSA, but they can worsen it as well.

If you’re experiencing erectile dysfunction (ED), notify your men’s health physician or a sleep specialist. Proper treatment of sleep apnea, if related, can help alleviate the symptom. With existing in home sleep apnea testing technology, it’s fast, convenient and easy to find out if sleep apnea is preventing satisfying sexual encounters with your partner.

Treatment of sleep apnea has proven effective for ED as well, with multiple studies finding that CPAP therapy, the most common treatment for sleep apnea, helps treat both coronary artery disease and ED.

Cognitive Impairment

Cognitive functioning includes the mental processes of memory, perception, reasoning, and judgment. All of these cognitive functions are impacted by obstructive sleep apnea (OSA). In fact, cognitive impairment is identified as a common result of obstructive sleep apnea. People diagnosed with the sleep disorder are 7.5 to 20 times more likely to struggle with concentration or learning new tasks.¹⁹

Cognitive processing and memory are also affected by OSA. This leads to a decreased ability to understand, store, retain, and recall information. A recent study found people with untreated sleep apnea have difficulty recalling details about their own lives. These memory gaps often lead to depression.²⁰

Any disruption in sleep patterns negatively impacts the brain’s ability to replace neurochemicals, like serotonin, during deep sleep. These neurochemicals are largely responsible for cognitive function. Neurochemical deficiency resulting from sleep disruption caused by obstructive sleep apnea results in memory problems and other cognitive impairments.

Another reason cited for these memory gaps is fragmented sleeping patterns. Good sleep is required for the consolidation of autobiographical memories, which is something people with untreated OSA don’t get. Brain scans also show a significant loss of grey matter in the areas of the brain that overlap with the autobiographic memory network.²¹

Executive functioning is another area affected by sleep-disordered breathing. Executive functioning includes self-control, flexible thinking, and working memory. Without executive functioning organization, focus, follow-through, and regulating emotions are difficult to perform.

There is hope, however. People who suffer from memory problems as part of their sleep disorder often report a substantial improvement in memory once their sleep disorder is treated. One study found executive functioning improved after just three months of CPAP treatment.

LEARN MORE ABOUT CPAP TREATMENT FOR SLEEP APNEA >

Nocturia/Enuresis

Nocturia (nighttime urination) is a common screening question for sleep apnea patients. Unlike snoring or choking and gasping for air during the night, it’s easy for people to self identify as exhibiting the symptom.

Many people believe frequent urination during the night is a result of old age or in the case of men, the prostate. Although this may be the case, it’s also a strong indication of obstructive sleep apnea.

Over 84% of patients with sleep apnea reported frequent nighttime urination, with as many as 6 or more nighttime trips to the bathroom reported by those suffering from the sleep disorder.²²

Research also suggests nocturia as a symptom of sleep apnea might be even more common in women than in men.²³

Several studies have demonstrated that the treatment of sleep apnea improves nocturia caused by the sleep disorder. In one study, subjects who were resistant to conventional therapy reduced the frequency of nocturnal urination with CPAP treatment.²⁴

Additional Common Risk Factors for Obstructive Sleep Apnea

As you can see, there are numerous risk factors to consider when assessing your need for sleep apnea testing. Some symptoms and risk factors listed above are extremely common, while others listed below demonstrate an increased likelihood of having OSA. These risk factors when combined with factors above, are a strong indication a test or sleep study should be performed.

Genetics and family history

You are more likely to develop sleep apnea if members of your family snore or suffer from it as well. Some of the inherited traits that increase the risk of sleep apnea include obesity and specific physical features, like a recessed jaw and thick neck.

Thicker necks often lead to smaller airways, which can make you more susceptible to developing sleep apnea. A large neck has more soft tissue, and this can block the airway during sleep. For men, a neck size of 17+ inches puts them at higher risk. For women, a neck size of 16+ inches increases their risk.

Menopause

Although women are less likely to have sleep apnea, the probability of developing it goes up after menopause, as the change in hormones can affect your breathing.

Between half and 2/3rds of post-menopausal women have sleep apnea.²⁵ One reason for this is that during menopause estrogen levels are lower. Estrogen helps keep muscles firm and supple, including throat muscles. So when estrogen levels decline, women are much more likely to develop sleep apnea.

Women during menopause are also more likely to gain weight, and additional weight on the neck can press down on the airway at night and increase the likelihood of sleep apnea.

Smoking

Smoking can inflame the upper airways, making breathing more difficult. Smokers are more likely to develop sleep apnea than non-smokers — almost three times more likely, in fact.

Alcohol Consumption

Alcohol relaxes your airway muscles, which can cause upper airway collapse and lead to more snoring. It also makes your breathing slower and more shallow. Heavy drinking can cause frequent sleep apnea episodes and put you at risk for the disorder.

Use of sedatives or tranquilizers

Some medications make sleep apnea worse. If diagnosed with sleep apnea, discuss any medications you’re currently taking with your sleep specialist to make sure they aren’t worsening your apnea. Certain medications like sedatives can relax the upper airway muscles and lead to more snoring and sleep apnea.

How to Prevent Sleep Apnea

Preventing sleep apnea typically means treating sleep apnea to prevent obstruction. For milder cases of sleep apnea, eliminating or removing factors that are known to increase sleep-disordered breathing can help.

Drinking alcohol and smoking are two behaviors to limit or avoid entirely, since doing so may prevent mild sleep apnea. Losing weight can help prevent sleep apnea when excess weight is responsible for the breathing interruptions.

Obesity is a major risk factor as mentioned earlier, especially with a BMI greater than 40. If you fall into this category, losing weight may be an effective way to prevent sleep apnea. However, it’s important to consider that, many times, weight loss alone won’t eliminate sleep apnea if other health conditions or risk factors are involved, such as heredity, menopause for women, or advanced age.

Consult with your sleep doctor to monitor your condition closely and determine if adjustments to treatment are possible, and determine whether milder cases of sleep apnea are involved.

As discussed in-depth above, many risk factors related to sleep apnea range from genetics to age, gender to weight and include many common health conditions.

Prevention of sleep apnea is not possible by addressing many of these risk factors. For example, heredity and being male isn’t something you can change.

Yet it’s still possible to help improve your health and reduce the impact sleep apnea has by adjusting your habits, making lifestyle changes, and getting tested if you’re at risk.

Ways to Help Avoid or Reduce the Impact of Sleep Apnea

• Maintain a healthy weight
• Reduce your drinking, especially in the hours before bedtime
• Stop smoking
• Don’t take sleeping pills or sedatives before bed

The above actions will help decrease the severity of sleep apnea, but treating the disorder is the best way to reduce the health risks associated with OSA and prevent the obstructions from disrupting your sleep.

Make sure you don’t have sleep apnea by getting tested.

Sleep Centers of Middle Tennessee serves the entire state of Tennessee with its integrated sleep medicine OSAinHomeSM program and is your best resource on sleep apnea and getting better sleep for better health.