Is Your MS Fatigue Caused by Hidden Sleep Apnea?

The research highlighted in a 2019 poster by the American Academy of Neurology arrived at a conclusion that might surprise many of us living with multiple sclerosis (MS):¹

• Undiagnosed obstructive sleep apnea (OSA) is common in people with MS who report fatigue
• Rates of OSA in people with MS appear to increase with age
• OSA rates in people with MS increase with higher scores on the expanded disability status scale (EDSS) but are still common in those with low EDSS scores
• OSA is more common in people with a high body mass index (BMI), but people with a low BMI may still have OSA.
• Accurate identification of specific causes of fatigue in people with MS might improve treatment outcomes.

This research means that if you have extreme daytime fatigue or sleepiness, MS may not be entirely to blame.

Sleep apnea is common in people with MS

While experts aren't exactly sure why, people with MS are at a higher risk for both OSA and central sleep apnea (CSA) than people without MS. Research shows that up to 50 percent of people with MS may have OSA. People with MS may be at a higher risk for sleep apnea because of changes in brainstem function caused by MS. The brainstem controls muscles that keep the airway open when we sleep. It also controls breathing when we are not awake. MS can cause lesions to form in the brainstem, disrupting the pathways that control upper airway muscles and breathing.²

Sleep apnea has major impacts

Sleep apnea can impact day-to-day life. People who have untreated OSA may not be able to perform their jobs, operate machines, or make critical judgments and decisions while at work. They may also suffer from other comorbid conditions caused by untreated OSA. These include mood disorders, heart problems, or metabolic conditions like diabetes or kidney disease, among others.³

Also, one study found that people with untreated sleep apnea are nearly 2.5 times more likely to experience a motor vehicle accident. When treated, they reduce their risk of crashes by 70 percent.⁴

Body-mass index as a factor in sleep apnea

Having MS may mean dealing with physical limitations that make a sedentary lifestyle more likely. One of the problems of sedentary living for anyone of any age is the likelihood of weight gain and obesity. Both can create the right conditions for developing OSA. Aging may also bring unwanted weight gain, especially for women following menopause.³

Another factor for women with MS may be pregnancy. With the added water weight gain that comes with pregnancy, the odds increase for developing snoring, upper airway resistance, and full-blown sleep apnea. Up to 20 percent of pregnant women develop sleep apnea.⁵

Age as a factor in sleep apnea

Sleep apnea also becomes a bigger problem as we age, regardless of our general health status. This is due to the loss of tone in the muscles that control the upper airway. This makes them more likely to collapse during sleep.³

Catch sleep apnea in the act!

If you’re concerned about daytime fatigue, you may consider visiting your doctor and requesting a sleep study to rule out a sleep disorder. Ask your MS specialist about this. Many primary care doctors don’t even ask about sleep health. An MS specialist will be more inclined to follow through on a referral if you complain of both sleep problems and daytime fatigue or sleepiness (which can be hard to differentiate).

You may undergo a simple screening or a lightweight home test, depending on your insurance requirements. However, you might also be asked to take part in a nocturnal polysomnogram (NPSG) at a sleep clinic. Most overnight tests are comprehensive and will catch OSA in the act.³

Here's a tip: If a loved one complains that you snore loudly or gasp in your sleep, and you find yourself waking up several times a night for no apparent reason, these are good signs that you might need to be screened for this stealthy sleep disorder. Treating sleep apnea is not only possible but can be effective for treating other problems. Lowering blood pressure, reducing blood-sugar elevations at night (for those with metabolic conditions), elevating mood, and supplying more daytime energy are some of the benefits of treating OSA.³

Remember, not every symptom is caused by MS. Fatigue may be the result of a hidden concern like sleep apnea. Fortunately, OSA is treatable.