Having heartburn at night also means that you’re at risk of stomach juices reaching your throat, which not only has acid, but bile, digestive enzymes, and bile. In light of the fact that about 10 to 25% of the population has at least some sleep apnea (the majority in the elderly in some studies), any pauses in breathing will literally suction up your stomach juices into your throat, causing not only arousals, but also swelling and inflammation, leading to post-nasal drip, chronic throat clearing, chronic cough, and even Eustachian tube dysfunction. 

The more often you stop breathing at night, the more you’re likely to suction up stomach juices into your throat, which can also lead to desensitization of your  pressure and sensory nerve endings. Over time, this can lead to loss of protective upper airway reflexes, predisposing one to obstructive sleep apnea. In addition, vibratory trauma from snoring is thought to not only desensitize sensory nerve endings, but also cause carotid artery wall thickening.

Not eating late will also increase your sleep efficiency, which can promote weight loss. On the contrary, any degree of sleep deprivation or sleep inefficiency will promote weight gain. Gaining weight promotes more reflux and sleep apnea.

Counseling New Yorkers to avoid eating (and drinking alcohol) within 3-4 hours of bedtime is the simple most important recommendation I make, in addition to my routine treatment options.

Instead, these symptoms are the beginnings of the most common throat problem sleep apnea sufferers face. And as I explain below, without understanding why this occurs, it can be one of the hardest problems to treat.

Beware of the “Vacuum Effect”

People with obstructive sleep apnea are more prone to breathing problems at night due to partial or total collapse of one or more areas of the entire upper airway, from the nose to the tongue. It’s usually worse when on your back, since the tongue can fall back more in this position. During deep sleep, your muscles naturally relax and you’ll be more susceptible to breathing stoppages.

Pressure sensors placed inside sleep apnea patients reveal that every time an apnea occurs, a tremendous vacuum effect is created inside the chest and throat, which literally suctions up your normal stomach juices into your esophagus and throat. This can happen occasionally, even for normal people, but if you happen to have a late meal or a snack just before bedtime, there will be even more stomach juices lingering in your stomach to come up into the throat. If you happened to drink a nightcap, the situation is even worse since alcohol is a strong muscle relaxant.

What comes up into your throat is not only acid, but also bile, digestive enzymes, and even bacteria. Washings of lung, sinus and ear contents have shown H. pylori, a common stomach bacteria, and pepsin, a major stomach digestive enzyme. So what comes up can cause severe irritation in your throat, provoking the mucous secreting glands of your throat to try to dilute these substances.

Although people generally attribute throat mucous to post-nasal drip, in most cases there’s nothing dripping down the back of the throat. It’s actually coming from your stomach. However, in some cases, since your stomach juices can reach your nose, it can cause nasal congestion and inflammation, which can aggravate tongue and soft palate collapse by creating a vacuum effect downstream. Ultimately, it’s a vicious cycle.

Chronic acid and other irritating substances lingering in your throat can have other detrimental effects. One recent study showed that chronic acid exposure can numb or deaden the protective chemoreceptors in your throat. These are sensors that detect any acid in the throat to prevent aspiration of your stomach contents into your lungs. If these chemoreceptors sense any acid in your throat, a feedback signal is sent to the brain, causing you to wake up so that you can swallow. This is what’s called a reflux arousal.

Treating Reflux For Good

So besides not eating late and avoiding alcohol close to bedtime, what else can you do?

I’m assuming that many of you that are reading this article are already being treated for obstructive sleep apnea, via either CPAP, oral appliances, or even with surgery. The problem is that no matter which option you choose, there will always be some degree of reflux. Taking acid reflux medications can help sometimes, but for the most part, these reflux medications don’t really do anything for reflux. All they do is to lower the acid content content before it comes up into your throat.

Other options include stimulating your stomach via natural remedies or prescription medications to empty your stomach much faster. One fascinating study showed that using a combination of pseudoephedrine (Sudafed) and a pro-motility agent (domperidone) eliminated snoring in most people. Unfortunately, we don’t have the equivalent of domperidone here in the US. Other similar medications are available, but have more serious side effects.

This is why eating early at least 3-4 hours of bedtime is so important whether or not you have obstructive sleep apnea. The same also applies to alcohol. If your nose is stuffy, talk with your doctor to find a way to breathe better through your nose. Make sure you’re sleeping in your preferred or optimal sleep position. Lastly, work with your sleep physician to fully optimize your sleep apnea treatment, no matter which option you choose.

We know that any form of breathing obstruction (apnea, hypopnea, RERA) can cause you to wake up. But what's not too commonly known is the fact that any degree of acid in the throat can stimulate certain chemical receptors, which causes you to wake up so you can swallow. It's thought that this is needed to prevent aspiration of stomach juices into your lungs. 

A recent Japanese study not only confirmed these concepts, but found an interesting additional observation: While people with severe obstructive sleep apnea have mostly arousals due to  breathing pauses, those with mild to moderate sleep apnea have a higher number of spontaneous arousals. Spontaneous arousals are noted on a sleep study when your brain waves go from deep sleep to light sleep or temporary awakening, without any objective evidence of breathing pauses.

What this study doesn't address is the fact that it's not only acid that comes up into the throat when you stop breathing. Your stomach juices also contain bile, digestive enzymes, and bacteria. An obstruction causes a tremendous vacuum effect that's created in the throat, literally suctioning up your normal stomach juices. This initial obstruction will lead to the typical respiratory arousal, but lingering juices will irritate the throat leading to spontaneous arousals. Think of your stomach juices as a sort of sensory form of stimulation, like a loud noise or a bright light. Your throat has a number of very sensitive chemical and pressure receptors that can cause your brain to wake up, without any physical obstruction.

There are also studies that show that chronic exposure to acid can make pressure sensors less sensitive over time, leading to longer and longer pauses with each obstruction.

Furthermore, there's research showing that some of these arousals don't ever show up on routine brain wave leads during a standard sleep study. This is because these protective reflex signals are so minimal that they stay in the deeper levels of the brain, never reaching the outer cortex.

I've always felt that spontaneous arousals are somehow related to breathing pauses. This study only confirms my suspicion that too many spontaneous arousals may be a sign of upper airway resistance syndrome or early obstructive sleep apnea. 

What's your opinion on this? Do you have laryngopharyngeal reflux disease?