Study Links Aerophagia and GERD for CPAP Users

[-SWS]

Aerophagia and Gastroesophageal Reflux Disease in Patients using Continuous Positive Airway Pressure: A Preliminary Observation

Study Objectives:
Aerophagia is a complication of continuous positive airway pressure (CPAP) therapy for sleep disordered breathing (SDB), whereupon air is forced into the stomach and bowel. Associated discomfort can result in CPAP discontinuation. We hypothesize that aerophagia is associated with gastroesophageal reflux disease (GERD) via mechanisms involving GERD related lower esophageal sphincter (LES) compromise.

Methods:
Twenty-two subjects with aerophagia and 22 controls, matched for age, gender, and body mass index, who were being treated with CPAP for SDB were compared in regard to clinical aspects of GERD, GERD associated habits, SDB severity as measured by polysomnography, and mean CPAP pressure.

Results:
More subjects with aerophagia had symptoms of GERD (77.3% vs. 36.4%; p < 0.01) and were on GERD related medications (45.5% vs. 18.2%, p < 0.05) than controls. Regarding polysomnography, mean oxygen saturation percentages were lower in the aerophagia group than controls (95.0% vs. 96.5%, p < 0.05). No other differences were observed, including mean CPAP pressures. No one in the aerophagia group (vs. 27.3% of the control group) was a current tobacco user (p < 0.01). There was no difference in caffeine or alcohol use between the 2 groups.

Conclusions:
These results imply aerophagia is associated with GERD symptoms and GERD related medication use. This finding suggests a relationship between GERD related LES pathophysiology and the development of aerophagia in patients with SDB treated with CPAP.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576329/

Robysue are you reading? LoQ too...

[robysue]

One potential problem with this study is that correlation and causation are not the same. And which comes first? Is it possible that CPAP might CAUSE GERD to develop in some subset of the population rather than simply aggravate an already existing condition? And then there is the intriguing fact that approximately 1/3 of the aerophagia-plagued CPAPers apparently did NOT have a clinical diagnosis of GERD. Presumably their aerophagia stemmed from something else? Statistically speaking that's a pretty large subset of the folks plagued by the undesirable side-effect.

I mention these things not merely because I've never been diagnosed with GERD, but also because my husband has been diagnosed with GERD and I really and truly don't believe that I had GERD prior to last September---if I now have indeed have it. So I will admit GERD could indeed be my problem. And indeed if areophagia continues to plague me or if I develop any actual symptoms of GERD, I follow up on it. But right now, the switch to BiPAP has largely resolved the aerophagia issues (knock on wood).

Of course my bigger problem right now is the insomnia monster: He is now raging out-of-control in my bedroom, having grabbed hold of the fact that the PR S1 makes more noise than the S9 and is now screaming through the night with with that fact like an out-of-control banshee. But that's another story that's OT for this thread, and at this point I believe strongly that the insomnia monster is the the beast that I must deal with since he's is the one who is actively working to undermine my adjustment to the BiPAP. Progress, however, is being made in stalking the beast and restoring some peace to the bedroom.

[-SWS]

One potential problem with this study is that correlation and causation are not the same. And which comes first?

The authors present a strong correlation between aerophagia and GERD in cpap users. They then present conjecture about causation of both: LES related pathology linking GERD and CPAP-related aerophagia. Also, there's an interesting commentary titled "CPAP and Things That Go “Burp” in the Night" in which transient LES relaxation and treatments are discussed.

Is it possible that CPAP might CAUSE GERD to develop in some subset of the population rather than simply aggravate an already existing condition?

I suspect that's true in this anecdotal patient subset we discussed previously:

Robysue, you might also consider the possibility of nearly asymptomatic acid reflux disease. Most people fare BETTER with acid reflux issues once they go on CPAP. However, over the years we have had more than a few patients mention acid reflux disease onset that was seemingly triggered by CPAP. Anecdotally, I think those are patients who claim at least some CPAP related aerophagia tendencies as well. Fluid dynamics in the upper GI tract are, after all, a two-way phenomenon.

And then there is the intriguing fact that approximately 1/3 of the aerophagia-plagued CPAPers apparently did NOT have a clinical diagnosis of GERD. Presumably their aerophagia stemmed from something else? Statistically speaking that's a pretty large subset of the folks plagued by the undesirable side-effect.

In the CPAP study group, 77.3% of aerophagia-plagued CPAPers had GERD symptoms while 22.7% did not; in the non-CPAP control group 36.4% of aerophagia sufferers had GERD symptoms while 63.6% did not. Will you please double check that statistic in red to see if I interpreted it correctly?

Anyway, if you're an aerophagia-plagued CPAP'er then you have MORE than 3/4 of a chance of being SYMPTOMATIC of GERD. Guess what, robysue? I have GERD and I'm not even in that 77.3%. I'm not asymptomatic of my aerophagia episodes, but I am asymptomatic of my GERD. That means as a CPAP-using study subject I would have fallen in the 22.7% group who did NOT present GERD symptoms. How's that for interesting food for thought...

Ozij recently mentioned this conjecture, which I thought was worth additional discussion:

Your hypopneas with arousal seen in the sleep study are a result of GERD - which has recently been identified as a cause of insomnia, arousals, irritation of the nasal mucosa and back of throat. People with a weaked lower esophagal sphincter will have more acid reflux -- and more aerophagia.

So you have a sub-clinical AHI, but a high and unacceptable arousal rate. Robysue, I'm actually thinking there's a chance that silent acid reflux disease is your sleep disordered breathing problem and NOT ordinary apnea/hypopnea syndrome. If so, CPAP might not make treatment sense in your case.

[avi123]

Aerophagia and Gastroesophageal Reflux Disease in Patients using Continuous Positive Airway Pressure: A Preliminary Observation

These results imply aerophagia is associated with GERD symptoms and GERD related medication use. This finding suggests a relationship between GERD related LES pathophysiology and the development of aerophagia in patients with SDB treated with CPAP.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576329/

Robysue are you reading? LoQ too...

************************
I would be more interested in the reverse: if those who already have GERDs would be more susceptible to increased aerophagia. But, regardless of the aerophagia, GERD should be checked by an upper endoscopy test to see if a Barrett Esophagus syndrome has developed.

More posts on it:

http://www.apneasupport.org/about20822.html

[-SWS]

Thanks for sharing that link, avi123.

I would be more interested in the reverse: if those who already have GERDs would be more susceptible to increased aerophagia.

I agree the reverse would be useful. Why do you consider the reverse to be more interesting/useful?

[avi123]

Thanks for sharing that link, avi123.

I would be more interested in the reverse: if those who already have GERDs would be more susceptible to increased aerophagia.

I agree the reverse would be useful. Why do you consider the reverse to be more interesting/useful?

I think that I got my answer in this report which reviews the OP:

Link:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576330/

Excerpt:

"It is presumed that those with GERD have greater susceptibility to aerophagia due to a lower threshold of induction of transient relaxations of the LES secondary to gastric distention occurring via the CPAP treatment. Although very plausible on the surface, this speculation has several drawbacks. First, it makes the assumption that the aerophagia is of the “gastric” type noted above and there is no evidence that CPAP, no matter the pressure, results in substantial amounts of air in the stomach. In point of fact, if this is an issue of air in the stomach, it would seem that the symptom of aerophagia would be more prevalent in patients with higher CPAP pressures. The authors present no data that this is the case. More likely in fact, is that the air would expand the esophagus, but it seems obvious that this could not result in symptoms the subsequent day since there is no way the air could be retained in the esophagus. Furthermore, it is not clear how the relatively small amount of pharyngeal positive pressure noted in these data (approximately 10 cm H2O) could breech the upper esophageal sphincter whose pressure is commonly in the range of 100 mm Hg. Also, as noted above, belching and abdominal bloating are common complaints among GERD patients, and one could speculate that the “aerophagia” in the CPAP patients with GERD may simply be a manifestation of their GERD. This is quite plausible since the aerophagia patients were identified as anyone who had “…painful abdominal bloating, eructation, or flatulence related to CPAP treatment…”


SWS, notice the underlined which says that those with GERDs are aerophagic to begin with.

More: How does GERD affect sleep?

Of heartburn sufferers, a large majority experiences it at night. Our research indicates that nighttime GERD is a significant contributor to sleep problems. We've discovered that acid contact with the esophagus at night can prevent or delay the onset of sleep. Moreover, once asleep, the sleep is fragmented.

See it here:

http://www.sleepfoundation.org/article/ ... sease-gerd

[ozij]

It is clear to me that the person who wrote the commentary never experienced the major gastric distention and pain caused by CPAP insufflation - and probably never met patients who experienced that.

There is a lot of evidence that for some people, CPAP insufflates the abdominal tract with painful amounts of air, and it is worse when the pressure is higher.

There is also research evidence of the realtion between insomnia /interrupted sleep and GER.
http://www.springerlink.com/content/36847775294rn646/
Digestive Diseases and Sciences
Volume 53, Number 6, 1493-1499, DOI: 10.1007/s10620-007-0057-1

Conclusions Despite the lack of GERD symptoms, a significant minority of subjects with sleep disturbance have abnormal acid exposures. These preliminary data suggest that aggressive treatment of GERD in such patients may result in improvement in sleep efficiency.

http://www.medscape.com/viewarticle/710110
Gastroesophageal Reflux and Insomnia
Kurt J. Isselbacher

Posted: 10/07/2009; AccessMedicine from McGraw-Hill © 2009 The McGraw-Hill Companies

Gastroesophageal reflux (GER) has many consequences throughout the 24-h period during both wakefulness and sleep. Over the long term, sleep-related GER is associated with long reflux episodes (>5 min), higher esophagitis grades, Barrett’s esophagus, and esophageal adenocarcinoma. Sleep-related GER ulcers cause esophageal symptoms in 75% of subjects. A systematic review of five population-based studies shows that sleep-related GER is associated with poor sleep quality, arousals from sleep, fatigue, and impaired work productivity (Harding, 2009). Several studies have shown that proton pump inhibitors improve sleep quality, reduce lost work hours, and increase productivity in patients with GER.

It is important to point out that sleep-related GER causes insomnia. Patients may not realize that GER is contributing to their insomnia. Similarly, when patients complain of their insomnia, physicians may not appreciate that GER is a contributing factor; as a result, instead of intensifying GER therapy they may prescribe nonbenzodiazepine hypnotics such as zolpidem. This hypnotic, in fact, prolongs esophageal acid clearance and delays the arousal response; this can further worsen reflux and thus worsen insomnia. Therefore, it is important for physicians to consider that sleep-related GER is a possible cause of insomnia.

[-SWS]

I think that I got my answer in this report which reviews the OP:

Excerpt:
... one could speculate that the “aerophagia” in the CPAP patients with GERD may simply be a manifestation of their GERD. This is quite plausible since the aerophagia patients were identified as anyone who had “…painful abdominal bloating, eructation, or flatulence related to CPAP treatment…”

SWS, notice the underlined which says that those with GERDs are aerophagic to begin with.

No offense, AVI123, but the words I have in red make me disinclined to read that author's professed speculation as answer or fact. However, I can go along with the idea the author has raised some compelling questions.

Also, thank you very much for the other links you provided, AVI123.

[Janknitz]

Definitely more study needed.

Personally I had pretty bad GERD before I ever started CPAP (for many years) and I have NO reflux on CPAP (but have it immediately if I dare to fall asleep without my machine). I know that other people don't experience symptoms of GERD until they begin using CPAP.

I do have some degree of aerophagia on CPAP, but it's extremely mild, especially after I learned the trick of sleeping with my tongue on the roof of my mouth. So I don't think it's issue of my LES at all. It looks to me like they need to do a lot more carefully focused studies before drawing ANY conclusions about a link between aerophagia and GERD. Such studies would also have to rule out "silent GERD" in people who may have had GERD before CPAP without realizing it.

[SleepingUgly]

Don't forget about the study that showed CPAP helps GERD, even in the absence of OSA (I can't imagine that anyone other than a paid subject would want to use CPAP if they had no OSA, so the utility of this finding is questionable...).