Reflux, Sleep Apnea and Increased Survival in Lung Disease
Posted May 29 2013 9:44pm
This blog post’s topic may sound completely unrelated to obstructive sleep apnea, but here’s a study showing that in people with idiopathic pulmonary fibrosis, being placed on an acid reflux medication (proton pump blocker) boosted survival significantly by about 2 years (3.4 vs. 1.4 years). The author’s explanation is somewhat complicated:
“DDAH and inducible nitric oxide synthetase are increased in lung epithelium and fibroblastic foci in IPF, and we found that proton pump inhibitors inhibit DDAH.”
In other words, Proton pump inhibitors, such as Prilosec, Nexium, or Aciphex have properties that prevent a complex pathway that leads to inflammation in the lungs. This phenomenon was also seen in subjects that had no reflux symptoms, leading the authors to postulate that a non-reflux mechanism could explain the survival benefit.
Here’s a simpler possible explanation: Many people with obstructive sleep apnea have silent reflux, due to vacuum forces that are created in the chest and throat during an apnea. Stomach juices (which include acid, bile, digestive enzymes, and bacteria) travel up into the throat, and then down into the lungs, causing chronic long-term inflammation. Treating with acid reducers may lower the acidity of the juices going into the lungs, thus possibly increasing survival.
The problem with using reflux medications is that they don’t really do anything for reflux. They only lower acid levels in the stomach, but what comes up into the throat is just less acidic. However, you still have bile, enzymes and bacteria, which can be very caustic to the lungs (or ears or sinuses).
It would be interesting to do a similar study, but instead, screen for and treat obstructive sleep apnea in patients with IPF, and see what the results show.