Sleep Apnea Caused by Reflux, or Reflux Caused by Sleep Apnea? An Expert Interview with Prof. Dr. Zehetner

Prof. (USC) Dr. med. Jörg Zehetner is a renowned specialist in visceral surgery with a particular focus on upper abdominal surgery. He has outstanding expertise in the treatment of diseases of the esophagus and stomach, including cancer, gastroesophageal reflux disease (GERD), and obesity. He is also one of the leading experts in bariatric surgery and the surgical management of complex hiatal and abdominal wall hernias. As a board-certified surgeon specializing in visceral surgery and a longtime professor at the University of Southern California (USC), he combines excellent medical expertise with international experience.

Dr. Zehetner completed his medical training in Switzerland, Austria, and Spain before finishing his surgical residency at renowned hospitals in Switzerland and Austria. After several years as a senior resident in Linz, he continued his career in the United States, where he spent seven years conducting research and teaching at the University of Southern California (USC) in Los Angeles. He has received multiple awards for his outstanding achievements in teaching and is an honorary member of the Society of Graduate Surgeons at USC.

Since 2015, Dr. Zehetner has been practicing as an affiliated physician at the Hirslanden Klinik Beau-Site as well as in his own practice in Bern. In 2017, he took full ownership of the practice and founded Swiss1Chirurgie AG, which now operates at several locations throughout Switzerland. Swiss1Chirurgie is now the largest private practice for bariatric and reflux surgery in Switzerland. Together with the Center for Bariatric Surgery (ZfbC), he treats approximately 3,500 patients annually. This comprehensive care is complemented by the network of specialists at Helvetius Holding AG, which includes not only Swiss1Chirurgie but also gastroenterology and general practice clinics. As a result, patients benefit from interdisciplinary care of the highest standard.

Dr. Zehetner is regarded as one of Europe’s leading experts in reflux and bariatric surgery and is particularly sought after for complex revision surgeries. He has extensive experience in minimally invasive surgery, including high-precision robotic surgery. His particular focus is on the treatment of gastroesophageal reflux disease (GERD), a condition that, if left untreated, can lead to serious consequences such as chronic bronchitis or esophageal cancer. Dr. Zehetner is the only surgeon in Switzerland who has mastered all established and new surgical methods in reflux surgery. This enables him to select the optimal treatment strategy for each patient individually and offer highly precise, personalized therapy.

The editorial team of the Leading Medicine Guide learned more about the connection between sleep apnea and reflux in a conversation with Dr. Zehetner.

Reflux and sleep apnea are two widespread conditions that, at first glance, appear unrelated. However, a growing body of scientific evidence suggests that they are closely linked. While nocturnal reflux can irritate the airways and significantly impair sleep quality, sleep apnea, conversely, also appears to promote the reflux of stomach acid. This complex feedback mechanism can not only significantly impair the quality of life for those affected but also have long-term health consequences. A closer look at this connection reveals why early diagnosis and targeted treatment are crucial in both areas. 

Gastroesophageal reflux (GERD) and sleep apnea are two common conditions that are often linked. Various underlying causes and risk factors can contribute to both GERD and sleep apnea while simultaneously exacerbating their symptoms.

A key risk factor is being overweight or obese. People who are overweight have an increased risk of developing both GERD and sleep apnea. “Personally, as a reflux specialist and an expert on obesity, I often see patients who are overweight, have sleep apnea, and suffer from reflux. There is occasionally an overlap here. Reflux and sleep apnea are two distinct medical conditions that can be considered independently of one another, but there are some connections regarding causes and risk factors. One risk factor is being overweight (often starting at a BMI of 27), as this puts increased pressure on both the stomach and the throat area. It has been found that in 70% of overweight patients, sleep apnea resolves when they lose weight appropriately. Patients with sleep apnea also experience greater negative pressure in the chest cavity. This is because when a patient with sleep apnea suddenly takes a deep breath, it creates negative pressure in the thorax, which draws stomach acid upward. This then has various effects. However, it is not known whether sleep apnea is the cause—because it draws stomach acid upward—or whether the patient takes a reflexive pause in breathing because stomach acid has risen. There are also theories that there are sensors in the esophagus that close the epiglottis when irritation occurs to protect the lungs,” explains Prof. Dr. Zehetner, adding:

“Another risk factor is alcohol consumption, since alcohol causes the entire throat and pharynx to relax. Of course, smoking and an unhealthy diet are also risk factors. When it comes to diet, this specifically refers to eating too many processed foods or fast food—and simply eating too much. Coffee plays a minor role, because although coffee is actually good for digestion, caffeine can cause the lower esophageal sphincter to relax, allowing stomach acid to shoot upward. “And once the acid is there and triggers a reflexive 30- to 40-second pause in the patient’s breathing, the patient suddenly takes a deep breath, which draws even more acid upward.”

Nocturnal reflux can exacerbate the symptoms of sleep apnea in various ways and has a significant impact on the sleep quality of those affected.

During sleep, especially when lying on one’s back, relaxed muscles and a reduced swallowing reflex increase the likelihood that stomach acid will rise into the esophagus. The repeated nighttime awakenings caused by reflux symptoms or breathing pauses lead to fragmented sleep and a significant reduction in sleep quality. Constant waking and repeated disruptions prevent a restful night’s sleep and can lead to chronic sleep deprivation. These sleep disturbances, in turn, contribute to a worsening of sleep apnea and reflux and lead to a further reduction in quality of life, as those affected suffer from fatigue and reduced performance during the day as well as from distressing symptoms at night.

“It is often family members who notice regular and continuous snoring accompanied by pauses in the affected person’s breathing—so-called breathing pauses that can last from a few seconds to a minute, followed by a loud gasping sound. The patient themselves experiences headaches during the day and suffers from difficulty concentrating and daytime sleepiness because the pauses in breathing at night cause CO2 levels in the brain to rise, resulting in a reduced supply of oxygen. Patients with these symptoms often visit their primary care physician, who frequently prescribes a mask for nighttime use that delivers positive airway pressure. While this treats the sleep apnea, it does not address the underlying cause. However, the possible causes—obesity or reflux—must be treated! Therefore, patients and treating physicians who suspect sleep apnea should perform or recommend a gastroscopy with acid measurement. “This is performed over a period of 48 hours or more using a small capsule (Bravo or Alpha capsule), which allows for wireless measurement in the nose of how much acid refluxes upward while the patient is lying down,” recommends Prof. Dr. Zehetner.

Various diagnostic procedures are used to determine whether a patient with sleep apnea also has reflux that requires treatment. The choice of the appropriate method depends on the clinical symptoms, the severity of the complaints, and the available resources.

“A key component of the diagnostic process is a detailed medical history, as many patients with sleep apnea also suffer from frequent heartburn or other reflux symptoms. During the consultation, we try to determine the exact nature of the patient’s reflux and sleep apnea and whether there are any connections to their lifestyle.” We perform functional tests at our gastroenterology group practice. In addition to an upper endoscopy, these include esophageal manometry and the aforementioned acid measurement at the lower end of the esophagus. During the gastroscopy, we can also assess whether a hiatal hernia is present, and the lower end of the esophagus can be visually examined. Inflammation and changes in the mucosa can also be detected this way. All of this can be done in a single day. The patient simply takes the capsule for acid measurement home and returns to us after approximately 48 hours for evaluation of the results,” says Prof. Dr. Zehetner, describing the diagnostic procedure.

Treatment for patients suffering from both gastroesophageal reflux disease (GERD) and obstructive sleep apnea (OSA) should be comprehensive and include both pharmacological and non-pharmacological approaches, as well as surgical options if necessary. 

Since both conditions can influence each other, targeted treatment is crucial for alleviating symptoms and improving the quality of life for those affected. One of the most important measures is lifestyle modification. 

“If a patient is slightly overweight (BMI 25–27), we offer nutritional counseling. For patients with a BMI over 28, we offer a consultation at our Center for Bariatric Surgery to discuss conservative therapy with GLP-1 (weight-loss injections) and close monitoring. For patients with a BMI of 35 or higher, we recommend laparoscopic gastric bypass surgery as the gold standard. Sleeve gastrectomy is not ideal for patients with reflux. For patients who are not overweight, the symptoms must be more thoroughly evaluated—for example, to determine whether they have a chronic cough or voice changes, or whether they have previously had lung problems such as bronchitis or pneumonia. In such cases, I would definitely recommend reflux surgery. “Of course, there is a small percentage of patients who, despite reflux evaluation and/or surgery, still need a CPAP machine at night to generate positive airway pressure,” says Prof. Dr. Zehetner, adding:

“There are other treatment options for sleep apnea that are of interest to patients who do not have reflux: sleep apnea mouthguards. These mouthguards fit in the mouth like braces and push the lower jaw forward. This creates more space in the throat, which reduces snoring and the number of sleep apnea episodes. Such a splint would then need to be worn every night. For patients with a malocclusion, a visit to an oral surgeon is sometimes recommended to have the problem corrected—though this scenario is very rare in the context of sleep apnea.”

---

Initial results vary depending on the method used:

For reflux surgery: after about 2–3 weeks

For bariatric surgery: after about 3 months

It can take up to six months in total for sleep apnea to resolve, as the stomach lining and the reflux sensors in the lungs need that much time to normalize and regress.

---

Lifestyle plays a crucial role in the interaction between gastroesophageal reflux disease (GERD) and obstructive sleep apnea (OSA), as both conditions are influenced by various factors in daily life.

An unhealthy diet, being overweight, alcohol and nicotine use, and certain sleep habits can exacerbate both reflux and sleep apnea. However, targeted lifestyle adjustments can often significantly alleviate the symptoms of both conditions. Certain foods, such as high-fat meals, carbonated beverages, chocolate, coffee, citrus fruits, and heavily spiced dishes, can increase stomach acid production and worsen reflux. Late-night meals should also be avoided, as lying down on a full stomach promotes reflux. An easily digestible, low-acid diet rich in fiber can relieve strain on the gastrointestinal tract and reduce reflux symptoms.

“Good sleep hygiene is important. You shouldn’t eat too much in the evening—smaller portions are better. It’s best to have your last meal two hours before bedtime. You should also avoid nicotine, caffeine, and alcohol. It’s also unhealthy to spend too much time in front of a screen, whether watching TV or using a cell phone. The ideal bedroom temperature is 16–20 °C. And then, of course, it’s important to take the time to actually sleep well. “However, patients who suffer from sleep apnea can lie in bed for as long as they want—they simply lack regular and uninterrupted sleep,” says Prof. Dr. Zehetner, adding at the end of our conversation:

“I personally perform about 150 reflux surgeries, and approximately 350 bariatric surgeries are performed at the Beau-Site Clinic in Bern, making us number one in Switzerland. Here’s a tip I’d like to share: If someone notices they’re not sleeping well, they should always consider the possibility of reflux. There’s also silent reflux—without acid regurgitation or heartburn—but it can still lead to esophagitis. In such cases, patients often endure a long ordeal before receiving the correct diagnosis.”

Thank you very much, Professor Dr. Zehetner, for this important information on reflux and sleep apnea!