Gastroesophageal reflux disease in runners.

Abstract

As recreational and competitive running increase in popularity, information concerning running- related gastroesophageal reflux is accumulating. Many studies have documented that runners experience increased gastroesophageal reflux and subsequent symptoms. Upper gastrointestinal symptoms that can accompany running include heartburn, belching, nausea, bloating, and chest pain. It remains unclear to what extent running-related gastroesophageal reflux provokes these symptoms. Some acid inhibiting medications may moderate these symptoms. This paper is intended to provide an overview of running-related gastroesophageal reflux, and make recommendations for treating affected athletes.

Keywords: athlete, runner, acid reflux, gastroesophageal 

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Although running has steadily increased in popularity throughout the second half of the 20th Century, descriptions of running-related gastroesophageal reflux (GER) did not begin to appear in the medical literature until the 1990's(1). As this phenomenon has been studied, it appears that it is quite common and it may affect both recreational and competitive runners. Recent studies have shown that upper gastrointestinal symptoms are endemic among endurance athletes with 20 to 50 percent complaining of nausea, vomiting, belching, bloating, heartburn, chest pain, and cramps(2). Gastroesophageal reflux likely plays an important role in many of these cases. The definition of GER is simply the passage of gastric contents (predominantly acid) retrograde into the esophagus. GER occurs periodically in normal individuals. However, if it becomes a regular occurrence, it will sometimes result in damage to the esophageal mucosa. The amount of tissue damage appears to be proportional to the degree of acid exposure. Addition ally, exposure of the esophagus to gastric acid is largely responsible for symptoms. These symptoms may limit performance in both recreational and competitive runners. Interventions are available to minimize GER symptoms during running.

Potential Etiologies for Running-Related Gastroesophageal Reflux Lower Esophageal Sphincter Relaxation

The lower esophageal sphincter (LES) is a relatively high pressure zone which separates the stomach from the esophagus. A gradient of 12 mm Hg exists between the stomach and esophagus, favoring the movement of gastric contents proximally. The LES serves as the primary barrier to GER When the pressure across the LES is lowered it can result in GER and possibly symptoms.

Recent studies have shown that the decrease in LES pressure in athletes and others is not a persistent phenomenon, but occurs as an abrupt transient relaxation (3). Transient LES relaxation is probably a physiologic response to gastric distention, which stimulates mechanical receptors in the fundus. This signal in turn results in LES relaxation, causing belching and venting of trapped air. The duration of transient LES relaxation also seems to be an important factor in GER(3). The exact mechanism by which running predisposes to GER and possible symptoms is not clearly understood.

Transient LES relaxation may be provoked by increased respiratory rate, deep inspirations, and decreased intra-thoracic pressure which can occur during running.

Gastrointestinal Motility 

Peristalsis and normal gastrointestinal motility is a critical factor in the prevention of GER and upper gastrointestinal symptoms. Organized contractions of the esophagus push refluxed gastric contents back into the stomach after it is neutralized from bicarbonate in saliva. Similarly, normal gastric emptying largely prevents the retrograde movement of stomach contents. Soffer et al. found that increased intensity of exercise decreased the duration, frequency, and amplitude of esophageal contractions. This resulted in increased GER(4). Another study, by Peters et al., found that strenuous exercise resulted in uncoordinated esophageal contractions and GER(5). Thus, it appears that exercise effects gastrointestinal motility in a manor that may result in GER.

Gastrointestinal Hormones

There has been one study concerning the effect of exercise on gastrointestinal hormones and GER(6). This study measured gastrin, glucagon, motilin, pancreatic polypeptide, and vasointestinal peptide during exercise. Neither hormone levels nor GER episodes increased with exercise. Thus, the role of gastrointestinal hormones in exercise-induced GER does not appear to be major, although confirmatory studies may be required.

Food and Medications

Ingestion of large amounts of food prior to running may predispose to GER and upper gastrointestinal symptoms, in several different ways. First, a sizeable meal will stimulate gastric acid production. Secondly, decreased gastric emptying will occur, especially after a solid and/or fatty meal. Also, various types of food will promote GER, usually by causing the LES to relax. Greasy foods, chocolate, mints, and caffeine are notorious culprits. Several classes of prescription medications may exacerbate running-induced GER. Nitrates, calcium channel blockers, and estrogens all act as smooth muscle relaxants. Relaxation of the LES and GER may ensue. Certainly, consultation with a physician should occur prior to stopping or changing medications as a result of exercise-induced GER. The effects of a recent meal or medication in causing GER are additive to the effects of exercise itself as a source of gastrointestinal reflux.

Clothing

Clothing that fits tightly around the waist will often increase intra-abdominal pressure. GER and upper gastrointestinal symptoms may result. This may be especially true in overweight runners, as increased weight tends to also increase intra-abdominal pressure and exacerbate GER.

Evaluation and Treatment

Runners who experience frequent symptoms of GER should see their healthcare provider. This is especially important in runners who have chest discomfort. Upper gastrointestinal symptoms, such as chest pain need to be differentiated from life threatening cardiac disorders.

Once heart disease has been excluded, diagnosis and treatment of GER related symptoms should be pursued. Persistent heartburn, difficulty swallowing, or pain on swallowing should certainly be evaluated. Several tests can be done in the assessment of GER symptoms. A common practical approach is to institute a trial of acid suppressive medication. There is some data which suggests that this approach has similar sensitivity and specificity to 24 hour esophageal pH monitoring in diagnosing GER(7). Esophageal pH probe monitoring can document episodes of acid reflux and correlate these episodes with symptoms. The patient has the probe placed through the nose into the esophagus, and wears it for 24 hours. The patient also keeps a diary of symptoms. This test can help the physician diagnose or exclude GER related symptoms. Kraus et al. evaluated fourteen runners with probe studies (1). This group studied athletes at baseline and during running. They concluded that compared to baseline, GER occurs more frequently in h ealthy volunteers during running, and is usually associated with belching.

For possible upper gastrointestinal symptoms possibly related to GER, endoscopy may be usefully employed. Upper endoscopy is especially important when the runner has experienced heartburn refractory to medication, difficulty swallowing, or pain on swallowing. Endoscopy will allow the physician to directly examine the esophageal mucosa and biopsy for any abnormalities. This test can exclude several dangerous conditions such as cancer, stricture, infection, or a pre-malignant form of esophagitis termed Barrett's esophagus. Endoscopy may also reveal classical GER related esophagitis which can be readily treated.

In cases of chest pain that is not cardiac in origin, esophageal motility studies may be of assistance. During this examination the pressure waves in the esophagus are measured by a sophisticated catheter that is emplaced either nasally or orally. This modality can make the diagnosis of an esophageal motility disorder, which in turn can be treated with acid inhibition or smooth muscle relaxants.

The treatment of running-related GER symptoms begins with lifestyle modification. Although most runners are trim, those who tend to be heavy may notice a positive effect on GER symptoms with weight reduction. Again, most runners do not take excessive amounts of alcohol or tobacco. However, those that do may stop GER symptoms by curtailing use. Large, fatty meals should be avoided just prior to running in an effort to reduce frequency and severity of GER. Finally, clothing which fits tightly across the mid-section should be avoided during exercise if GER symptoms are suspected. Caffeine, chocolate, mint, citrus (fruit or juice), and onions may exacerbate running-related GER. Omission of these items from the diet may provide a simple therapeutic intervention. As mentioned previously, certain medications may provoke GER Consultation with a physician may result in alteration in medication regimens, and diminished GER symptoms.

There are various medications for the treatment of GER symptoms, and some of them have been studied in runners. Antacids are the most basic GER medication and are found over the counter in tablet and liquid form. These medications can be helpful for infrequent and/or fleeting GER symptoms. Antacids tend to work for about two hours per dose. For more significant symptoms, H2 blockers such as cimetidine and ranitidine can be used. A study of runners taking ranitidine and wearing pH probes showed decreased intra-esophageal acid exposure during running(1). This class of drug tends to work for six to twelve hours per dose. The strongest acid inhibiting class of drugs is the proton pump inhibitors. These can only be provided by prescription and are used to treat severe cases of GER or complications of GER. They are long acting medications, usually providing symptom relief for 24 hours per dose. One study has documented that running induced acid reflux was decreased on proton pump inhibition (omeprazole)(2). However , this study failed to show a reduction in symptoms with the use of the drug. They concluded that most symptoms were likely unrelated to GER. In cases of recalcitrant GER symptoms, the use of motility drugs and even surgery can be considered. Consultation with a specialist is advisable in these instances.

In conclusion, runners probably experience increased episodes of GER during exercise. Many of these episodes are asymptomatic. However, persistant symptoms such as heartburn, belching, nausea, vomiting, bloating, chest pain, or swallowing problems should be evaluated. Treatment for GER related symptoms most commonly involve lifestyle modification and medication.

References

(1.) Kraus BB, Sinclair JW, castelldo. Gastroesophageal reflux in runners. characteristics and treatment. Ann Intern Med 1990; 112: 429-33.

(2.) Peters IIPF Bos M, et al., Gastrointestinal Symptoms in Long -Distance runners, cyclists and Triathletes: Prevelance, Medication, Etiology American Journal of Gastroenterlogy 1999. Vol 94. No 6. 1577-1581.

(3.) Behar J, The role of the lower esophageal spincter in reflux prevention. J Clin Gastroenterlogy 1986,8 (suppl); 2-4.

(4.) E E Soffer R,W Summers, C Gisolfi. Effect of exercise on intestinal motility and transit in trained athletes. Am J physiol 1991; G698-702.

(5.) Peters L, Mass L, Petty D. Spontaneous non cardiac chest pain: Evaluation 24-hour ambulatory esophageal motility and Pit monitoring. Gastroenterology 1988; 94; 878.86.

(6.) Sullivan SN, Champion MC et al. Gastrointestinal regulatory peptide responses in long distance runners. Physician sports Med 1984; 12;77-82.

(7.) Schenk BE, Kuipers EJ, et al. Omeprazole as a diagnostic tool in gastroesopltageal reflux disease. Am J Gastoenterol 1997; 92(11).

(8.) Riddoch c, Trinick T. Gastrointestinal disturbances in marathon runners. Br J Sports Med 1988; Jun 22(2)71-4.

Address correspondence and reprint requests to:

John M. Levey, M.D.

University of MA Medical School, Div. of Gastrointestinal and Hepatobiliary Medicine, St. Vincent Hospital/Worcester Medical Center, The Fallon Clinic, 20 Worcester Center Blvd, Worcester, MA 01608