GERD Definitions and Epidemiology

Definitions

Gastroesophageal reflux disease (GERD) is characterized by reflux of gastric contents into the esophagus, causing symptoms sufficient to reduce quality of life, and/or esophageal injury. ¹ A more recent global definition states that GERD is a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. ²

The hallmark signs and symptoms of GERD include heartburn and acid regurgitation. Heartburn is a burning sensation in the retrosternal area (e.g., behind the breastbone) that may rise to the back of the throat. ² Acid regurgitation is the perception of flow of refluxed gastric content into the mouth or hypopharynx (e.g., the bottom part of the throat that leads to the esophagus). ² In addition to these dominant symptoms, epigastric pain and/or burning, nausea, chest pain, dysphagia, cough, sore throat, hoarseness, shortness of breath and wheezing can also be present. ¹

Table 1 shows a comprehensive syndrome-based classification system for GERD that reflects the various presentations in different patients. ²

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TABLE 1

Comprehensive classification system for GERD ²

Category	Subcategory	Examples of conditions
Esophageal syndromes	Symptomatic syndromes without esophageal injury Syndromes with or without esophageal symptoms	• Typical reflux syndrome • Reflux chest pain syndrome • Reflux esophagitis • Reflux stricture • Barrett's esophagus • Esophageal adenocarcinoma
Extraesophageal syndromes	Established associations Proposed associations	• Reflux cough syndrome • Reflux laryngitis syndrome • Reflux asthma syndrome • Reflux dental erosion syndrome • Pharyngitis • Sinusitis • Idiopathic pulmonary fibrosis • Recurrent otitis media

Note: While esophageal injury and symptoms are related, they are evaluated on independent axes. Patients may have esophageal injury with or without experiencing symptoms. Conversely, patients who experience symptoms may not necessarily have esophageal injury. Finally, patients who only have extraesophageal symptoms may also experience asymptomatic GERD without esophageal injury.

GERD may also present as uninvestigated dyspepsia. ³ Dyspepsia is characterized as a heterogenous group of symptoms (e.g., pain or discomfort in the upper abdomen) with many underlying causes (e.g., GERD, peptic ulcer disease, gastritis, gastric cancer, drug-induced dyspepsia). ⁴

Endoscopy-negative reflux disease is characterized by the presence of typical troublesome reflux-associated symptoms despite the absence of mucosal breaks at endoscopy (i.e., normal esophagus at endoscopy) while the patient is off treatment.^1,2

Reflux esophagitis, a GERD complication, is characterized by inflammation and ulceration of the esophagus at endoscopy. It is caused by reflux of acidic gastric contents into the esophagus, and affects approximately 30% to 40% of symptomatic patients. Left untreated, reflux esophagitis may progress to esophageal stricture and may also predispose to upper gastrointestinal (GI) bleeding. ⁴

Barrett's esophagus is another potential complication. This condition is characterized by intestinal metaplasia, the replacement of the stratified squamous epithelium (which normally lines the esophagus) with an abnormal columnar epithelium that has intestinal features. While Barrett's esophagus does not usually cause symptoms (and is only diagnosed at endoscopy), it may be a risk factor for esophageal adenocarcinoma. ⁴

Two related GI conditions that are outside the scope of this supplement will only be defined here briefly. Peptic ulcer disease is characterized by erosions and/or ulcerations of the gastric or duodenal walls, due to alterations in the normal defense mechanisms of the mucosa, and acid hypersecretion in select cases. Signs and symptoms include abdominal pain, heartburn, nausea, vomiting, belching and bloating. Some patients are asymptomatic. Two major causes are Helicobacter pylori infection and nonsteroidal anti-inflammatory use. ⁴ Zollinger-Ellison syndrome is characterized by single or multiple GI ulcerations that result from islet cell tumours of the pancreas (gastrinomas) that secrete high levels of gastrin. Symptoms include signs of peptic ulcer disease, but it is a rare syndrome, with an estimated prevalence of 0.1 to 3 per million people in the US. ⁴

Epidemiology

The consensus among Canadian gastroenterology experts is that GERD is the most prevalent acid-related disorder in Canada. ¹

A 1996 population survey of over 1000 Canadian adults estimated that 29% experienced substantial upper GI symptoms in the preceding 3 months (15% had chronic substantial symptoms lasting more than 3 months). Since only 32% of people with chronic symptoms reported being diagnosed by a doctor, it is apparent that pharmacists can play an important role in supporting patients who choose to self-treat their GERD in the community setting. ⁵

GERD appears to affect male and female patients of all ages (pediatric and adult), although extensive epidemiological data on gender and age distributions are lacking. The average age of the adults surveyed in the above study ⁵ was 43.5 years, and the male-to-female ratio was 49.6 to 50.3. Based on comparisons with Canadian census data, this sample was considered representative of the general population. Canadian consensus guidelines indicate that age in itself is not an indication for further investigation, even though the prevalence of esophageal cancer is slightly higher in people over 50 years of age. This increased prevalence is not high enough to justify investigation of all patients over 50 who have GERD symptoms for the first time. However, this does not apply to those patients for whom a diagnosis of Barrett's esophagus is suspected. ¹

Though GERD-related mortality is low, the burden of illness is often quite significant. Previous research shows that patients with GERD have a lower health-related quality of life compared to people with other chronic conditions (including diabetes, hypertension, mild heart failure and arthritis). The reductions in quality of life are common among patients with evidence of erosive esophagitis, as well as those who have endoscopy-negative reflux disease. ¹

A number of conditions have been associated with GERD. For example, a recent meta-analysis demonstrated that obesity is correlated with a statistically significant increase in the risk for GERD symptoms, erosive esophagitis and esophageal adenocarcinoma. Research is ongoing to clarify the relationship between increasing weight, GERD and its complications. ⁶

Dyspepsia accounts for approximately 7% of primary care physician visits, and of this subset, nearly 25% of visits are by patients who are seeking help for the first time. ³ The impact of self-treatment and/or pharmacist consultations on GI symptoms has not been measured.