Factors that Impact Day-to-Day Esophageal Acid Reflux Variability and Its Diagnostic Significance for Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a common disease affecting a significant number of adults both globally and in the USA. GERD is clinically diagnosed based on patient-reported symptoms, and the gold standard for diagnosis is ambulatory reflux monitoring, a tool particularly utilized in the common scenario of non-response to therapy or atypical features. Over the past 20 years, there has been a shift toward extending the duration of reflux monitoring, initially from 24 to 48 h and more recently to 96 h, primarily based on a demonstrated increase in diagnostic yield. Further, multiple studies demonstrate clinically relevant variability in day-to-day acid exposure levels in nearly 30% of ambulatory reflux monitoring studies. For these reasons, an ongoing clinical dilemma relates to the optimal activities patients should engage in during prolonged reflux monitoring. Thus, the aims of this review are to detail what is known about variability in daily acid exposure, discuss factors that are known to influence this day-to-day variability (i.e., sleep patterns, dietary/eating habits, stress, exercise, and medications), and finally provide suggestions for patient education and general GERD management to reduce variation in esophageal acid exposure levels.