Persistent symptoms on acid suppressive therapy are due to either acid or nonacid gastroesophageal reflux (GER) episodes or are not related to reflux.
To compare physical and chemical characteristics of GER episodes associated with symptoms in patients on acid suppressive therapy.
Patients with persistent symptoms on acid suppressive therapy underwent combined impedance-pH monitoring. Reflux episodes were classified as acid if nadir pH was <4.0, and nonacid if it remained at ≥4.0, separated into liquid-only or mixed (liquid-gas), and considered to reach the proximal esophagus if liquid was present 15 cm above the lower esophageal sphincter (LES). Reflux episodes were considered symptomatic if patients recorded a symptom within 5 min after the reflux episode. Risk factors of symptomatic reflux episodes were identified using multivariable generalized estimating equations (GEEs).
One hundred twenty patients (85 women, median age 54 yr, range 18–85 yr) recorded 3,547 reflux episodes (84.3% nonacid, 50.6% mixed), of which 468 (13.2%) were symptomatic. Based on multivariable GEE analysis with episode-level symptom status (symptomatic vs nonsymptomatic) as the outcome variable, reflux episode acidity was not significantly associated with symptoms (P= 0.40). Mixed reflux episodes were significantly associated with symptoms relative to liquid-only episodes (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.19–1.87, P= 0.0005), as were reflux episodes reaching the proximal esophagus compared with those reaching the distal esophagus only (OR 1.28, 95% CI 1.06–1.55, P= 0.012).
The majority of reflux episodes on acid suppressive therapy are asymptomatic. Reflux episodes extending proximally and having a mixed (liquid-gas) composition are significantly associated with symptoms, irrespective of whether pH is acid (<4) or nonacid (≥4).
1Division of Gastroenterology and Hepatology, Medical University of South Carolina, Charleston, South Carolina; and 2Department of Biostatistics, Bioinformatics and Epidemiology, Medical University of South Carolina, Charleston, South Carolina
Reprint requests and correspondence: Radu Tutuian, M.D., Division of Gastroenterology and Hepatology, University Hospital of Zurich, Ramistrasse 100, A HOF 109, CH-8091 Zurich, Switzerland.
CONFLICT OF INTEREST Guarantors of the article: Radu Tutuian, M.D., and Donald O. Castell, M.D.
Specific author contributions: data collection: Radu Tutuian, Marcelo F. Vela, Inder Mainie, Amit Agrawal, and Donald O. Castell; data analysis: Elizabeth G. Hill, Radu Tutuian, and Marcelo F. Vela; and writing and approving the final version of the manuscript: Radu Tutuian, Marcelo F. Vela, Elizabeth G. Hill, Inder Mainie, Amit Agrawal, and Donald O. Castell.
Financial support: None.
Potential competing interests: None.
Received July 27, 2007; accepted December 11, 2007.