Gastroparesis is Not Associated with Acid or Non-Acid Reflux

Abstract

Purpose: Gastroparesis (GP) may often be misdiagnosed as gastroesophageal reflux disease (GERD) given the similarity in symptoms of regurgitation related to high volume reflux. Prior studies have suggested an association between delayed stomach emptying and refractory GERD. Unfortunately, unlike GERD, the symptoms of GP do not respond to acid suppression therapy. Whether non-acid reflux contributes to this lack of symptom improvement in patients with GP is unknown. Our study aims to determine whether an increased number and duration of acid and non-acid reflux episodes as measured using the Multichannel Intraluminal Impedance pH (MII-pH) is seen in patients with GP as compared to controls. Methods: The baseline characteristics, MII-pH data and gastric emptying scintigraphy (GES) results were reviewed on 40 consecutive patients undergoing clinical evaluation for continued heartburn and regurgitation despite acid suppression therapy. All enrolled subjects were continued on their PPI for the duration of the study. The 8 channel MII-pH probe recorded impedance data at 3, 5, 7, 9, 15 and 17 cm above the LES and pH data 5 cm above and 10 cm below the LES. The MII-pH parameters evaluated were as follows: total, supine and upright number of acid reflux episodes (pH <4); total, supine and upright number of non-acid reflux episodes as defined by pH >4; duration of acid and non-acid reflux in 24 hour period and the number of reflux episodes lasting over 5 minutes. GES results were reviewed with a normal study defined by gastric emptying half-time of 45-90 minutes. The control group (n=25, 6M, 19F, mean age 51) consisted of subjects with symptoms of regurgitation on PPI therapy and a normal GES, and the GP group (n=15, 4M, 11F, mean age 54) consisted of those subjects with an abnormal GES and/or history of GP. Results: Using SAS software, the impedance parameters listed above were compared between patients with GP and controls. The t-test for equality of the mean showed no statistical difference between the two groups with respect to the total number or duration of acid reflux events (p value=0.9), total number and duration of non-acid reflux events (p value=.6) or the duration of longest reflux episodes (p value=.5). The number of non-acid reflux events with pH >7 was slightly higher in the GP group than the controls (mean=5.47 ± 5.2 versus mean=4.84 ± .6.0, p value=0.7). Conclusion: Despite previous studies suggesting an association between refractory GERD and GP, we did not find increased reflux duration or increased number of reflux episodes in patients with GP. We conclude that delayed gastric emptying is not associated with either acid or nonacid reflux.