Saliva secretion is reduced in proton pump inhibitor-responsive non-erosive reflux disease patients

Abstract

There is no consensus on the relationship between saliva secretion and non-erosive reflux disease (NERD). In this study, saliva secretion and salivary epidermal growth factor (EGF) in patients with NERD were examined. Thirty-one PPI-responsive NERD patients and 31 control subjects were recruited for this case–control study. Saliva secretion testing was performed. Saliva secretion was assessed as follows: each patient chewed sugar-free gum for 3 min prior to endoscopy, and the amount and pH of saliva before and after acid loading as an index of the acid-buffering capacity were measured. The salivary EGF concentration was assessed by ELISA. The amount of saliva secreted was significantly lower in the NERD group than in the control group, with medians (25th–75th percentile) of 4.0 mL/3 min (2.0–6.0) and 6.0 (3.9–8.0), respectively (p\u2009=\u20090.0131). Salivary pH was significantly lower in the NERD group (7.0 [6.8–7.2]) than in the control group (7.2 [7.0–7.3], p\u2009=\u20090.0100). Salivary pH after acid loading was significantly lower in the NERD group (5.8 [5.4–6.2]) than in the control group (6.3 [6.1–6.5], p\u2009=\u20090.0002). The difference in pH of stimulated saliva after acid loading (1.2 [0.9–1.5], p\u2009=\u20090.0021) was significantly higher in the NERD group than in the control group (0.8 [0.7–1.1]). The salivary EGF concentration was significantly higher in the NERD group (2513.0 pg/mL [1497.5–5005.0] than in the PPI-responsive group (1641.0 [1139.8–2092.0], p\u2009=\u20090.0032). Stimulated saliva secretion was reduced in PPI-responsive NERD patients.