Comparisons with other studies
In a previous study, most parameters of 24-h MII-pH monitoring did not reflect subjective symptoms in the RSI questionnaire in patients with LPR.10 This seems to be due to the non-specificity of LPR-related symptoms, which may be associated with allergy, smoking, environment, toxic inhalant, infection, or voice abuse.18 However, RSI is a validated patient-reported outcome measure and can be used to measure responsiveness to treatment during follow-up in patients with LPR.8,19 Therefore, we investigated RSI continuously during treatment periods to classify patients with LPR into non-responders and responders.
In this study, proximal all reflux time and proximal longest reflux time were significantly higher in responders than in non-responders. Considering that there were no significant differences in the proximal reflux episode according to the reflux type between two groups, the duration of reflux into the pharynx seems to be more important for response to PPI therapy in patients with LPR. Moreover, there were no significant differences in distal MII parameters between two groups. Although the relationship between LPR and GERD is controversial, studies have considered LPR and GERD as different diseases.13,20 Our study indirectly showed that the degree and type of gastroesophageal reflux do not significantly influence the response to PPI therapy in patients with LPR.