AUTHOR=Su Yiliang , Shen Li , Zhang Fen , Jiang Xing , Jin Xiaofeng , Zhang Yuan , Hu Yang , Zhou Ying , Li Qiuhong , Li Huiping 

TITLE=Laryngopharyngeal pH Monitoring in Patients With Idiopathic Pulmonary Fibrosis

JOURNAL=Frontiers in Pharmacology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.724286

DOI=10.3389/fphar.2021.724286

ISSN=1663-9812

ABSTRACT=<p><bold>Background:</bold> Patients with idiopathic pulmonary fibrosis (IPF) often have irritating persistent dry cough. Possible correlations between dry cough and laryngopharyngeal reflux (LPR) remain unclear.</p><p><bold>Methods:</bold> 44 patients with IPF and 30 healthy individuals underwent 24 h laryngopharyngeal pH monitoring. Ryan index score was calculated. Patients’ demographic and clinical data were collected.</p><p><bold>Results:</bold> 44 patients with IPF and 30 healthy individuals were included. The proportions of men and smokers were significantly higher in IPF group than control group (All <italic>p</italic> &lt; 0.01). The average laryngopharyngeal pH value for 24 h was similar in the IPF (7.11 ± 0.08) group and control group (7.09 ± 0.06). According to the percentage duration of pH &lt; 6.5, pH6.5–7.5, and pH &gt; 7.5 in the overall measure duration, the patients were classified into three pH groups. In entire pH monitoring duration, the proportion of pH &gt; 7.5 group in IPF patients was higher than control group; at upright position, the proportion of pH &gt; 7.5 group in IPF patients was higher than control group; at supine position, the proportion of pH &lt; 6.5 group in IPF patients was higher than control group (All <italic>p</italic> &lt; 0.01). Seven patients had Ryan index score&gt;9.41 at upright position. All patients had Ryan index score&lt;6.79 at supine position. Four patients showed significantly higher and one patient had significantly lower average pH at coughing than the overall average pH (All <italic>p</italic> &lt; 0.05).</p><p><bold>Conclusions:</bold> Patients with IPF may have LPR. Basic and acidic LPR may likely occur at upright and supine position, respectively. Ryan index may not accurately reflect LPR in patients with IPF.</p>