Salivary pH testing in Laryngopharyngeal Reflux Disease

Indian J Otolaryngol Head Neck Surg. 2024 Dec;76(6):5812-5817. doi: 10.1007/s12070-024-05109-5. Epub 2024 Oct 5.

Abstract

To determine salivary pH in patients with Laryngopharyngeal Reflux (LPR) and compare it with that of normal individuals. A cross sectional analytical study was done. Adults with LPR as determined by Reflux Symptom Index (RSI) > 13 and Reflux Finding Score (RFS) > 7 were included in LPR group. Normal healthy adult participants with Reflux Symptom Index ≤ 3 and Reflux Finding Score ≤ 2 were included in non LPR group.32 participants were included in each groups. Salivary pH was determined in all participants using a standardized pH meter. Difference in salivary pH between two groups was statistically analyzed. The mean salivary pH in LPR group was 7.43 ± 0.77 and in non LPR group 7.0 ± 0.77. There was a statistically significant difference between the mean salivary pH between the two groups as determined by p value 0.004. The results of our exploratory study showed statistically significant difference in salivary pH between LPR and non LPR group. The salivary pH in 10(31.2%) out of 32 participants in LPR group was beyond the normal range and surprisingly the value was > 7.6, which was in contrast to acidic pH that was expected as per hypothesis. The rest 68.8% in LPR group had pH in the normal range. However salivary pH as a modality for diagnosing LPR cannot be concluded from such preliminary study with a small study population. This study forms a basis for future research for the role of salivary pH in LPR with better study designs and finer modalities of pH testing.

Keywords: Laryngopharyngeal Reflux; Reflux Finding Score; Reflux Symptom Index; Salivary pH.