The association between salivary pepsin and gastroesophageal reflux disease: A meta-analysis.

Background and purpose: The definitive diagnosis of gastroesophageal reflux disease (GERD) often requires invasive investigations like upper gastrointestinal endoscopy or reflux monitoring. We aimed to explore the relationship between salivary pepsin and GERD and its value as a non-invasive diagnostic tool.

Methods: Databases (PubMed, Web of Science, Cochran Library, and EMBASE) were searched from their inception to January 22, 2024 to explore the correlation of salivary pepsin with GERD. The meta-analysis data retrieved were summarized, including the salivary pepsin concentration, sensitivity of diagnosis (SEN), specificity of diagnosis (SPE), negative likelihood ratio, positive likelihood ratio, diagnostic odds ratio, and receiver operating characteristic (ROC) curve.

Results: The meta-analysis comparing salivary pepsin concentration in two groups (proven GERD and non-GERD) with 18 studies revealed that the proven GERD group had higher salivary pepsin concentration than the non-GERD group (SMD = 1.74 [95% CI 1.14-2.34]). The meta-analysis of salivary pepsin diagnostic value for proven GERD incorporated 23 studies. The results showed pooled SEN (0.73 [95% CI 0.66-0.80]), SPE (0.72 [95% CI 0.65-0.78]), positive likelihood ratio (2.61 [95% CI 2.02-3.39]), negative likelihood ratio (0.37 [95% CI 0.28-0.50]), diagnostic odds ratio (7.03 [95% CI 4.24-11.66]) and area under the SROC curve (0.79 [95% CI 0.75-0.82]).

Conclusion: GERD patients presented a higher salivary pepsin concentration. Salivary pepsin is both sensitive and specific in identifying GERD, making it a promising non-invasive marker for diagnosis.