Objective tongue color and gastroesophageal reflux disease: Cross-sectional study

Aim: Gastroesophageal reflux disease (GERD) is a heterogeneous, multi-symptom disease. The Frequency Scale for the Symptoms of GERD (FSSG) is used to evaluate the disease severity and therapeutic response. We reported that objective tongue diagnosis would be a useful, non-invasive screening tool for erosive gastritis, which makes it a useful complement to Kampo diagnosis. This study was done to investigate the utility of tongue color (TC) and FSSG in the diagnosis of GERD. Methods: A total of 886 healthy Japanese residents aged 28–86 years had a photograph of the tongue taken, completed the FSSG, and underwent esophagogastroduodenoscopy. FSSG ≥8 was defined as GERD, mucosal break on endoscopy as reflux esophagitis (RE), and no erosive esophagitis as non-erosive reflux disease (NERD). TC was measured using the device-independent International Commission on Illumination (CIE) 1976 L*a*b* color space standards at four points. Results: A total of 152 (17.2%) of the subjects had FSSG ≥8. On endoscopy 36 (4.1%) had RE and 116 (13.1%) had NERD. Age, sex, and smoking were significant in the multivariate analysis of GERD (OR, 0.64, P = 0.043; OR, 0.65, P = 0.036; and OR, 2.06, P = 0.014, respectively). Sex and TC (3b*/1b*) were significant in the multivariate analysis of RE (OR, 4.82, P < 0.001; OR, 3.59, P = 0.018, respectively). On receiver operating characteristics analysis, a combination of sex (male) and TC (3b*/1b*) ≥1.24 was more predictive of RE than sex (male) alone (area under the curve, 0.75 vs 0.70). Conclusion: Combining FSSG ≥8, sex, and a positive tongue color coating would be a useful, accurate, non-invasive screening method for GERD, especially RE.