Background: Tongue diagnosis plays an important role in clinical prognosis and treatment of chronic kidney disease (CKD) in the traditional Chinese medicine (TCM). By observing tongue features, TCM practitioners can probe qi-blood, yin-yang disorders which are important in treatment selection and prognosis. This study investigated discriminating tongue features to distinguish the relationship between patients with CKD stage 3-5 through non-invasive TCM tongue diagnosis.
Method: We conducted a cross-sectional study of 577 patients with CKD (stage3=383, stage4=93, stage5=23, dialysis=78) and compared demography, laboratory and tongue manifestation data. There are 9 primary features for TCM clinical tongue diagnosis including tongue shape (small, moderate and fat ), tongue color (slightly white, slightly red, red, dark red, dark purple), fur color (white, yellow, dye), fur thickness (none, thin, thick), saliva (none, little, normal, excessive), tongue fissure, red dot, ecchymosis, tooth marks, and engorged sublingual collateral vessels. Analysis of tongue images was conducted by 3 Chinese medical physicians who had 5 years of clinical experience in the Chinese medicine department of Changhua Christian Hospital (CCH), Taiwan.
Results: Patients with CKD stage 5 possessed significantly fat tongue shape (P<.001), slightly white color (P<.001), ecchymosis (P= 0.002), tooth marks (P=0.004), engorged sublingual collateral vessels (P<.001). The proportion of engorged sublingual collateral vessels in dialysis patients was lower than CKD stage 5 patients (95.7% vs 10.3%).
Conclusion: The high prevalence of fat tongue shape, slightly white color, ecchymosis, tooth marks and engorged sublingual collateral vessels in patient with CKD stage 5. TCM tongue diagnosis can serve as a preliminary screening procedure in the detection of the severity level of kidney disease in light of its simple and non-invasive nature, followed by other more accurate testing process.