Background: To apply non-invasive Autonomic Tongue Diagnosis System in analyzing tongue features in patients with chronic kidney disease.
Material and methods: This was a cross-sectional, case-controlled observational study. Patients with chronic kidney disease who met the inclusion and exclusion criteria were enrolled and divided into the following groups according to renal function and dialysis status: non-dialysis chronic kidney disease group; end-stage renal disease group; and control group. Tongue images were captured and eight tongue features-shape, color, fur thickness, saliva, fissure, ecchymosis, teeth marks, and red dots-were imaged and analyzed by Autonomic Tongue Diagnosis System.
Results: 117 participants (57 men, 60 women) were enrolled in the study, which included 16 in control group, 38 in non-dialysis chronic kidney disease group, and 63 in end-stage renal disease group. We demonstrated significant differences in the fur thickness (P=0.045), color (P=0.005), amounts of ecchymosis (P=0.010), teeth marks (P=0.016), and red dot (P<0.001) among three groups. The areas under receiver operating characteristic curve for the amount of ecchymosis was 0.757±0.055 (95% confidence interval, 0.648-0866; P<0.001).
Additionally, with increase in ecchymosis by one point, the risk of chronic kidney disease dialysis rose by 1.523 times (95% confidence interval, 1.198-1.936; P=0.001). After hemodialysis, the amount of saliva(P=0.038), the area of saliva(P=0.048) and the number of red dots(P=0.040) were decreased significantly among patients with end-stage renal disease. On the contrary, the percentage of coating(P=0.002) and area of coating(P=0.026) were increased significantly after hemodialysis.
Conclusions: Blood deficiency and stasis with qi deficiency or blood heat syndrome (Zheng pattern) is common in patients with chronic kidney disease. The risk of chronic kidney disease dialysis increases with increasing ecchymosis. Hemodialysis can affect saliva, tongue coating, and relieve heat syndrome among end-stage renal disease patients.