Diabetic nephropathy (DN) is the common microvascular complication of diabetes mellitus, and also one of the main causes of end-stage renal disease. Renal biopsy is the gold standard for the pathological diagnosis of DN. Previous studies on traditional Chinese medicine (TCM) factors influencing DN lack the basis of renal biopsy, potentially leading to an inaccurate participant recruitment (selection bias) .

To investigate the distribution of TCM syndrome types in DN patients and the relevant TCM syndrome elements in those with massive proteinuria and renal insufficiency, thereby providing TCM research directions in the pathogenesis of DN.

From January 2022 to January 2024, TCM and clinical data of 78 patients diagnosed with type 2 diabetes mellitus (T2DM) with a confirmation of DN through renal biopsy in the Department of Nephrology of First Medical Center of Chinese PLA General Hospital were included. The distribution and clinical characteristics of TCM syndrome types were explored. Binary Logistic regression was employed to explore the TCM syndrome elements associated with massive proteinuria (24-hour urinary protein quantification>3.5 g) and estimated glomerular filtration rate (eGFR) <60 mL·min^-1· (1.73 m²) ^-1 in DN patients.

According to the classification of chronic kidney disease (CKD), there were 11 cases in stageⅠgroup, 19 in stageⅡgroup, 22 in stageⅢgroup, 21 in stageⅣgroup, and 5 in stageⅤgroup. There were significant differences in hemoglobin, eGFR, serum albumin, serum creatinine, serum urea nitrogen, and 24-hour urinary protein in DN patients with different CKD stages groups (P<0.05). Based on the TCM syndrome, there were 11 cases of Yin deficiency and dry heat syndrome, 23 of syndrome of deficiency of both Qi and Yin, 15 of liver-kidney Yin deficiency syndrome, and 29 of spleen-kidney Yang deficiency syndrome. Significant differences were found in hemoglobin, eGFR, serum total protein, serum albumin, serum creatinine, and serum urea nitrogen among DN patients with varying TCM syndrome types (P<0.05). There was a significant difference in the distribution of TCM syndrome types among DN patients in stageⅠ-Ⅴ CKD (P<0.05). In the stageⅠ group, the proportions of Yin deficiency and dry heat syndrome (5/11, 45.5%) and syndrome of deficiency of both Qi and Yin (3/11, 27.3%) were relatively high. In the stage Ⅱ group, the proportions of syndrome of deficiency of both Qi and Yin and liver-kidney Yin deficiency syndrome were 42.1% (8/19) and 31.6% (6/19) respectively. In the stageⅢ group, spleen-kidney Yang deficiency syndrome and syndrome of deficiency of both Qi and Yin accounted for 54.5% (12/22) and 31.8% (7/22), respectively. In the stageⅣ group, spleen-kidney Yang deficiency syndrome and liver-kidney Yin deficiency syndrome accounted for 52.4% (11/21) and 28.6% (6/21), respectively. In the stage Ⅴ group, spleen-kidney Yang deficiency syndrome occupied the highest proportion (3/5, 60.0%). Correspondence analysis indicated that Yin deficiency and dry heat syndrome, syndrome of deficiency of both Qi and Yin, and spleen-kidney Yang deficiency syndrome corresponded to CKD stageⅠ, Ⅱ andⅤ, respectively. Yang deficiency syndrome (OR=3.545, 95%CI=1.270-9.895, P=0.016) and heart location of disease (OR=3.208, 95%CI=1.082-9.511, P=0.035) were the influencing factors of DN combined with massive proteinuria. Yang deficiency syndrome (OR=3.000, 95%CI=1.141-7.890, P=0.026) was the influencing factor of DN combined with eGFR<60 mL·min^-1· (1.73 m^{2) -1}.

The distribution of TCM syndromes of DN transits from Yin deficiency and Qi deficiency to Yang deficiency with the worsening of CKD staging. Yang deficiency syndrome and disease location of heart are factors influencing DN with massive proteinuria, and Yang deficiency syndrome is influencing factor for DN with eGFR<60 mL·min^-1· (1.73 m^{2) -1.} TCM syndrome differentiation combined with modern medicine is conducive to grasping the pathogenesis of DN and advantaging integrated TCM and Western medicine diagnosis and treatment.