Table 2 Eligibility criteria

• DKD diagnostic criteria:

 a) Type 2 diabetes

 b) Diabetic retinopathy

 c) 24-h urinary protein (24 h UP) 0.5–3.5 g

• Serum creatinine <265 μmol/L (3 mg/dl)

• Controlled hypertension (blood pressure ≤ 130/80 mmHg)

• A1C ≤ 8.0

• Chinese syndrome differentiation of qi and yin deficiency with blood stasis

• Taking irbesartan (300 mg daily) continuously in the past 2 weeks

• Between 18 and 70 years of age

• Sign informed consent

• Blood pressure < 90/60 mmHg

• Serum potassium > 5.5 mmol/L or < 3.5 mmol/L

• Doubling of serum creatinine in the past 6 months

• Renal artery stenosis

• Severe diabetes complications or serious macrovascular events within 6 months (e.g., cerebral hemorrhage, massive cerebral infarction, or acute myocardial infarction)

• Recent infection in the past 4 weeks

• Other primary or secondary renal diseases (e.g., IgA nephropathy, membranous nephropathy, or lupus nephritis)

• Any malignancy

• Severe mental disorder

• Pregnant or lactating women or women with the intention of becoming pregnant or women who are not using appropriate contraceptive methods

• Allergic to components of agents used in the study

• Participation in other clinical trials