CST3 and diabetic kidney disease: Univariate logistic regression analysis exhibited that age (OR = 0.938; P=0.043), postprandial glucose/C-peptide (OR = 0.851; p ≤ 0.001), insulin resistance index (OR = 0.219; p ≤ 0.001), serum cystatin C (OR = 0.113; p ≤ 0.001), and uric acid (OR = 0.989; P=0.001) were risk factors for the risk of disease progression in diabetic nephropathy patients.