To investigate the changes and significance of serum cystatin C (CysC) level and urinary microalbumin-creatinine ratio (mAlb/Cr) in patients with type 2 diabetes mellitus (T2DM) complicated by early renal injury.

A total of 103 patients with T2DM admitted to Liaocheng Third People’s Hospital from June 2020 to May 2022 were selected. According to occurrence of early diabetic nephropathy (DN), they were divided into T2DM group (71 cases) and early DN group (32 cases). The level of serum CysC of the two groups were detected, and urinary mAlb/Cr was calculated. The correlation between the level of serum CysC and urinary mAlb/Cr was analyzed. The value of serum CysC level and urinary mAlb/Cr in prediction of early DN was analyzed by receiver operating characteristic curve.

The level of serum CysC and urinary mAlb/Cr in the early DN group were (1.02±0.23) ng/L and 46.59±10.26, respectively, higher than the (0.73±0.18) ng/L and 34.12±8.72 in the T2DM group (P<0.05). The serum CysC level was positively correlated with urinary mAlb/Cr (r=0.34, P<0.001). Results of receiver operating characteristic curve analysis showed that area under the curve (AUC) values of serum CysC level, urinary mAlb/Cr and combination of the two in predicting early DN were 0.827, 0.799 and 0.921, respectively. AUC and evaluation efficiency of combination of the two indicators in predicting early DN were the highest, while its sensitivity and specificity were 93.80% and 78.92%, respectively.

The serum CysC level and urinary mAlb/Cr increase in patients with T2DM complicated by early renal injury. Serum CysC level is positively correlated with urinary mAlb/Cr, and the efficiency of the combination of the two is high in prediction of early DN.

Diabetes mellitus, type 2; Early renal injury; Cystatin C; Microalbumin; Creatinine