Abstract: ObjectiveTo investigate relationship between serum secreted frizzledrelated protein 5 (SFRP5)  and diabetic nephropathy. MethodsA total of 137 patients with type 2 diabetes mellitus were enrolled. According to urinary albumin excretion rate， all patients with type 2 diabetes mellitus  were divided into three groups: normal albuminuria group (group A， n=47)， microalbuminuria group (group B， n=45) and macroalbuminuria group (group C，n=45). The control group included 50 healthy individuals. Serum SFRP5 was determinated with ELISA method. Fasting venous blood samples were collected for glucose and lipid.Twentyfour  hour urine was also collected for UAER. Differences of indexes were compared between groups. ResultsThe level of serum SFRP5 between groups was statistically significant (P<0.05); The level of serum SFRP5 in T2DM group was significantly lower than that of the normal control group (P<0.05); The levels of serum SFRP5 in the microalbuminuria group and macroalbuminruia group were significantly higher than that of normal albuminuria group (P<0.05)， and the level of serum SFRP5 in the macroalbuminuria group was significantly higher than that of the microalbuminuria group (P<0.05). Correlation analysis showed that the levels of SFRP5 were positively correlated with DBP， CHO， TG， FBG， Fins， HOMAIR， BUN， CR and UAER， and negatively correlated with HDL， eGFR and total bilirubin. Multiple linear regression analysis showed that the levels of UAER， HOMAIR， FBG， UA， SBP and TG were independent influencing factors for SFRP5. ConclusionSerum SFRP5 gradually increases as the urinary albumin excretion rate becomes higher in patients with type 2 diabetes mellitus，both may be involved in the occurrence and development of diabetic nephropathy (DN)， and may Serum SFRP5 become a new marker of diabetic nephropathy.

Key words: secreted frizzledrelated protein 5, type 2 diabetes mellitus, diabetic nephropathy