Introduction: Secreted frizzled-related protein 5 (SFRP5), an anti-inflammatory adipokine, is excreted by adipose tissue and may have protective effects on cardiovascular system. In the present study, the relationships of serum level of SFRP5 with the presence and severity of coronary artery disease (CAD) was investigated.  
Materials and methods: In the current study, 40 control subjects, 40 stable and 40 unstable CAD patients were included. Serum level of SFRP5 in all subjects in the study was determined by immunoassay method. The severity of CAD (based on Gensini score) was assigned by angiography examination. The status of conventional risk factors was also determined. Then, the association of SFRP5 with CAD severity and traditional CAD risk factors was explored.
Results: Serum level of SFRP5 was lowest in unstable CAD, followed by stable CAD patients and then control subjects (P < 0.001). The correlation of SFRP5 with Gensini score was significant only in unstable CAD patients (P < 0.01). However, the correlation of SFRP5 with the traditional CAD risk factors was relatively significant and negative in all patients (P<0.05). SFRP5 had a reverse association with the presence of CAD.