Proprotein Convertase Subtilisin/Kexin Type 9

I read the letter by Sahebkar proposing ‘‘a link between serum resistin levels and cardiovascular events.’’ Sahebkar suggests that a positive correlation between serum levels of resistin and the severity of coronary artery disease (CAD) could be an attenuated response to statin therapy in patients with higher serum resistin levels, thereby causing an increased susceptibility to atherosclerosis. The author discussed some studies that support this concept. In our study, 96 (58.5%) of the 164 patients in the CAD(þ) group and 18 (36%) of the 50 patients in the control group had hyperlipidemia (P 1⁄4 .006). The use of statins was higher in the CAD(þ) group than that in the control group. However, the mean low-density lipoprotein cholesterol (LDL-C) levels were similar in 2 groups (122 + 34 mg/dL in the CAD(þ) group and 124 + 34 mg/dL in the control group). Although we do not have information regarding the statin doses used in each group, we would have expected lower mean LDL-C levels in the CAD group because of higher statin use. In conclusion, we do not have enough information to substantiate whether elevated resistin levels are associated with a poorer response to statin therapy. As Sahebkar suggests, large-scale clinical end point statin trials should consider post hoc analyses in order to elucidate whether the efficacy of statin therapy in reducing cardiovascular outcomes varies between different subgroups stratified by serum resistin levels.