The role of proprotein convertase subtilisin/kexin type-9 concentration and paraoxonase 1 activities in the blood of women with polycystic ovary syndrome

•For the first time, the serum PCSK9 concentration of Caucasian women with PCOS was determined.•The women with PCOS were characterized by higher PCSK9 and lower HDL concentration than women without PCOS.•The serum PCSK9 concentration in the group with PCOS could be associated with androgens and insulin level.•Significant changes in serum paraoxonase activities were detected between women with and without PCOS.