[Blood Levels of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in Men from Different Population Groups and Its Relation to Unfavorable Long-Term Prognosis].

AIM: of the study was to investigate blood levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) in men from different population subgroups, their associations with cardiovascular risk factors and with unfavorable 7-years long-term prognosis. MATERIAL AND METHODS: The study included three subgroups of men from a population sample of residents of Novosibirsk, 44-73 years old, not receiving lipid-lowering drugs: subgroup of population proper (183 men), subgroup with hypercholesterolemia (46 men), and subgroup with hypocholesterolemia (18 men). Blood level of PCSK9 was determined by ELISA using the test-systems "Human Proprotein Convertase 9/PCSK9 Immunoassay". Study endpoints (myocardial infarction, cardiovascular death) were registered during 7 years after baseline examination of subgroups using the data of the Registers of myocardial infarction and cardiovascular mortality. RESULTS: Distribution of PCSK9 protein in subgroups with hyper- and hypocholesterolemia was normal. In the subgroup of population proper it was abnormal with leftward shift. PCSK9 protein concentration in the subgroup with hypercholesterolemia was 1.2 times higher than in the population subgroup. PCSK9 protein level correlated significantly with blood levels of total cholesterol (CH), low density lipoprotein (LDL) CH, and glucose. Only 15% of PCSK9 variability was due to the influence of other factors (R Square=0.155, p<0.001). Factors with significant influence on blood level of PCSK9 protein were levels of high density lipoprotein CH (=0.238, p=0.023), triglycerides (=0.253, p=0.049) and LDL CH (=0.751, p=0.009). Multivariate regression analysis revealed significant independent association of PCSK9 protein levels with cardiovascular death during period of registration (7-years) (p=0.048, OR=1.01). This result indicates that in men increase of blood level of PCSK9 protein by 1ng/ml independently of other parameters increases relative risk of cardiovascular death during following 7 years by 1%.