Serum proprotein convertase subtilisin/kexin type 9 concentration is not increased by plant stanol ester consumption in normo- to moderately hypercholesterolaemic non-obese subjects. The BLOOD FLOW intervention study.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates low-density lipoprotein (LDL) cholesterol (LDL-C) metabolism by targeting LDL receptors for degradation. Statins increase serum PCSK9 concentration limiting the potential of statins to reduce LDL-C, whereas ezetimibe, inhibitor of cholesterol absorption, has ambiguous effects on circulating PCSK9 levels. Plant stanols also reduce cholesterol absorption, but their effect on serum PCSK9 concentration is not known. Therefore, we performed a controlled, randomized, double-blind study, in which 92 normo- to moderately hypercholesterolaemic subjects (35 males and 57 females) consumed vegetable-oil spread 20 g/day enriched (plant stanol group, n=46) or not (control group, n=46) with plant stanols 3 g/day as ester for 6 months. Fasting blood samples were drawn at baseline and at the end of the study. Serum PCSK9 concentration was analysed with Quantikine Elisa Immunoassay, serum and lipoprotein lipids enzymatically and serum non-cholesterol sterols with GLC. At baseline, PCSK9 concentration varied from 91 to 716 ng/ml with a mean value of 278±11 (S.E.M.) ng/ml with no gender difference. It correlated with serum and LDL-C, serum triglycerides, age, body mass index (BMI) and plasma glucose concentration, but not with variables of cholesterol metabolism when adjusted to serum cholesterol. Plant stanols reduced LDL-C by 10% from controls (P