תזונה ותוספים Fasting reduces plasma proprotein convertase, subtilisin/kexin type 9 and cholesterol

[Mike Bikov]

J Lipid Res. 2010 Aug 16. [Epub ahead of print]
Fasting reduces plasma proprotein convertase, subtilisin/kexin type 9 and cholesterol biosynthesis in humans.

Browning JD, Horton JD.

University of Texas Southwestern Medical Center, United States.
Abstract

Proprotein convertase, subtilisin/kexin type 9 (PCSK9), a key regulator of plasma LDL-cholesterol (c) and cardiovascular risk, is produced in liver and secreted into plasma where it binds hepatic LDL receptors (LDLR), leading to their degradation. PCSK9 is transcriptionally activated by sterol response element-binding protein (SREBP)-2, a transcription factor that also activates all genes for cholesterol synthesis as well as the LDLR. Here we investigated the relationship between plasma PCSK9 levels and the lathosterol-to-cholesterol ratio, a marker of cholesterol biosynthesis, in 18 healthy subjects during a 48 hr fast. In all individuals, plasma PCSK9 levels declined steadily during the fasting period, reaching a nadir at 36 hrs that was ~58% lower than levels measured in the fed state (P<0.001). Similarly, the lathosterol-to-cholesterol ratio declined in parallel with plasma PCSK9 concentrations during the fast, reaching a nadir at 36 hrs that was ~28% lower than that measured in the fed state (P=0.024). In summary, fasting has a marked effect on plasma PCSK9 concentrations, which is mirrored by measures of cholesterol synthesis in humans. Inasmuch as cholesterol synthesis and PCSK9 are both regulated by SREBP-2, these results suggest that plasma PCSK9 levels may serve as a surrogate marker of hepatic SREBP-2 activity in humans.

PMID: 20716520 [PubMed - as supplied by publisher]​

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