Non-cholesterol sterols and cholesterol metabolism in sitosterolemia

Atherosclerosis. 2013 Dec;231(2):291-9. doi: 10.1016/j.atherosclerosis.2013.09.038. Epub 2013 Oct 10.


Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.

Keywords: ABCG5/8; Atherosclerosis; Cholesterol; HMG CoA reductase; NPC1L1; Non-cholesterol sterols; Plant sterols; SOAT2; Xanthoma.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily G
  • ATP-Binding Cassette Transporters / metabolism
  • Absorption
  • Atherosclerosis / drug therapy*
  • Azetidines / pharmacology*
  • Cholesterol / blood*
  • Cholesterol / metabolism
  • Disease Progression
  • Ezetimibe
  • Humans
  • Hypercholesterolemia / blood
  • Hypercholesterolemia / metabolism*
  • Intestinal Diseases / blood
  • Intestinal Diseases / metabolism*
  • Kinetics
  • Lipid Metabolism, Inborn Errors / blood
  • Lipid Metabolism, Inborn Errors / metabolism*
  • Membrane Proteins / metabolism
  • Membrane Transport Proteins
  • Phytosterols / adverse effects*
  • Phytosterols / blood
  • Phytosterols / metabolism
  • Sitosterols / blood
  • Sterol O-Acyltransferase / metabolism
  • Sterols / blood*
  • Sterols / metabolism
  • Xanthomatosis / drug therapy*


  • ABCG4 protein, human
  • ATP Binding Cassette Transporter, Subfamily G
  • ATP-Binding Cassette Transporters
  • Azetidines
  • Membrane Proteins
  • Membrane Transport Proteins
  • NPC1L1 protein, human
  • Phytosterols
  • Sitosterols
  • Sterols
  • Cholesterol
  • Sterol O-Acyltransferase
  • sterol O-acyltransferase 2
  • Ezetimibe

Supplementary concepts

  • Sitosterolemia