Simvastatin reduces circulating oxysterol levels in men with hypercholesterolaemia

Area of Science:

• Biochemistry and Metabolism
• Cardiovascular Research
• Pharmacology

Background:

• Oxysterols, cholesterol metabolites, have varied biological effects and are implicated in diseases.
• Analysis of free oxysterols is challenging due to methodological limitations.
• Elevated oxysterols, particularly those from autoxidation, may be linked to hypercholesterolemia.

Purpose of the Study:

• To develop a sensitive LC-MS/MS method for quantifying five key plasma oxysterols.
• To investigate if simvastatin reduces specific plasma free oxysterol concentrations in hypercholesterolemia.

Main Methods:

• Developed and validated a quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.
• Recruited 20 healthy male volunteers (10 hypercholesterolemic, 10 normal cholesterol).
• Administered simvastatin (40 mg/day) to hypercholesterolemic group and collected plasma samples at baseline and 3 months.

Main Results:

• Simvastatin significantly reduced plasma cholesterol by approximately 35% in the hypercholesterolemic group.
• Autoxidation-derived oxysterols were significantly elevated (up to 45-fold) in hypercholesterolemic men.
• Simvastatin treatment restored plasma oxysterol levels to those observed in healthy controls.

Conclusions:

• Simvastatin effectively lowers plasma cholesterol and reduces elevated levels of autoxidation-derived oxysterols.
• The findings suggest simvastatin may prevent cholesterol autoxidation or reduce its prevalence.
• This normalization of oxysterols by simvastatin may contribute to its cardiovascular benefits.