Association of Genetic Variants Related to CETP Inhibitors and Statins With Lipoprotein Levels and Cardiovascular...

Area of Science:

• Cardiovascular Genetics and Lipid Metabolism

Background:

• Cholesteryl ester transfer protein (CETP) inhibitors lower low-density lipoprotein cholesterol (LDL-C) but do not always reduce cardiovascular events.
• This suggests that the method of LDL-C reduction influences clinical benefit, potentially related to other lipoprotein changes.

Purpose of the Study:

• To investigate the association between genetic variants in CETP and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) genes.
• To estimate the relationship between changes in LDL-C, other lipoproteins (like apoB), and cardiovascular event risk.

Main Methods:

• Mendelian randomization analyses were performed on over 100,000 participants from North American and UK studies.
• Associations were evaluated for CETP and HMGCR genetic scores, lipid levels, and cardiovascular event risk.
• External validation was conducted using data from nearly 190,000 participants across multiple studies.

Main Results:

• CETP variants alone were associated with higher HDL-C, lower LDL-C and apoB, and reduced cardiovascular event risk.
• Combined CETP and HMGCR variants showed similar LDL-C reduction but less apoB reduction, leading to an attenuated, non-significant risk reduction.
• External validation confirmed that genetic scores with discordant LDL-C and apoB changes had attenuated cardiovascular risk reduction per LDL-C unit compared to concordant scores.

Conclusions:

• Combined genetic influences on CETP and HMGCR pathways lead to discordant changes in LDL-C and apoB levels.
• The cardiovascular risk reduction associated with lipid-lowering strategies may be more closely tied to the reduction in apoB-containing particles than LDL-C alone.
• Clinical benefit of lowering LDL-C may depend on the concurrent reduction in apolipoprotein B.