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Genetic inhibition of CETP, ischemic vascular disease and mortality, and possible adverse effects
Trine Holm Johannsen1, Ruth Frikke-Schmidt, Jesper Schou
1Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.
Objectives:
This study tested whether genetic variation in the CETP gene is consistent with a protective effect of cholesteryl ester transfer protein (CETP) inhibition on risk of ischemic events and on total mortality, without the adverse effects reported for torcetrapib.
Background:
Torcetrapib, an inhibitor of CETP, increased risk of death and ischemic cardiovascular disease of those randomized to the drug, despite improving the lipid profile.
Methods:
The Copenhagen City Heart Study is a prospective cohort study of 10,261 individuals, aged 20 to 93 years, who were followed for up to 34 years (1976 to 2010). Of these, 2,087 developed ischemic heart disease, 1,064 developed ischemic cerebrovascular disease, and 3,807 died during follow-up. We selected 2 common genetic variants in CETP previously associated with reductions in CETP activity, thus mimicking the effect of pharmacological CETP inhibition.
Results:
In individuals carrying 4 versus 0 high-density lipoprotein cholesterol-increasing alleles, there was an increase in levels of high-density lipoprotein cholesterol of up to 14% (0.2 mmol/l), and concomitant decreases in triglycerides, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol of, respectively, 6% (0.1 mmol/l), 3% (0.1 mmol/l), and 4% (0.2 mmol/l) (p for trend 0.004 to <0.001). Corresponding hazard ratios were 0.76 (95% confidence interval [CI]: 0.68 to 0.85) for any ischemic vascular event, 0.74 (95% CI: 0.65 to 0.85) for ischemic heart disease, 0.65 (95% CI: 0.54 to 0.79) for myocardial infarction, 0.77 (95% CI: 0.65 to 0.93) for ischemic cerebrovascular disease, 0.71 (95% CI: 0.58 to 0.88) for ischemic stroke, and 0.88 (95% CI: 0.80 to 0.97) for total mortality. CETP genotypes did not associate with variation in markers of possible side effects previously reported for torcetrapib.
Conclusions:
Genetic CETP inhibition associates with reductions in risk of ischemic heart disease, myocardial infarction, ischemic cerebrovascular disease, and ischemic stroke, with a corresponding antiatherogenic lipid profile, and with increased longevity, without adverse effects.
Insights
Genetic cholesteryl ester transfer protein (CETP) inhibition is linked to reduced risk of ischemic events and mortality. This protective effect occurs without the adverse effects seen with torcetrapib.
Area of Science:
- Cardiovascular Genetics
- Pharmacogenomics
- Lipid Metabolism
Background:
- Torcetrapib, a cholesteryl ester transfer protein (CETP) inhibitor, increased mortality and ischemic cardiovascular disease risk despite lipid profile improvements.
- Adverse effects of torcetrapib necessitate investigation into alternative CETP inhibition strategies.
Purpose of the Study:
- To investigate the association between genetic variation in the CETP gene and the risk of ischemic events and total mortality.
- To determine if genetic CETP inhibition confers a protective effect without the adverse effects observed with torcetrapib.
Main Methods:
- Prospective cohort study (Copenhagen City Heart Study) of 10,261 individuals followed for up to 34 years.
- Analysis of two common genetic variants in CETP associated with reduced CETP activity, mimicking pharmacological inhibition.
- Assessment of ischemic vascular events, myocardial infarction, ischemic cerebrovascular disease, ischemic stroke, and total mortality.
Main Results:
- Individuals with 4 high-density lipoprotein cholesterol-increasing alleles showed a 14% increase in HDL-C and decreases in triglycerides and LDL-C.
- Significant reductions in hazard ratios were observed for ischemic vascular events (0.76), ischemic heart disease (0.74), myocardial infarction (0.65), ischemic cerebrovascular disease (0.77), and ischemic stroke (0.71).
- Total mortality was reduced (hazard ratio 0.88), and CETP genotypes did not associate with markers of torcetrapib's adverse effects.
Conclusions:
- Genetic CETP inhibition is associated with reduced risk of major ischemic vascular diseases and increased longevity.
- The observed antiatherogenic lipid profile supports a protective role for CETP inhibition.
- Genetic CETP inhibition offers a potential therapeutic strategy without the adverse effects linked to torcetrapib.
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