Long-term Benefits and Harms Associated With Genetic Cholesteryl Ester Transfer Protein Deficiency in the General Population

This cohort study assesses the relative benefits and harms associated with genetic cholesteryl ester transfer protein deficiency. Question What is the balance between the long-term clinical benefits and harms associated with genetic cholesteryl ester transfer protein (CETP) deficiency? Findings This cohort study of the Danish general population found that genetic CETP deficiency was associated with lower risk of cardiovascular morbidity and mortality but higher risk of age-related macular degeneration (AMD). The lower risk of cardiovascular end points was associated with genetically lower levels of non-high density lipoprotein (HDL) cholesterol, while the higher risk of AMD was associated with genetically higher levels of HDL cholesterol. Meaning Despite a beneficial association between genetic CETP deficiency and cardiovascular outcomes, the increased risk of AMD may call into question the use of pharmacologic CETP inhibitors. IMPORTANCE The balance between the potential long-term clinical benefits and harms associated with genetic cholesteryl ester transfer protein (CETP) deficiency, mimicking pharmacologic CETP inhibition, is unknown. OBJECTIVE To assess the relative benefits and harms associated with genetic CETP deficiency. DESIGN, SETTING, AND PARTICIPANTS This study examined 2 similar prospective cohorts of the Danish general population, with data on a total of 102 607 participants collected from October 10, 1991, through December 7, 2018. EXPOSURES Weighted CETP allele scores. MAIN OUTCOMES AND MEASURES Incident cardiovascular mortality, ischemic heart disease, myocardial infarction, ischemic stroke, peripheral arterial disease, vascular dementia, Alzheimer disease, all-cause mortality, and age-related macular degeneration (AMD). The study first tested whether a CETP allele score was associated with morbidity and mortality, when scaled to genetically lower levels of non-high-density lipoprotein (HDL) cholesterol (ie, 17 mg/dL), corresponding to the reduction observed for anacetrapib vs placebo in the Randomized Evaluation of the Effects of Anacetrapib Through Lipid-Modification (REVEAL) trial. Second, the study assessed how much of the change in morbidity and mortality was associated with genetically lower levels of non-HDL cholesterol. Finally, the balance between the potential long-term clinical benefits and harms associated with genetic CETP deficiency was quantified. For AMD, the analyses also included higher levels of HDL cholesterol associated with genetic CETP deficiency. RESULTS Of 102 607 individuals in the study, 56 559 (55%) were women (median age, 58 years [IQR, 47-67 years]). Multivariable adjusted hazard ratios showed that a genetically lower level of non-HDL cholesterol (ie, 17 mg/dL) was associated with a lower risk of cardiovascular mortality (hazard ratio [HR], 0.77 [95% CI, 0.62-0.95]), ischemic heart disease (HR, 0.80 [95% CI, 0.68-0.95]), myocardial infarction (HR, 0.72 [95% CI, 0.55-0.93]), peripheral arterial disease (HR, 0.80 [95% CI, 0.63-1.02]), and vascular dementia (HR, 0.38 [95% CI, 0.18-0.80]) and an increased risk of AMD (HR, 2.33 [95% CI, 1.63-3.30]) but was not associated with all-cause mortality (HR, 0.91 [95% CI, 0.81-1.02]), ischemic stroke (HR, 1.05 [95% CI, 0.81-1.36]), or Alzheimer disease (HR, 1.25 [95% CI, 0.89-1.76]). When scaled to a higher level of HDL cholesterol, the increased risk of AMD was even larger. A considerable fraction of the lower risk of cardiovascular end points was associated with genetically lower levels of non-HDL cholesterol, while the higher risk of AMD was associated with genetically higher levels of HDL cholesterol. Per 1 million person-years, the projected 1916 more AMD events associated with genetically higher levels of HDL cholesterol was similar to the 1962 fewer events of cardiovascular mortality and myocardial infarction combined associated with genetically lower levels of non-HDL cholesterol. CONCLUSIONS AND RELEVANCE This study suggests that genetic CETP deficiency, mimicking pharmacologic CETP inhibition, was associated with a lower risk of cardiovascular morbidity and mortality, but with a markedly higher risk of AMD.