Raising ’good’ cholesterol fails to protect against heart disease

Raising so-called 'good' cholesterol by blocking a key protein involved in its metabolism does not protect against heart disease or stroke, according to a large genetic study of 150,000 Chinese adults published in the journal JAMA Cardiology. There are two types of cholesterol in the blood: LDL-C, so-called 'bad' cholesterol, which is carried in low-density lipoproteins (LDL), and HDL-C, so-called 'good' cholesterol which is found in high-density lipoproteins (HDL). Lowering LDL-C (e.g. by statins) has been demonstrated to reduce the risk of heart diseases and stroke, but the causal role of HDL-C is less clear even though observational studies have shown an inverse association between HDL-C and risk of cardiovascular diseases. Cholesterol ester transfer protein (CETP) transfers cholesterol between different lipoproteins. Blocking this protein, which raises levels of HDL-C as well as causing other changes to blood lipids, is a potentially important approach for prevention and treatment of cardiovascular diseases. Genetic variants which alter the activity of CETP can mimic some of the effects of drugs which target this protein and can be used to help assess the potential benefits and harms of this cholesterol-modifying treatment.