New research on cholesterol shows that ‘good cholesterol’ is not all good for the heart – only smaller particles reduce heart risk.
Higher levels of ‘good cholesterol’ or high-density lipoprotein cholesterol (HDL-c ) have been associated with better cardiovascular outcomes. In contrast, ‘bad cholesterol’ or low-density lipoprotein cholesterol (LDL-c ), deposits cholesterol on artery walls, increasing the risk of cardiovascular disease.
Medications that lowers LDL-c also reduce cardiovascular risk, but medication that increases HDL-c does not decrease cardiovascular risk. This paradox calls into question the assumption that HDL-c is protective against cardiovascular risk.
Researchers analysed the size of HDL-c particles, which is determined by genetic characteristics, and compared this to the risk of myocardial infarction. The results showed that genetic characteristics for having large HDL-c particles were associated with increased heart attack risk. Characteristics for smaller HDL-c particles were linked to reduced heart attack risk.
“There is a positive causal relationship between the size of HDL cholesterol particles and the risk of heart attack, so although we have to increase the levels of good cholesterol in the blood, they must always be small particles,” explains the study’s principal investigator, Dr Robert Elosua, a researcher at the Hospital del Mar-IMIM, CIBERCV, and the University of Vic-Central University of Catalonia.
The HDL-c particles are more effective in transferring cholesterol to the liver for subsequent elimination. “If we need to do something in relation to HDL, it is to increase the number of small particles, which are those that adequately perform the function of eliminating cholesterol, those that really move it to the liver for removal, and do not allow it to accumulate in the arteries and cause cardiovascular disease,” said Dr Álvaro Hernáez.
There are currently no drugs that increase HDL-c and also reduce cardiovascular risk. “This study highlights new and potential therapeutic targets in the field of cardiovascular diseases, including several genes related to the qualitative aspects of HDL particles, which may contribute to cardiovascular prevention,” concluded first author Dr Albert Prats.
Source: Medical Xpress
Journal information: Albert Prats-Uribe et al, High-density lipoprotein characteristics and coronary artery disease: a Mendelian randomization study, Metabolism (2020). DOI: 10.1016/j.metabol.2020.154351
