It’s true – too much of a good thing can sometimes be a bad thing. Take high-density lipoproteins, or “good” cholesterol.

Researchers have discovered that certain components of high-density lipoproteins (HDL) may be associated with an increased prevalence of cardiovascular disease.

“During routine checkups, adults have their cholesterol levels tested, which includes both ‘bad’ (LDL) and ‘good’ (HDL) cholesterol,” said study co-author Henry J. Pownall, PhD. “Not all cholesterol, however, is born the same. What is not commonly recognized is that each type of cholesterol has two forms—free cholesterol, which is active and involved in cellular functions, and esterified, or bound, cholesterol, which is more stable and ready to be stored in the body. Too much free cholesterol, even if it is in HDL, could contribute to heart disease.”

In pre-clinical studies, the research team discovered that HDL with a high content of free cholesterol is likely dysfunctional. To validate their findings and prove their hypothesis, they are currently at the halfway point of the NIH-funded Houston Heart Study.

“The most surprising finding from our study thus far is that there is a strong link between the amount of free cholesterol in HDL and how much of it accumulates in white blood cells called macrophages, which can contribute to heart disease,” Pownall said.

While it was previously thought that the transfer of free cholesterol to HDL was beneficial for heart health by removing excess cholesterol from tissues, Pownall said their data shows that in the context of high plasma HDL concentrations, the reverse is true, wherein free cholesterol transfer from HDL to the white blood cells in blood and tissues could raise one’s risk for cardiovascular disease.

The researchers stated once they reach their immediate goal of showing that excess free cholesterol in HDL is associated with excess cardiovascular disease, they plan to develop new diagnostics and treatments for managing heart disease, as well as use HDL-free cholesterol as a biomarker to identify patients requiring HDL-lowering therapies.

“We anticipate being able to reach our first goal in less than three years, as there are some known drugs that affect free cholesterol in pre-clinical models, so this could be tested in humans if our tests justify the use of these known therapeutics,” Pownall said. If they are successful, Pownall proposes that they could potentially be able to apply what they learn to patients in a clinical setting as quickly as six years from now.

Reference:

https://www.sciencedaily.com/releases/2024/12/241219152801.htm

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