Does having high HDL cholesterol lower my atherosclerosis risk?

HDL cholesterol is often called 'good' cholesterol because higher levels have been linked to lower heart disease risk in population studies. However, the picture is more complicated than 'high HDL always protects against atherosclerosis.' Some research shows that having naturally high HDL is associated with less plaque buildup, but clinical trials that tried to raise HDL with medications did not always lower heart attack or stroke risk. This suggests that HDL's role in atherosclerosis depends on factors like how it functions, not just its blood level.

What the research says

A large Chinese study of over 12,000 people found that those with HDL cholesterol above 1.55 mmol/L had a 20% lower chance of having carotid plaque, a sign of atherosclerosis, compared to those with lower HDL ⁶. This supports the idea that higher HDL is linked to less plaque. However, the same study noted that female sex was also protective, showing that other factors matter ⁶.

On the other hand, a major clinical trial tested whether raising HDL with niacin (a B vitamin) would reduce cardiovascular events in people already taking statins. Even though niacin raised HDL levels significantly, the trial was stopped early because it did not reduce heart attacks, strokes, or deaths ¹⁰. This shows that simply increasing HDL numbers may not translate into lower risk.

More recent research has focused on HDL function rather than just its level. For example, a review of macrophage states in atherosclerosis suggests that how HDL interacts with immune cells in the plaque may be more important than the amount in the blood ⁵. Additionally, a trial of a newer drug called obicetrapib, which raises HDL by blocking a protein, is still being studied for its effects on cardiovascular outcomes ⁹. So far, the evidence is mixed, and experts agree that the relationship between HDL and atherosclerosis is not straightforward.

What to ask your doctor

• Should I focus on my HDL level or on other lipid numbers like LDL and triglycerides?
• Are there lifestyle changes that can improve HDL function, not just raise the number?
• Given my personal risk factors, what is the best way to monitor my atherosclerosis risk?
• Do the latest studies on HDL-raising drugs apply to my situation?
• How do my other health conditions affect the interpretation of my HDL level?