Which of the following markers is often associated with heart disease risk?

Low-density lipoprotein (LDL) is often referred to as "bad" cholesterol, and it is a key marker associated with heart disease risk. Elevated levels of LDL cholesterol can lead to the buildup of fatty deposits (plaque) in the walls of arteries, which can result in atherosclerosis, a condition that narrows and hardens the arteries and increases the risk of heart attacks and strokes. Therefore, monitoring and managing LDL levels is an important aspect of heart disease prevention and management.

While high-density lipoprotein (HDL) is considered "good" cholesterol that helps remove LDL from the bloodstream, and hemoglobin A1c is a measure of blood sugar levels over time which is relevant for diabetes rather than directly for heart disease, and C-reactive protein is a marker of inflammation that can also indicate heart disease risk but is not a direct cholesterol measure. The focus on LDL underlines its significant role in cardiovascular health, making it a primary target for interventions to reduce heart disease risk.