Which of the following statements regarding lipoproteins & CVD is true?

• A. Increased HDL levels & decreased LDL levels are both risk factors for CVD.
• B. VLDLs can directly cause CVD when they are deposited on blood vessel walls.
• C. VLDLs can indirectly cause CVD, because they develop into LDLs which could the deposit cholesterol on blood vessel walls, causing them to narrow.
• D. While scientists believe there is a link between lipoprotein levels & associated risk of heart disease, there is still not enough conclusive evidence.

Answer: (C)

Verified step by step guidance

1. Understand the role of lipoproteins in cardiovascular disease (CVD). Lipoproteins are molecules that transport lipids (fats) in the blood. The main types include HDL (high-density lipoprotein), LDL (low-density lipoprotein), and VLDL (very low-density lipoprotein). Each has a different impact on heart health.
2. Analyze the relationship between HDL and CVD. HDL is often referred to as 'good cholesterol' because it helps remove cholesterol from the bloodstream and transport it to the liver for excretion. Higher levels of HDL are generally associated with a lower risk of CVD.
3. Examine the role of LDL in CVD. LDL is known as 'bad cholesterol' because it can deposit cholesterol on the walls of blood vessels, leading to plaque formation, narrowing of arteries, and an increased risk of CVD. Higher levels of LDL are a significant risk factor for heart disease.
4. Understand the function of VLDL. VLDL primarily transports triglycerides in the blood. While VLDL itself does not directly cause CVD, it can be converted into LDL in the bloodstream. This conversion increases the levels of LDL, which can then contribute to cholesterol deposition and arterial narrowing.
5. Evaluate the scientific consensus. While there is strong evidence linking lipoprotein levels (especially LDL and HDL) to CVD risk, ongoing research is needed to fully understand the mechanisms and establish conclusive evidence. This highlights the complexity of the relationship between lipoproteins and heart disease.