In order to move through your bloodstream, cholesterol, fat and some proteins need certain carriers called lipoproteins. Cholesterol tests often measure the amount of specific lipoproteins in the blood, and this measurement indirectly reveals the level of cholesterol in your blood. However, lipoproteins also carry other substances besides cholesterol. Understanding the difference between two lipoproteins, LDL and VLDL, can help you better comprehend any cholesterol tests you undergo.
Lipoproteins are particles that allow fat-soluble molecules, such as cholesterol and fat, to move through the watery environment of your bloodstream. Lipoproteins consist of a core of cholesterol and fat, surrounded by phospholipids and protein, according to the University of Washington. This structure separates the insoluble core material from the outside environment. Lipoproteins are categorized depending on the amount of cholesterol and fats they carry. Some examples of lipoproteins include low-density lipoprotein, or LDL, and very-low-density lipoprotein, or VLDL.
Very-low-density lipoprotein, VLDL, is rarely reported on a cholesterol test because it does not contain substantial amounts of cholesterol. Instead, VLDL is filled with triglycerides, which are a form of fat commonly seen in the bloodstream, Mayo Clinic reports. Thus, by measuring VLDL levels in the blood, doctors are able to indirectly ascertain the amount of fat circulating in your bloodstream. Normal values for VLDL in the blood range from 5 to 40 mg/dL
The term LDL, or low-density lipoprotein, is more commonly known than VLDL. Levels of LDL, also known as “bad cholesterol,” are often reported in a routine cholesterol test. Instead of containing large amounts of triglycerides, LDL carries a majority of your body's cholesterol. LDL can build up in the blood and cause disease and complications. For people at risk for heart disease, an LDL level below 100 mg/dL is optimal. FamilyDoctor.org says. Any LDL value between 100 to 129 mg/dL is near optimal, while 130 to 159 is labeled as borderline high. An LDL value of 160 or greater places you in the high-risk category.
High VLDL and LDL Levels
High levels of VLDL and LDL often correlate with disease. Though both lipoproteins carry different molecules, high levels often lead to heart or blood vessel disease. High VLDL levels are often associated with coronary artery disease, which is a condition caused by occlusion of the vessels supplying the heart with blood. Coronary artery disease can lead to heart attacks and stroke, Mayo Clinic warns.
High LDL levels typically mean high cholesterol levels. LDL particles can build up in the bloodstream and then enter the walls of the blood vessels. Once in the walls, LDL forms a plaque that causes the arteries to harden and narrow. This is called atherosclerosis. Atherosclerosis can lead to an increase in blood pressure and heart disease, according to the Centers for Disease Control and Prevention.