You may already know about "good cholesterol," or HDL-C, versus "bad cholesterol," or LDL-C. And, in general, this is a good way to think about cholesterol types: high LDL-C and low HDL-C tend to go together, and this profile puts you at increased risk of having a heart attack. When looking specifically at HDL-C levels, higher HDL-C levels are generally considered a good thing, however your genes and other factors may have a lot to do with the ultimate effect of increasing HDL levels. Have your cholesterol checked by a physician, who can review the numbers and make recommendations.
Cholesterol is transported through the body by special carriers. One type of carrier is low-density lipoprotein, which is considered the "bad" kind, because it delivers cholesterol to the cells and arterial lining. When LDL-C gets too high, plaque can build up along the blood vessel walls and cause atherosclerosis, also called coronary artery disease when it occurs in the heart's blood supply. The other main type of carrier is HDL, which is the "good" kind, because it picks up LDL-C and shuttles it away from the arteries and to the liver, where it can be eliminated from the body. If your total cholesterol is under 200 mg/dL, but your HDL levels are under 40 mg/dL, your risk for heart disease is greater than someone with the same total cholesterol but higher HDL-C. But the reasons for this are complex.
The HDL Puzzle
The protective effect of HDL-C against artery disease is seen in studies showing that HDL of 75 mg/dL or higher are associated with prolonged life and low rates of coronary heart disease. Low HDL-C levels, however, can occur alone or, more typically, together with elevated LDL and triglycerides. In some groups of people, the risk from having a low HDL is not as impressive if you adjust for other factors like LDL concentrations. Furthermore, evidence suggests that portions of the population may be affected differently by higher or lower HDL levels relative to their LDL levels. Not all studies have found that HDL predicts future heart attacks in patients with heart disease treated with statins.
Even though raising the HDL doesn't necessarily "cause" fewer heart attacks, higher HDL-C levels are associated with a protective effect. Aiming for an HDL level of 60 mg/dL or higher is a general goal that may be appropriate for many different types of patients. A physician will need to review your individual overall health to determine your actual risk for heart disease. Because each case is different, always talk with a physician about high HDL levels, as genetic factors, illnesses, and various other conditions may be associated with abnormal HDL-C levels.
HDL-C levels are important for a variety of reasons. Higher levels of this "good" cholesterol are generally associated with less cardiovascular risk. However, the levels of LDL-C factor into this equation as well -- as do other biological markers, genes, and elements from your medical history. Thus, for a complete and comprehensive assessment of your cardiovascular risk, work with your doctor, who can then make recommendations to appropriately manage your risk.