Cholesterol is a type of lipid which is incorporated into cell membranes and used in the synthesis of steroid hormones. It can also accumulate in the walls of arteries, resulting in atherosclerosis. Atherosclerosis causes arteries to become stiff and narrow and increases the risk of coronary heart disease and a stroke. Not all forms of cholesterol contribute to atherosclerosis-- some can protect against this disease.
Lipoproteins
Cholesterol does not float freely in the blood; instead it is packaged with proteins and other lipids to form molecules known as lipoproteins. Some lipoproteins, such as low-density lipoprotein or LDL, can result in an increased risk of atherosclerosis. High-density lipoproteins, also known as HDL, prevent atherosclerosis. As a result, cholesterol which is packaged into HDL molecules is typically termed "good" cholesterol.
Testing
HDL cholesterol levels are typically measured as part of a comprehensive examination of the lipids in the blood known as a lipid profile, Lab Tests Online notes. A lipid profile requires a blood sample which is usually taken from a vein, though a sample from a pricking a finger may also be used. A lipid profile involves testing the levels of HDL and LDL cholesterol as well as another type of lipid known as triglycerides, which can also increase your risk of cardiovascular disease. Lipid profiles may be performed as part of a routine checkup and are especially important in patients who have a high risk of a heart attack or who are being treated for high cholesterol levels.
Results
HDL cholesterol levels of greater than 60mg/dL are associated with a below-average risk of developing heart disease, Lab Tests Online reports. The typical level of HDL cholesterol is between 40 and 50mg/dL for men and between 50 and 59 mg/dL for women. Measurements below that are considered to put a patient at a greater risk of developing heart disease.
Lifestyle Effects
Certain lifestyle factors increase your risk of having low HDL levels, MayoClinic.com explains. Being overweight typically lowers your HDL counts, though losing excess body fat can cause HDL levels to rise. A diet which is high in fat, particularly saturated and trans fats can also result in decreased HDL levels as well as increased LDL and triglyceride levels. A lack of physical activity is also associated with low HDL levels.
Medications For Raising HDL
In addition to reducing the amount of saturated and trans fats in the diet and exercising, patients can also take medications to increase their HDL levels. Niacin is the most effective drug for increasing HDL counts. Statins and fibrates, two other medications which are often prescribed for treating poor cholesterol levels, can also increase HDL concentrations in the blood.
