Cholesterol cannot dissolve in blood, and must be transported to and from cells by lipoproteins, according to the American Heart Association. Low-density lipoproteins, or LDL, and high-density lipoproteins, or HDL, transport cholesterol throughout the body. The American Heart Association considers LDL "bad" cholesterol, and HDL "good" cholesterol. High levels of HDL and low levels of LDL contribute to a healthy lifestyle.
Function
A total cholesterol count measures LDL and HDL among others. LDL makes up most of the body's cholesterol. High levels of LDL cause a buildup of plaque in the arteries that can lead to heart disease, according to the Centers for Disease Control and Prevention. HDL works to absorb cholesterol and carry it back to the liver, from which the body removes it. The CDC reports that high levels of HDL reduce the risk of heart disease.
Significance of LDL Value
The optimal level for LDL is lower than 100 ng/dL, according to the National Cholesterol Education Program. Elevated levels of LDL are a major cause of heart disease in the United States, according to the Cleveland Clinic. The Cleveland Clinic recommends an LDL lower than 70 ng/dL for those with heart or blood vessel disease or high risk of heart disease. The cholesterol guidelines established by the National Cholesterol Education Program set as optimal LDL levels of 100 to 129 ng/dL, with 130 to 159 ng/dL borderline high and 160 to 189 ng/dL high. A reading above 190 ng/dLrepresents very high LDL and carries significant risk of heart disease.
Significance of HDL Value
HDL carries approximately one-fourth to one-third of the blood's total cholesterol, according to the American Heart Association. The cholesterol guidelines of the National Cholesterol Education Program set as optimal an HDL level greater than or equal to 60 ng/dL optimal. This level helps reduce the risk of heart disease. A suboptimal HDL level, of less than 40, places both men and women at increased risk for heart disease, based on the guidelines from the National Cholesterol Education Program.
Monitoring HDL and LDL
The National Cholesterol Education Program recommends checking cholesterol level at least once every five years for all adults over the age of 20. The guidelines recommend having a complete lipoprotein profile that measures total cholesterol, LDL, HDL and triglycerides, another type of fat in the bloodstream, according to the National Cholesterol Education Program.
Prevention/Solution
The guidelines established by the National Cholesterol Education Program in 2002 emphasize maintaining optimal HDL and LDL levels to prevent heart disease. The Cleveland Clinic recommends "therapeutic lifestyles changes" to lower harmful levels of LDL. Lifestyle recommendations include reducing saturated fat and cholesterol intake, increasing intake of fiber, maintaining a healthy weight, increasing physical activity, controlling blood pressure and quitting smoking. Work with your doctor to create a heart-healthy lifestyle.
References
- Centers for Disease Control and Prevention: Cholesterol
- Cleveland Clinic Miller Family Heart and Vascular Institute: Heart and Vascular Health and Prevention
- American Heart Association: Good vs. Bad Cholesterol
- National Cholesterol Education Program: Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol
