Cholesterol Blood Levels - LDL and HDL - normal and high
What is Cholesterol Blood Levels
Cholesterol Blood Levels - the amounts and forms of cholesterol that are present in the bloodstream, usually measured after 8 to 12 hours of fasting (no food) to accommodate short-term rises that could result from eating. Cholesterol is a sterol, a chemical essential for numerous metabolic functions and necessary for health. Because cholesterol cannot dissolve in the BLOOD, it binds with protein carriers called lipoproteins that suspend it in the blood. Cholesterol becomes a health problem when the amount of cholesterol in the blood circulation exceeds the body’s needs. The excess lipoproteins that transport the cholesterol fall out of suspension and infiltrate the inner lining of the arterial walls, forming ATHEROSCLEROTIC PLAQUE. Health factors that increase the risk of elevated lipoprotein-cholesterol blood levels include OBESITY, DIABETES, and HYPERTENSION.
| Cholesterol Blood Levels and Cardiovascular Health | ||||
|---|---|---|---|---|
| Cholesterol | Optimal | Moderate Risk | High Risk | |
| HDL-C | ≥ 60 mg/dL | < 40 mg/dL | not applicable | |
| LDL-C | ≤ 100 mg/dL* | 130–159 mg/dL* | >160 mg/dL | |
| total cholesterol | < 200 mg/dL | 200–239 mg/dL | ≥ 240 mg/dL | |
| *For people with no other cardiovascular risk factors, LDL-C levels of 100–129 mg/dL is optimal. For people with other cardiovascular risk factors, LDL-C levels of 100–129 mg/dL is nearly optimal/slight risk. | ||||
The LIVER produces most of the cholesterol in the blood circulation, manufacturing this necessary chemical from saturated fats and other dietary NUTRIENTS. Dietary cholesterol is a minor factor in this process. The liver continues to manufacture cholesterol as long as it receives the ingredients, via ingested nutrients, to do so. Cells throughout the body also can synthesize cholesterol to meet their needs. The body stores some excess cholesterol, along with other fatty acids (notably triglycerides), in adipose tissue throughout the body. The body can then withdraw this cholesterol when liver synthesis slows. However, adipose tissue can hold only so much. Remaining excess cholesterol stays in the bloodstream.
Cholesterol Blood Levels - Low-Density Lipoprotein - LDL
The liver manufactures the lipoproteins that carry cholesterol as well as triglycerides and phospholipids (collectively called fatty acids or lipids). Different lipoproteins transport the kinds of fatty acids. Very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) transport some cholesterol and most of the triglycerides. It is the excesses of LDL cholesterol (LDL-C) and VLDL cholesterol (VLDL-C) that create increased cardiovascular health risks. These lipoprotein packages settle out of the blood easily, collecting against the inner walls of the arteries. Over time (typically decades) the lipoproteins, along with other cellular debris that gathers, infiltrates the innermost layer of the arterial wall and forms atherosclerotic plaque. This process is the foundation of ATHEROSCLEROSIS.
Cholesterol Blood Levels - High-density lipoprotein HDL
High-density lipoprotein (HDL) transports primarily cholesterol. It appears that HDL not only carries cholesterol from the liver but also picks up fragments of cholesterol-bearing LDL and VLDL and returns them to the liver, which disassembles them. Lowering the available lipoproteins in the body reduces the excess circulating in the bloodstream and increases the proportion of HDL cholesterol (HDL-C) to LDL-C/VLDL-C. Cells draw the cholesterol they need from the supply in circulation, helping maintain a healthy balance. Generally, the higher a person’s total cholesterol, the higher his or her LDL-C levels.
| ADDITIONAL CARDIOVASCULAR RISK FACTORS | ||
|---|---|---|
| age 65 or older | CONGENITAL HEART DISEASE | |
| DIABETES | family history of CARDIOVASCULAR DISEASE (CVD) | |
| female past MENOPAUSE | HEART ATTACK | |
| HYPERTENSION | ISCHEMIC HEART DISEASE (IHD) | |
| male, any age | OBESITY | |
| PERIPHERAL VASCULAR DISEASE (PVD) | physically inactive | |
| smoking | STROKE | |
| TRANSIENT ISCHEMIC ATTACK | ||
When the body’s nutrient intake is in balance, the liver uses up the nutrient components available to manufacture cholesterol and lipoproteins, sending into circulation the levels that the body can use. “Optimal” blood cholesterol values identify this balance, or lipid homeostasis, in which there is no increased cardiovascular risk in most people. Researchers have recently determined the LDL level to be the most significant in people who have other RISK FACTORS FOR CARDIOVASCULAR DISEASE.
| CHOLESTEROL-LOWERING MEDICATION RECOMMENDATIONS | |||
|---|---|---|---|
| LDL-C Level | Risk Factor Profile | Target LDL-C Level | |
| < 100 mg/dL | CVD + 2 or more CVD risk factors | 100 mg/dL | |
| 130–160 mg/dL | CVD | 100 mg/dL | |
| 160–190 mg/dL | 2 or more CVD risk factors | 130 mg/dL | |
| > 190 mg/dL | no CVD or risk factors | 160 mg/dL | |
| 190–219 mg/dL | male under age 35 | 160 mg/dL | |
| 190–219 mg/dL | female premenopause | 160 mg/dL | |
Current lipid-lowering treatment recommendations emphasize LDL-C blood values; the recommended LDL-C level depends on risk factors for CARDIOVASCULAR DISEASE (CVD). The higher the cardiovascular risk, the lower the recommended LDL-C level.
- Treatment may use lifestyle (diet and exercise) modification alone, which is effective for meeting LDL-C target levels for many people whose LDL-C blood values are 100–130 milligrams per deciliter (mg/dL) and who have no more than one additional CVD risk factor.
- For people who already have some form of CVD or who have two or more additional risk factors for CVD, treatment combines lifestyle with lipid-lowering medications.
- People who have very high CVD risk and very high LDL-C values may take two or more medications to bring their LDL-C blood levels to a healthier range.
Some cardiologists advocate driving LDL-C levels even lower, to 70 mg/dL, in people who have severe risk for HEART ATTACK or STROKE, such as those who have already had such a cardiovascular crisis and have numerous risk factors for cardiovascular disease. For most people, reaching the LDL-C target means a decrease of 30 to 40 percent.
See also CARDIOVASCULAR DISEASE PREVENTION; CHOLESTEROL, DIETARY; CHOLESTEROL, ENDOGENOUS; GARLIC; HYPERLIPIDEMIA; LIFESTYLE AND CARDIOVASCULAR HEALTH; MEDICATIONS TO TREAT CARDIOVASCULAR DISEASE; TRIGLYCERIDE BLOOD LEVEL; TRIGLYCERIDES, DIETARY.
