Disorders of Lipid Metabolism: Cholesterol

Cholesterol is transported to and from the cells by carriers called lipoproteins. Low-density lipoprotein, or LDL, is known as “bad” cholesterol. High-density lipoprotein, or HDL, is known as “good” cholesterol. These two types of lipids, along with triglycerides and Lp(a) cholesterol, make up your total cholesterol count, which can be determined through a blood test.

LDL (Bad) Cholesterol

When too much LDL (bad) cholesterol circulates in the blood, it can slowly build up in the inner walls of the arteries that feed the heart and brain. Together with other substances, it can form plaque, a thick, hard deposit that can narrow the arteries and make them less flexible. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, heart attack or stroke can result.

LDL Cholesterol Levels

Less than 100 mg/dL Optimal
100 to 129 mg/dL Near Optimal/ Above Optimal
130 to 159 mg/dL Borderline High
160 to 189 mg/dL High
190 mg/dL and above Very High

HDL (good) Cholesterol

About one-fourth to one-third of blood cholesterol is carried by high-density lipoprotein (HDL). HDL cholesterol is known as “good” cholesterol, because high levels of HDL seem to protect against heart attack. Low levels of HDL (less than 40 mg/dL) also increase the risk of heart disease. Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe that that HDL removes excess cholesterol from arterial plaque, thus slowing its buildup.

Triglycerides

Triglyceride is a form of fat made in the body. Elevated triglycerides can be due to overweight/obesity, physical inactivity, cigarette smoking, excess alcohol consumption and a diet very high in carbohydrates (60 percent of total calories or more). People with high triglycerides often have a high total cholesterol level, including a high LDL (bad) level and a low HDL (good) level. Many people with heart disease and/or diabetes also have high triglyceride levels.

Normal: less than 150 mg/dL
Borderline-High: 150–199 mg/dL
High: 200–499 mg/dL
Very High: 500 mg/dL

Lp(a) Cholesterol

Lp(a) is a genetic variation of LDL (bad) cholesterol. A high level of Lp(a) is a significant risk factor for the premature development of fatty deposits in arteries. Lp(a) isn’t fully understood, but it may interact with substances found in artery walls and contribute to the buildup of fatty deposits.

Do you know your numbers?

I just had a blood test and my HDL was below 50. Tomorrow I will post on how I plan on increasing my HDL.


For Canadians:

Target LDL, HDL and total cholesterol:HDL levels

An LDL cholesterol level of less than 3.0 mmol/L is best
An HDL above 1.0 mmol/L is best
If your risk is low, your LDL cholesterol should be less than 5.0 mmol/L and total cholesterol HDL-C ratio should be less than 6.0
If your risk is moderate, your LDL cholesterol should be less than 3.5 mmol/ and total cholesterol HDL-C ratio should be less than 5
If your risk is high, your LDL cholesterol should be less than 2.0 mmol/L and total cholesterol HDL-C ratio should be less than 4.0
An HDL cholesterol level of less than 1.0 mmol/L means you're at higher risk for heart disease.
If you have diabetes, your LDL should be less than 2.0 mmol/L.
If you've already had a heart attack your LDL needs to be less than 2.0 mmol/L.