lipid profile

Introduction

 

 

What is a lipid profile? 

 

The lipid profile is a group of tests that are often ordered together to determine risk of coronary heart disease. The tests that make up a lipid profile are tests that have been shown to be good indicators of whether someone is likely to have a heart attack or stroke caused by blockage of blood vessels (hardening of the arteries). 

 

 

What tests are included in a lipid profile? 

 

The lipid profile includes total cholesterol, HDL-cholesterol (often called good cholesterol), LDL-cholesterol (often called bad cholesterol), and triglycerides. Sometimes the report will include additional calculated values such as HDL / Cholesterol ratio or a risk score based on lipid profile results, age, sex, and other risk factors. 

 

 

How is a lipid profile used? 

 

The lipid profile is used to guide providers in deciding how a person at risk should be treated. The results of the lipid profile are considered along with other known risk factors of heart disease to develop a plan of treatment and follow-up. 

 

 

Lipid metabolism

 

Most of the dietary fat is absorbed into the blood in chylomicrons. Triglyceride is removed from the chylomicrons by lipoprotein lipase in the blood, fatty acids released are taken up by the adipose tissue (Fat storage tissue) and the chylomicron ramnants are removed by the liver. Triglyceride taken up by the liver is broken down to 2-carbon fragments which are used in many metabolic processes. Free fatty acids liberated by the adipose tissue is also taken up by the liver and used in similar way. 

In these processes lipid aggregates are formed containing triglycerides, phospholipids and cholesterol. These are combined with apoproteins to form Lipoproteins which are released into the blood.

These Lipoproteins are:

1. VLDL - Very Low Density Lipoproteins
2. IDL - Intermediate density Lipoproteins
3. LDL - Low Density Lipoproteins
4. HDL - High Density Lipoproteins

 

The density of the lipoproteins is determined by the relative protein and lipid content with high density lipoproteins containing high protein and fewer lipids.

The liver synthesizes more cholesterol than any other organ. The cholesterol is incorporated into lipoproteins or converted to bile acids or excreted into bile. In biliary obstruction of any kind serum lipid concentration increases mainly due to formation of abnormal lipoprotein known as Lipoprotein X

 

 

What is cholesterol?

 
Cholesterol is a substance both made by the body and consumed in food products that come from animals. Primarily, it travels in the blood as two compounds: low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Lower Cholesterol refers to LDL.
In practice, HDL is often called the 'good' cholesterol and LDL is called the 'bad' cholesterol. 

The reason for this is that HDLs help transport cholesterol in the body to the liver, where the body then prepares to excrete it. LDLs, on the other hand, actually transport cholesterol from the liver to cells in the body.
Once the body's cells have all of the cholesterol they need, the extra cholesterol can build up along blood vessel walls as plaque. People with high total cholesterol to HDL cholesterol ratios want to Lower Cholesterol, are at increased risk for heart disease because in general, they are transporting more cholesterol to cells than they need. 

 

Normal range of cholesterol in the blood should be less than 200 milligrams per deciliter or mg/dl. High cholesterol of 240 mg/dl or greater in the blood increases the risk of heart disease, stroke, coronary artery disease etc. Abnormally low levels of cholesterol may indicate hyperthyroidism, or an overactive thyroid gland, liver disease, inadequate absorption of nutrients from the intestines and malnutrition

Why Is It Important to Lower Cholesterol?

Lower Cholesterol is important to living a long and healthy life, one that is free from heart disease or stroke.
Those are risk factors that come with elevated levels of cholesterol. The health problems arise when there is too much total cholesterol and you want to Lower Cholesterol in the blood because it can no longer move freely through the arteries.
Over time excess cholesterol builds up against the artery walls and narrows the space through which blood flows. This narrowing of the arteries is called atherosclerosis

 

Care before the procedure

 
Avoid solid foods or drinks except water for 9 to 12 hours before taking the blood sample for Lipoprotein analysis (total cholesterol, LDL, HDL, and triglyceride levels). 

How the test is done

Lipoprotein analysis or Lipid profile is normally performed on a blood sample taken from a vein. This procedure takes only a few minutes. The blood sample is collected in a syringe or vial and sent to the lab to be analyzed. Total cholesterol levels may also be measured from a finger-stick blood sample.

Age for Testing 

Adults 20 years or over should be routinely tested every five years for cholesterol, LDL, HDL and triglycerides. Children of parents with high cholesterol over 240mg/dl should be checked regularly after age 7.

 

 LDL Cholesterol(mg/dl) 

=Total cholesterol-HDL Cholesterol -  Triglycerides/ 5