Lipid function test is done on a fasting blood sample for identifying various lipid abnormalities and it includes the estimation of total cholesterol, Triglycerides, HDL-cholesterol, LDL-cholesterol.
The major lipids present in the blood are cholesterol and triglycerides, which are transported in blood after incorporation into lipoproteins like chylomicrons, very low-density-lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL).
Disorders of lipoprotein metabolism (Dyslipidemia) include primary and secondary conditions that increase circulating lipids.
HDL is considered as good cholesterol as it carries cholesterol to the liver from where it can be removed from the bloodstream before it builds up in the arteries. LDL on the other hand takes the cholesterol directly to the arteries which can cause plaque buildup and atherosclerosis which can eventually lead to heart attacks. Hence, LDL is termed as bad cholesterol.
Hypercholesterolemia (increased total cholesterol in blood), is a cause of cardiac diseases that is highly treatable and, therefore, persons should be actively screened. It is recommended by the National Cholesterol Education Program that a fasting lipid profile should be carried out every 5 years beginning at the age of 20 years.
Preparation needed for Lipid Profile Test:
- Sample for lipid analysis requires 12-hour fasting.
- Triglycerides and LDL are affected by recent ingestion of food. Patients should be on a routine diet for 2-3 weeks before analysis.
- Lipid analysis should not be performed during acute illness and should be postponed for 3 months after a major illness.
- Drugs affecting lipid levels like steroids, oral contraceptives should be avoided.
Possible underlying causes for Lipid profile abnormalities:
- Patients with high serum triglycerides>200 mg/dl have the risk of atherosclerosis, and those with >1000 mg/dl are at increased risk of acute pancreatitis.
- An increase in triglyceride is associated with low HDL. Low HDL-cholesterol is a risk factor for coronary diseases even if the total cholesterol level is normal.
- High LDL-cholesterol is a strong risk factor for atherosclerotic heart disease and is associated with obesity, high carbohydrate food intake, diabetes mellitus, lack of exercise, smoking.
- Secondary lipoprotein diseases arise from underlying causes like diabetes mellitus, alcohol abuse, hypothyroidism.
Management of Dyslipidemia:
- For patients who are overweight, weight loss can help to reduce triglyceride levels.
- Obesity or overweight care involves three essential elements of lifestyle: dietary habits, physical activity, and behavior modification.
- Lifestyle changes are the first thing to tackle to reduce your chance of heart disease.
- Patients should receive dietary counseling to reduce the content of saturated fats, artificial trans fats, and cholesterol in the diet.
- The primary focus of diet therapy is to reduce overall calorie consumption. This reduction is consistent with a goal of losing 0.5-1kg/week. Examples include:
- Choose smaller and frequent meals at regular intervals.
- Eat more fruits and vegetables.
- Increase intake of dietary fiber.
- Consume more whole-grain cereals, beans, peas.
- Select leaner cuts of meat and skimmed dairy & dairy products.
- Reduce consumption of fried foods and foods with added fats and oils.
- Drink water instead of sugar-sweetened beverages, reduce sugar and sweets.
- Decrease sodium intake.
- Reduce saturated fat intake which you find in animal products.
- Foods with low-energy-density include soups, fruits, vegetables, oatmeal, and lean meats should be preferred.
- Foods with high-energy-density such as dry foods and high-fat foods such as cheese, egg yolks, potato chips, and red meat have a high-energy-density and should be avoided.
- The purpose of a Very Low-Calorie Diet (VLCD) is to have rapid and significant short-term weight loss over a 3 to 6 month period.
- A combination of dietary modification and exercise is the most effective behavioral approach for the treatment of obesity.
- Adults should engage in 150 min of moderate-intensity or 75 min of vigorous-intensity aerobic physical activity throughout the week.
- Regular aerobic exercise can lower bad cholesterol (LDL) and raise good cholesterol (HDL). Maintain adequate weight for your height.
- Have foods with unsaturated fats like nuts, fish, vegetable oil, olive oil, canola, and sunflower oils.
- Patients who drink alcohol should be encouraged to decrease or preferably eliminate their intake.
-Dr. Pendurthy Anoosha
- Jameson, Fauci, Kasper, Hauser, Longo, Loscalzo: Harrison’s principle of internal medicine, 20th ed, Ch 400, pg 2889-2902.
- Shirish M. Kawthalkar: Essentials of clinical pathology, 7th ed, ch 5, pg 69-74.