Lipid function testing is performed on a fasting blood sample to detect various lipid abnormalities and includes evaluation of total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol.
The main lipids present in the blood are: cholesterol and: triglycerideswhich are transported in the blood into lipoproteins such as chylomicrons, very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) after incorporation.
Disorders of lipoprotein metabolism (dyslipidemia) include primary and secondary conditions that increase circulating lipids.
HDL is considered good cholesterol because it transports cholesterol to the liver, where it can be removed from the bloodstream before it builds up in the arteries. On the other hand, LDL transports cholesterol directly into the arteries, which can cause plaque build-up and atherosclerosis, which can eventually lead to heart attacks. Therefore, LDL is called bad cholesterol.
Hypercholesterolemia (increased total cholesterol in the blood), is a cause of heart disease that is highly treatable, and therefore people should be actively screened. The National Cholesterol Education Program recommends that a fasting lipid profile be performed every 5 years beginning at age 20.
Necessary preparation for the lipid profile test:
- For lipid analysis, the sample requires a 12-hour fast.
- Triglycerides and LDL are affected by recent food intake. Before the analysis, patients should go on a normal diet for 2-3 weeks.
- Lipid analysis should not be performed during acute illness and should be delayed for 3 months after severe illness.
- Medications that affect lipid levels, such as steroids, oral contraceptives, should be avoided.
Possible underlying causes of lipid profile abnormalities:
- Patients with high serum triglycerides > 200 mg/dL are at risk of atherosclerosis, and those above 1000 mg/dL are at risk of acute pancreatitis.
- Increased triglyceride is associated with lower HDL. Low HDL-cholesterol is a risk factor for coronary disease, 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, lack of physical exercise, and smoking.
- Secondary lipoprotein diseases are caused by underlying causes such as diabetes, alcohol abuse, hypothyroidism.
Management of dyslipidemia.
- For overweight patients, weight loss can help lower triglyceride levels.
- Obesity or overweight care involves three key lifestyle elements: diet, physical activity, and behavior change.
- Lifestyle changes are the first thing to address to reduce the risk of heart disease.
- Patients should receive dietary counseling to reduce saturated fat, artificial trans fat, and cholesterol in the diet.
- The main goal of diet therapy is to reduce total calorie consumption. This reduction corresponds to a weight loss goal of 0.5-1 kg/week. Examples include:
- Choose smaller and more frequent meals at regular intervals.
- Eat more fruits and vegetables.
- Increase your dietary fiber intake.
- Use more whole grains, beans, peas.
- Choose leaner cuts of meat and low-fat dairy and dairy products.
- Reduce your intake of fried foods and foods with added fats and oils.
- Drink water instead of sugary drinks, reduce sugar and sweets.
- Reduce sodium intake.
- Reduce your intake of saturated fat, which you find in animal products.
- Foods with low energy density include soups, fruits, vegetables, oatmeal, and lean meats should be preferred.
- Foods with a high energy density such as dry and fatty foods such as cheese, egg yolks, potato chips and red meat have a high energy density and should be avoided.
- The goal of a very low calorie diet (VLCD) is to achieve rapid and significant short-term weight loss within 3 to 6 months.
- A combination of dietary modification and exercise is the most effective behavioral approach to treating obesity.
- Adults should do 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic exercise per week.
- Regular aerobic exercise can lower bad cholesterol (LDL) and raise good cholesterol (HDL). Maintain an appropriate weight for your height.
- Eat foods high in unsaturated fats, such as nuts, fish, vegetable oil, olive oil, canola, and sunflower oils.
- Patients who consume alcohol should be encouraged to reduce or preferably eliminate their intake.
If diet and exercise do not lower cholesterol levels, medication or combinations of treatments are prescribed by your doctor after ruling out secondary causes.
-Dr. Pendurthi Anusha
Links:
- Jameson, Fauci, Kasper, Hauser, Longo, Loscalzo. Harrison’s principles of internal medicine, 20th ed, Ch 400, pp. 2889-2902.
- Shirish M. Kavtalkar: Basic Principles of Clinical Pathology, 7th Edition, Chap. 5, pp. 69-74.