When we take into consideration heart health, we regularly take into consideration food plan and the way we are able to lower cholesterol. For our patients, assessing their lipid profile helps determine their risk of heart problems. The lipid profile also helps discover patients in danger for familial hypercholesterolemia, discover potential causes of pancreatitis, treat patients with atherosclerotic heart problems (ASCVD), and assess the effectiveness or adherence to lipid-lowering therapy and lifestyle modifications (Sandeep, 2024). Let’s take a better take a look at the lipid components in our blood.

There are five major lipoproteins in our blood: chylomicrons, very low density lipoproteins (VLDL); intermediate density lipoproteins (IDL); low density lipoproteins (LDL), and high density lipoproteins (HDL) (Vijan, 2024). Each of those carries various amounts of cholesterol and triglycerides. LDL carries the vast majority of cholesterol, while VLDL acts as the first carrier of triglycerides. A typical blood lipid profile measures total cholesterol, HDL cholesterol, and triglycerides. LDL cholesterol is then estimated from these values.

The goal range for levels of cholesterol is (Centers for Disease Control and Prevention [CDC]2020):

Fasting and non-fasting study

Fasting (8 to 12 hours without food) isn’t often required for lipid testing, apart from initial lipid measurements and patients being observed for known hypertriglyceridemia. A fasting lipid profile may additionally be needed in the next cases:

• If your cholesterol screening test result is larger than 250 mg/dl
• If your HDL cholesterol screening test result’s lower than 40 mg/dl
• Family history of genetic hyperlipidemia
• Evaluating Patients for Hypertriglyceridemia
• Overweight patients
• Diabetes patients
• Patients who devour significant amounts of alcohol
• Patients taking medications resembling steroids that increase triglyceride levels

If plasma triglyceride concentration (postprandial) exceeds 400 mg/dl, a fasting lipid profile test must be performed.

Lipid profile components (Rosenson, 2022)

LDL-C

or “bad” cholesterol, in high concentrations can accumulate in arteries and increase the chance of heart attack, stroke and peripheral artery disease (American Heart Association) [AHA]2017). LDL-C is a key lipid marker for assessing cardiovascular risk and helping to guide treatment strategies. In patients undergoing lipid-lowering modifications, LDL-C must be monitored every six weeks after starting therapy until the goal LDL-C level is achieved. Thereafter, measurements could be checked every 6 to 12 months.

LDL-C is commonly calculated using the Friedewald equation, the Martin/Hopkins method, the Sampson/NIH method, or by direct measurement if the whole triglyceride level is larger than 400 mg/dL.

: LDL cholesterol = Total cholesterol – VLDL cholesterol – HDL cholesterol

The Friedewald equation has several drawbacks. It is an estimate because VLDL can’t be measured directly. VLDL is calculated by dividing total triglycerides by 5. All values ​​have to be obtained from a fasting patient, and the formula can’t be used if the patient’s total triglyceride level is larger than 400 mg/dL.

This has been found to be more accurate than the Friedewald equation in patients with LDL-C levels below 70 mg/dL and triglyceride levels above 150 mg/dL (Ferraro et al., 2019). This equation uses adjustable coefficients based on the patient’s individual non-HDL-C and triglyceride values. Another advantage of this equation is that it doesn’t require the patient to fast before the test.

It could be utilized in patients with plasma triglyceride levels as much as 800 mg/dl. The most accurate measurement of LDL-C uses; nevertheless, the method is complex and expensive.

Studies conducted using LDL-C assays or chemical-based methods will not be reliable or standardized and should be less accurate than the Friedewald equation (Ferraro et al., 2019).

Non-HDL-C

The measurements provide one other strategy to estimate the chance of atherogenic lipoproteins, which are likely to form fatty plaques within the arteries. It is calculated by subtracting HDL-C from total cholesterol and includes all cholesterol present in lipoprotein particles which might be considered atherogenic, including LDL-C, lipoprotein(a), IDL, and VLDL. This value is helpful in individuals with low or normal LDL-C, low HDL-C, and elevated triglycerides (200 mg/dL or higher). Non-HDL-C can also be a sensitive screening test for dyslipidemia in children (de Ferranti & Newburger, 2020). However, this laboratory test isn’t routinely measured.

HDL-C

is taken into account “good” cholesterol since it transports LDL cholesterol from the arteries to the liver, where it’s broken down and faraway from the body (AHA, 2017). Only about one-third to one-quarter of total LDL is transported by HDL. Healthy levels of HDL cholesterol may help reduce the chance of heart attack and stroke, while low levels of HDL increase these risks (AHA, 2017), but a cause-and-effect relationship has not been established. HDL-C is measured directly, and blood samples could be taken either fasting or not.

Triglycerides

High levels combined with high LDL or low HDL may cause fat to accumulate within the arteries, increasing the chance of heart attack and stroke (AHA, 2017). Triglyceride levels help discover patients with other metabolic disorders resembling diabetes, fatty liver disease, or nonalcoholic fatty liver disease. Monitoring triglyceride levels will help doctors discover the explanation for acute pancreatitis, monitor treatment for hypertriglyceridemia, and screen relations for familial hypertriglyceridemia. Triglycerides must be measured with patients fasting, if possible.

Projection (Sandeep, 2024)

Children with a number of risk aspects for premature heart problems (CVD) should undergo selective screening (de Ferranti & Newburger, 2020). Children without CVD risk aspects must be screened for dyslipidemia twice: at ages 9 to 11 and again at ages 17 to 21 (de Ferranti & Newburger, 2020). Young adults who weren’t screened as children must have a lipid profile once they begin seeing their adult primary care physician to screen for familial hyperlipidemia and assess cardiovascular risk (Sandeep, 2024). If results are normal, the timing and frequency of future screening must be determined based on the patient’s cardiovascular risk and potential interventions that will improve outcomes. For lower-risk adults, Sandeep (2024) suggests that lipid screening begin at age 35 for men and 45 for ladies, after which every five years. More frequent screening is advisable for those with a family history of premature ASCVD or when multiple risk aspects are present (i.e., repeat screening every three years), starting at age 30–35 for men and 25–30 for ladies. Specific lipid-related clinical aspects that “increase risk” for adults at borderline or intermediate risk for ASCVD include:

• LDL-C greater than or equal to 160 mg/dl or non-HDL-C greater than or equal to 190 mg/l
• Fasting triglyceride level greater than or equal to 175 mg/dl
• Lp(a) greater than or equal to 50 mg/dl
• Apolipoprotein B greater than 130 mg/dl

American Heart Association (2017). HDL (good), LDL (bad) cholesterol, and triglycerides. https://www.heart.org/pl/tematy-zdrowia/cholesterol/hdl-dobry-ldl-zly-cholesterol-i-triglycerides

Centers for Disease Control and Prevention (2020). Check your cholesterol. https://www.cdc.gov/cholesterol/cholesterol_screening.htm

De Farranti, SD and Newburger, JW (2020). Dyslipidemia in children: Definition, screening, and diagnosis. https://www.uptodate.com/contents/dyslipidemia-in-children-definition-research-and-diagnostics

Ferraro, R. A., Sathiyakumar, V., & Blumenthal, R. S. (2019). Understanding the strengths and limitations of various methods for estimating LDL-C. American College of Cardiology. https://www.acc.org/latest-in-cardiology/articles/2019/04/02/13/21/understanding-strengths-and-limitations-of-different-methods-of-ldl-c-estimation

Rosenson, RS (2022, October 14). Measurement of lipids and lipoproteins in blood. https://www.uptodate.com/contents/measurement-of-lipids-and-lipoproteins-in-blood

Sandeep, V. (2024, March 4). Screening for lipid disorders in adults. https://www.uptodate.com/contents/badania-przesiewowe-w-kierunku-zaburzen-lipidowych-u-doroslych