- Lipidiologist – Specialist in Cholesterol & Triglycerides, Practicing in Rockville, Montgomery County, Maryland
- Physiology of Cholesterol
- Definition, Prevalence, and Consequences of High Cholesterol
- How Elevated Cholesterol Leads to Atherosclerosis and CVD
- Preventing or Reversing Atherosclerosis
- Key Lipid Particles Involved in Formation of Heart Disease
- Lipid Testing
- Lifestyle Improvements as the Central Approach to Reducing CVD Harm
- Essential Medical Treatments for Dyslipidemia
- Close Patient Monitoring is Paramount
Lipidiologist – Specialist in Cholesterol & Triglycerides, Practicing in Rockville, Montgomery County, Maryland
As a board-certified lipidologist by the American Board of Clinical Lipidology, practicing in Rockville, Montgomery County, Maryland, one of my roles in the community is to help patients optimize cholesterol levels and guide them towards making informed decisions to prevent or reverse the development of cardiovascular disease (CVD).
In this article, we explore the physiological role of cholesterol, the consequences of dyslipidemia, and the link between hypercholesterolemia and atherosclerosis. Next, we discuss the significance of preventing atherosclerosis, key lipid molecules involved in pathology, and the use of standard and advanced lipid testing. Lastly, we delve into lifestyle adjustments for improving lipids, commonly prescribed medications for dyslipidemia, and how to monitor patients over time.
Physiology of Cholesterol
Cholesterol, a waxy substance, plays a vital role in various physiological functions within the human body. It is an essential component of cell membranes, providing structural integrity and facilitating cellular communication. Cholesterol also serves as a precursor for the synthesis of bile acids, which aid in fat digestion, and steroid hormones, including cortisol, estrogen, and testosterone.
Definition, Prevalence, and Consequences of High Cholesterol
Dyslipidemia refers to an abnormal lipid profile characterized by elevated levels of cholesterol and triglycerides in the blood. It is a prevalent condition affecting millions worldwide. If left untreated, dyslipidemia can cause serious diseases that impact various bodily systems, such as the liver, gut, brain, balance, kidney, skin, and inflammation.
However, by far, the most common complication of high cholesterol is atherosclerosis. Atherosclerosis occurs when fatty deposits called plaques accumulate within arterial walls, restricting blood flow and increasing the risk of heart attacks and strokes.
How Elevated Cholesterol Leads to Atherosclerosis and CVD
Hypercholesterolemia, the condition characterized by high levels of cholesterol in the blood, is a major contributor to the initiation of atherosclerosis. Excess cholesterol, particularly low-density lipoprotein (LDL) cholesterol, accumulates within the arterial walls, triggering an inflammatory response.
This inflammatory process recruits immune cells and promotes the formation of plaques. Over time, these plaques can rupture, leading to the formation of blood clots that may block blood flow and result in life-threatening events such as heart attacks or strokes.
Preventing or Reversing Atherosclerosis
Preventing or reversing atherosclerosis is of paramount importance for achieving longevity and reducing the societal cost burden. By adopting lifestyle modifications such as a heart-healthy diet, regular exercise, weight management, and smoking cessation, individuals can lower their cholesterol levels, reduce plaque formation, and improve cardiovascular health. These preventive measures not only save lives but also help alleviate the economic strain caused by the treatment and complications of CVD.
Key Lipid Particles Involved in Formation of Heart Disease
1. Non-HDL cholesterol (non-HDL-C)
Non-HDL-C, which includes LDL cholesterol and other cholesterol-containing particles, is widely regarded as the most significant marker of cardiovascular risk. It is derived by subtracting HDL cholesterol from the total cholesterol. Non-HDL-C represents the combined existence of various “bad particles”, including LDL, VLDL, and IDL. Elevated levels of non-HDL cholesterol indicate an increased risk of plaque formation and a higher likelihood of developing CVD.
2. LDL cholesterol (LDL-C)
LDL-C is the primary lipid measurement used to assess cardiovascular harm due to historical and practical considerations. While it is the most detrimental cholesterol particle, LDL-C (unlike non-HDL-C) does not encompass the additional “bad cholesterol” found in VLDL and IDL particles. However, it is important to highlight that LDL-C remains highly useful in approximately 80% of individuals, with its practical value being comparable to that of non-HDL cholesterol.
Triglycerides, which are another type of lipid, also contribute to the development of atherosclerosis and are frequently elevated in individuals with diabetes, insulin resistance, and metabolic syndrome, further increasing their risk of cardiovascular complications
Common lipid testing, which measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels, should be performed after an overnight fast. Fasting ensures accurate measurement of triglyceride levels, as they can be influenced by recent food intake.
In certain situations, advanced lipid testing may be necessary to obtain a more comprehensive assessment of cardiovascular risk. Advanced tests include evaluating lipoprotein(a) [Lp(a)], apolipoprotein B (Apo B), apolipoprotein E (Apo E) in relation to triglycerides, nuclear magnetic resonance (NMR) particle size and number, and cardiac C-reactive protein (CRP) levels. These tests offer additional insights into an individual’s lipid profile and aid in risk stratification.
Lifestyle Improvements as the Central Approach to Reducing CVD Harm
Lifestyle changes form the cornerstone of lipid management and are crucial in achieving optimal lipid levels. Adopting a heart-healthy diet, rich in fruits, vegetables, whole grains, and lean proteins, while limiting saturated and trans fats, can significantly improve lipid profiles. Engaging in regular physical activity and maintaining a healthy weight also contribute to favorable changes in lipids and overall cardiovascular health.
Essential Medical Treatments for Dyslipidemia
While lifestyle modifications play a crucial role in lipid management, medications are often necessary to achieve optimal lipid levels. In this section, we will explore the key medications used to treat dyslipidemia and their respective classes.
Statins are the most commonly prescribed medications for dyslipidemia. They work by inhibiting an enzyme in the liver involved in cholesterol synthesis, thereby reducing the production of LDL cholesterol. Some well-known statins include atorvastatin and rosuvastatin. Statins have been shown to effectively lower LDL cholesterol levels and have demonstrated substantial cardiovascular benefits. They are typically the first-line treatment for individuals at risk of CVD.
Ezetimibe is another medication used to treat hypercholesterolemia. It works by blocking the absorption of cholesterol from the small intestine, leading to reduced LDL cholesterol levels. Ezetimibe is often prescribed in combination with statins when statin therapy alone is insufficient in achieving the desired lipid goals. This combination therapy has shown greater efficacy in lowering LDL cholesterol compared to statins alone.
Fenofibrate belongs to a class of medications called fibrates and is primarily used to target elevated triglyceride levels. Fenofibrate works by reducing the formation of triglycerides in the liver and increasing the breakdown of triglyceride-rich particles in the blood. It also helps increase levels of high-density lipoprotein (HDL) cholesterol, often referred to as “good cholesterol.” Fenofibrate is particularly beneficial for individuals with high triglyceride levels, frequently seen in patients with diabetes, insulin resistance, and metabolic syndrome.
4. PCSK9 Inhibitors
Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are a newer class of medications that effectively lower LDL cholesterol levels. They work by blocking the PCSK9 enzyme, which promotes the breakdown of LDL receptors in the liver. By inhibiting PCSK9, these medications allow more LDL receptors to be available, leading to increased clearance of LDL cholesterol from the bloodstream. PCSK9 inhibitors, such as evolocumab and alirocumab, are typically prescribed for individuals with genetic hypercholesterolemia or those who have experienced intolerance or inadequate response to other lipid-lowering therapies.
5. Bempedoic Acid
Bempedoic acid is a recently approved medication that lowers LDL cholesterol levels by inhibiting a key enzyme (ATP Citrate Lyase) involved in cholesterol synthesis. It is often prescribed in combination with ezetimibe or as an alternative for individuals who cannot tolerate statins. Bempedoic acid offers an additional treatment option for individuals with inherited hypercholesterolemia or those who require additional LDL cholesterol reduction.
Leqvio is a novel RNA-based therapy that targets the production of a PCSK9 protein involved in LDL cholesterol synthesis. It is administered twice yearly through subcutaneous injections and has shown significant LDL cholesterol-lowering effects. Leqvio is primarily prescribed for individuals with severe familial hypercholesterolemia (HoFH) or those with established CVD who require additional LDL cholesterol reduction.
In short, dyslipidemia is effectively managed through a combination of lifestyle adjustments and medication therapy. Statins remain the first-line treatment for dyslipidemia, while other medications such as ezetimibe, fenofibrate, PCSK9 inhibitors, bempedoic acid, and Leqvio provide additional options for achieving optimal lipid levels. The choice of medication depends on individual patient characteristics, lipid profile, cardiovascular risk, and any underlying conditions.
Close Patient Monitoring is Paramount
Monitoring patients over time is essential to assess the effectiveness of interventions and adjust treatment strategies accordingly. Non-HDL cholesterol and LDL cholesterol targets vary depending on an individual’s cardiovascular risk profile.
High-risk patients, such as those with diabetes or established CVD, generally require more aggressive treatment goals like LDL cholesterol concentration less than 55-70 mg/dL.
Regular follow-up appointments, along with repeated lipid testing, allow the cholesterol expert to evaluate progress, modify medication doses if necessary, and ensure patients are achieving their lipid targets.
As a lipidologist (a specialist in cholesterol and triglycerides), one of my aims is to guide patients in maintaining optimal cholesterol levels to prevent atherosclerosis.
Dyslipidemia and hypercholesterolemia significantly contribute to the development of cardiovascular disease, which remains the leading cause of death in the United States and worldwide.
By promoting lifestyle changes, implementing appropriate lipid testing, and utilizing effective medications, we can enhance cardiovascular health, save lives, and reduce the socioeconomic burden associated with CVD. Together, we can pave the way towards a healthier future for all.