dyslpidemia

Question 1

What is cholesterol?

Answer 1

Cholesterol is a steroid that is synthesized by all animal cells, especially the liver. It is an integral part of cell membranes.

Question 2

What are triglycerides?

Answer 2

Triglycerides are a form of fat found within the blood. They consist of glycerol and three fatty acids.

Question 3

What are lipoproteins?

Answer 3

Lipoproteins are molecules that carry fats in the blood. They are composed of varying quantities of cholesterol, triglycerides, and apolipoproteins.

Question 4

What makes up the core of lipoproteins?

Answer 4

The core of lipoproteins consists of cholesterol esters and triglycerides.

Question 5

What makes up the surface of lipoproteins?

Answer 5

The surface of lipoproteins contains free cholesterol, apolipoproteins, and phospholipids.

Question 6

What is the role of HDL (high-density lipoproteins)?

Answer 6

HDL, also known as “good cholesterol,” delivers cholesterol from the tissues to the liver.

Question 7

What is the role of LDL (low-density lipoproteins)?

Answer 7

LDL, also known as “bad cholesterol,” delivers cholesterol from the liver to the tissues.

Question 8

What are the functions of VLDL (very low-density lipoproteins)?

Answer 8

VLDL delivers triglycerides from the liver to the tissues.

Question 9

What is the function of chylomicrons?

Answer 9

Chylomicrons transport triglycerides and cholesterol from the intestines into the liver.

Question 10

What is the basic cholesterol pathway in the liver?

Answer 10

The basic cholesterol pathway in the liver involves the conversion of acetyl CoA to HMG CoA, followed by the action of HMG-CoA reductase, leading to the synthesis of mevalonate, cholesterol, and bile acids. Bile acids are then recycled in the gut.

Question 11

What is the exogenous pathway of cholesterol transport?

Answer 11

In the exogenous pathway, dietary fats are transported from the gut in chylomicrons. The triglyceride component of chylomicrons is broken down by lipoprotein lipase in the endothelium, and the remnants are transported to the liver. The liver secretes bile acids and some cholesterol into the gut.

Question 12

What are the key steps in the endogenous pathway of cholesterol transport?

Answer 12

In the endogenous pathway, the liver produces VLDL, which is then broken down by lipoprotein lipase in the endothelium. The resulting intermediate density lipoproteins (IDL) are transported to the liver and converted to LDL. LDL binds to LDL receptors on peripheral tissues.

Question 13

What is the reverse pathway of cholesterol transport?

Answer 13

In the reverse pathway, some free cholesterol in tissues is taken up into HDL, and HDL is then transported to the liver.

Question 14

What is an ideal lipid profile?

Answer 14

An ideal lipid profile consists of low total cholesterol, low LDL cholesterol, high HDL cholesterol, and a low total/HDL ratio. Triglyceride levels should also be low.

Question 15

What is arcus senilis (corneal arcus)?

Answer 15

Arcus senilis is a white or grayish opaque ring or arc that forms around the cornea of the eye. It is associated with lipid disorders.

Question 16

What are xanthelasmata?

Answer 16

Xanthelasmata are lipid deposits in the skin, particularly around the eyes. They are often composed of lipid-laden macrophages.

Question 17

What are tendon xanthomas?

Answer 17

Tendon xanthomas are lipid deposits attached to the extensor surface tendons, such as the Achilles tendon. They are commonly seen in certain lipid disorders.

Question 18

What are palmar xanthomas?

Answer 18

Palmar xanthomas are lipid deposits in the skin creases of the hands. They are specific to familial dysbetalipoproteinemia, a type of lipid disorder.

Question 19

What are eruptive xanthomas?

Answer 19

Eruptive xanthomas are reddish bumps that appear suddenly. They are typically seen in severe hypertriglyceridemia and can appear on the elbows, forearms, trunk, legs, or buttocks.

Question 20

What is dyslipidemia?

Answer 20

Dyslipidemia refers to abnormal levels of lipids (cholesterol and triglycerides) in the blood. It is often characterized by elevated LDL cholesterol, decreased HDL cholesterol, or elevated triglycerides.

Question 21

What causes dyslipidemia?

Answer 21

Dyslipidemia can be caused by various factors, including diabetes mellitus, hypothyroidism, chronic kidney disease, chronic liver disease, obesity, smoking, certain medications (such as thiazide diuretics), and excessive alcohol consumption.

Question 22

What is severe hypertriglyceridemia?

Answer 22

Severe hypertriglyceridemia is a condition characterized by extremely high levels of triglycerides in the blood. It is often defined as triglyceride levels exceeding 500 mg/dL (5.6 mmol/L). It is associated with an increased risk of acute pancreatitis.

Question 23

What are the causes of primary dyslipidemia?

Answer 23

Primary dyslipidemia is caused by underlying genetic factors that lead to abnormal lipoprotein structure or abnormal lipoprotein receptors. These genetic abnormalities can result in elevated cholesterol or triglyceride levels.

Question 24

What is familial hypercholesterolemia?

Answer 24

Familial hypercholesterolemia is an inherited genetic disorder characterized by high LDL cholesterol levels from birth. It is caused by mutations in genes involved in LDL receptor function or clearance. Familial hypercholesterolemia significantly increases the risk of premature cardiovascular disease.

Question 25

What is Type I Familial hyperchylomicronemia?

Answer 25

In Type I Familial hyperchylomicronemia, the elevated lipoproteins are chylomicrons. It is caused by low lipoprotein lipase activity. Cholesterol levels are normal or high, and triglyceride levels are very high.

Question 26

What is Type IIa Familial hypercholesterolemia?

Answer 26

Type IIa Familial hypercholesterolemia is characterized by elevated LDL cholesterol levels. It is caused by low LDL receptor activity. Cholesterol levels are very high, while triglyceride levels are normal or high.

Question 27

What is Type IIb Familial combined hyperlipidemia?

Answer 27

Type IIb Familial combined hyperlipidemia is characterized by elevated levels of both LDL and VLDL. It is associated with high levels of APO B 100. Cholesterol levels are high, and triglyceride levels are high.

Question 28

What is Type III Familial dysbetalipoproteinemia?

Answer 28

In Type III Familial dysbetalipoproteinemia, the elevated lipoproteins are IDL and chylomicrons. It is caused by an Apo E mutation. Cholesterol levels are high, and triglyceride levels are very high

Question 29

What is Type IV Familial hypertriglyceridemia?

Answer 29

Type IV Familial hypertriglyceridemia is characterized by elevated VLDL levels. The primary cause is unknown. Cholesterol levels are normal or high, and triglyceride levels are high.

Question 30

What is Familial Hyperlipidemia Type I?

Answer 30

Familial Hyperlipidemia Type I, also known as hyperchylomicronemia, is a very uncommon condition characterized by a deficiency of lipoprotein lipase (autosomal recessive). It results in very high triglyceride levels and normal cholesterol levels. Spun blood appears creamy, and individuals are at risk of pancreatitis rather than ischemic heart disease.

Question 31

What is Familial Hypercholesterolemia Type IIa?

Answer 31

Familial Hypercholesterolemia Type IIa is an autosomal dominant condition characterized by very high LDL cholesterol levels, even at birth. Diagnosis should be considered if total cholesterol levels exceed 7.5 mmol/L. Triglyceride levels are typically near normal. The condition is caused by specific mutations that lead to the absence or very low levels of LDL receptors. It significantly increases the risk of severe atherosclerosis and ischemic heart disease, particularly in young adults, especially men.

Question 32

What is Familial Combined Hyperlipidemia Type IIb?

Answer 32

Familial Combined Hyperlipidemia Type IIb is an autosomal dominant condition characterized by moderately high levels of both cholesterol and triglycerides. It is commonly associated with insulin resistance and obesity. Multiple genetic defects, often polygenic, contribute to the condition, with overproduction of apolipoprotein B-100 being a common factor. This type of familial hyperlipidemia accounts for up to 20% of cases of premature ischemic heart disease.

Question 33

What is Familial Hypertriglyceridemia Type IV?

Answer 33

Familial Hypertriglyceridemia Type IV is characterized by elevated triglyceride levels (>5.0 mmol/L) and relatively normal cholesterol levels, often accompanied by low HDL cholesterol. It is associated with insulin resistance and obesity. There is an increased risk of acute pancreatitis if triglyceride levels exceed 10 mmol/L. The condition is not strongly associated with ischemic heart disease, and multiple genetic defects contribute to its development.

Question 34

What is Familial Hyperlipidemia Type III?

Answer 34

Familial Hyperlipidemia Type III, also known as familial dysbetalipoproteinemia, is caused by a deficiency of Apolipoprotein E (autosomal recessive). It leads to poor lipoprotein clearance by the liver, resulting in the persistence of chylomicrons and IDL in the blood. Modest elevations of cholesterol and triglycerides are observed, and individuals with this type of familial hyperlipidemia are at an increased risk of ischemic heart disease. Palmar xanthomas may be present.

Question 35

What are statins?

Answer 35

Statins are the first-line treatment for most patients with elevated cholesterol. Commonly prescribed statins include atorvastatin and simvastatin. They inhibit HMG-CoA reductase, an enzyme involved in cholesterol production by the liver. Statins lower LDL cholesterol, total cholesterol, and triglycerides while increasing HDL cholesterol. They have been proven in multiple clinical trials to reduce the risk of cardiovascular events, such as heart attacks and strokes. However, they may have side effects such as muscle pains (myalgia), rhabdomyolysis (a rare but dangerous muscle breakdown), joint pains (arthralgia), and liver dysfunction.

Question 36

What is ezetimibe?

Answer 36

Ezetimibe is a medication that works by reducing the absorption of cholesterol from the intestine. It is often used in combination with statins to further lower LDL cholesterol levels. Common side effects of ezetimibe include gastrointestinal symptoms such as diarrhea.

Question 37

What are resins?

Answer 37

Resins, also known as bile acid sequestrants, are medications that work by binding to bile acids in the intestine, preventing their reabsorption. This leads to increased bile acid synthesis and a subsequent reduction in LDL cholesterol levels. Resins, such as cholestyramine and colesevelam, can be effective in lowering LDL cholesterol. However, they may cause gastrointestinal side effects such as constipation and bloating.

Question 38

What are fibrates?

Answer 38

Fibrates, such as fenofibrate and gemfibrozil, are medications that primarily target triglyceride levels. They work by activating a specific receptor (PPAR-alpha) involved in lipid metabolism, leading to a decrease in triglycerides and an increase in HDL cholesterol. Fibrates may also have a modest effect on lowering LDL cholesterol. Common side effects include gastrointestinal symptoms, myopathy, and liver dysfunction.

Question 39

What is omega-3 fish oil?

Answer 39

Omega-3 fish oil supplements, which contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can help lower triglyceride levels. They are commonly used in patients with severe hypertriglyceridemia. Side effects are generally mild and may include gastrointestinal symptoms such as fishy aftertaste or burping.

Question 40

What are PCSK-9 inhibitors?

Answer 40

PCSK-9 inhibitors, such as evolocumab and alirocumab, are a newer class of medications that work by blocking the PCSK-9 enzyme. This enzyme reduces the number of LDL receptors, which are responsible for clearing LDL cholesterol from the bloodstream. By blocking PCSK-9, these medications increase the number of LDL receptors, leading to a significant reduction in LDL cholesterol levels. Common side effects include injection site reactions and flu-like symptoms.

Question 41

What is the Framingham Risk Score?

Answer 41

The Framingham Risk Score is a tool used to estimate the 10-year risk of cardiovascular events (such as heart attacks and strokes) based on various factors such as age, gender, cholesterol levels, blood pressure, smoking status, and diabetes. It is derived from the Framingham Heart Study, which has been monitoring the residents of Framingham, Massachusetts since 1948. The score helps in assessing the overall cardiovascular risk of an individual

Question 42

What are the NICE guidelines for statins in primary prevention?

Answer 42

According to the National Institute for Health and Care Excellence (NICE), statins are recommended for primary prevention if the 10-year risk of cardiovascular disease is greater than 10%. The Q-Risk score is often used to assess this risk. Lipid levels should be checked at 3 months, and the aim is to achieve an LDL reduction of more than 40%.

Question 43

When are fibrates typically used?

Answer 43

Fibrates, such as bezafibrate, are often used as the first-line treatment for patients with very high triglyceride levels. They work by activating lipoprotein lipase in the endothelium, leading to a reduction in triglycerides and LDL cholesterol, as well as an increase in HDL cholesterol. Side effects of fibrates include myalgia/rhabdomyolysis (muscle-related symptoms) and gastrointestinal disturbances.

Question 44

How do bile salt sequestrants work to reduce GI absorption?

Answer 44

Bile salt sequestrants, such as cholestyramine, work by preventing the reuptake of bile salts in the gut. This reduces fat absorption and diverts cholesterol toward bile salt production in the liver. While they have a mild effect in reducing LDL cholesterol, they can increase triglyceride levels. Side effects include gastrointestinal disturbances.

Question 45

What is the mechanism of action of ezetimibe?

Answer 45

Ezetimibe selectively inhibits the absorption of cholesterol by the small intestine. It does not affect the absorption of fat-soluble vitamins. Ezetimibe primarily lowers LDL cholesterol levels and is commonly used as an add-on therapy to statins. Side effects may include gastrointestinal disturbances.

Question 46

What is niacin (nicotinic acid)?

Answer 46

Niacin, also known as vitamin B3, inhibits lipase enzymes in adipose tissue. It mildly reduces LDL cholesterol and triglyceride levels while significantly increasing HDL cholesterol levels. It is used in patients with very high levels of lipoprotein(a). Niacin’s side effect includes facial flushing.

Question 47

What is the mechanism of PCSK9 inhibition?

Answer 47

PCSK9 is a circulating enzyme that binds to the LDL receptor and reduces LDL clearance. PCSK9 inhibitors block this action, leading to a reduction in LDL cholesterol levels. They also reduce triglycerides and increase HDL cholesterol. These medications are very powerful but expensive, typically used for conditions such as familial hypercholesterolemia or in patients who fail to reach target goals on statins alone. Side effects may include cough, flu-like symptoms (associated with monoclonal antibodies).

Question 48

Why is cardiovascular prevention important?

Answer 48

Cardiovascular prevention is crucial because it aims to reduce the risk of cardiovascular events such as heart attacks and strokes. By identifying individuals at high risk, appropriate interventions can be implemented to manage risk factors and prevent the progression of cardiovascular disease.

Question 49

What management strategies are recommended for hyperlipidemia?

Answer 49

Management strategies for hyperlipidemia include incorporating aerobic exercise, smoking cessation, alcohol moderation, weight loss for obese patients, and dietary modifications. Dietary recommendations often include portion control, limiting carbohydrates (especially refined sugars), and incorporating oily fish that are high in omega-3 fatty acids.