p.1
Frederickson Classification of Dyslipidemias
What limitation does the Frederickson classification have?
It is not a diagnostic classification and provides little clue about the etiology of the disorder.
p.7
Clinical Disorders of Lipoprotein Metabolism
What are the clinical manifestations of Tangier disease?
Hypertrophied yellow-orange tonsils, enlargement of the liver and spleen, and peripheral neuropathy.
p.3
Familial Hypercholesterolemia
What is the prevalence of familial lipoprotein lipase deficiency?
About 1 in 1,000,000 people.
What is fish-eye disease associated with?
Low HDL cholesterol concentrations and eye abnormalities.
p.3
Familial Hypercholesterolemia
What is the typical total cholesterol range in heterozygotes for familial hypercholesterolemia?
7.5-12 mmol/L (290 – 460 mg %).
p.2
Frederickson Classification of Dyslipidemias
What is a major advantage of the Fredrickson classification?
It is widely accepted and provides guidance for treatment.
p.6
Common Causes of Hyperlipidemias
What does low lipid levels indicate?
They may indicate the presence of another disorder or be a primary genetic disease.
p.4
Genetic Causes of Dyslipidemias
How is familial combined hyperlipidemia inherited?
As an autosomal dominant trait.
p.4
Diagnosis of Dyslipoproteinemias
What is a key diagnostic indicator for familial combined hyperlipidemia?
A family history of hyperlipidemia with different lipoprotein phenotypes.
What condition is associated with LCAT deficiency?
Corneal opacities, renal damage, premature atherosclerosis, and hemolytic anemia.
p.4
Clinical Disorders of Lipoprotein Metabolism
What biochemical markers are elevated in familial dysbeta-lipoproteinemia?
Excess of IDL and chylomicron remnants.
p.4
Common Causes of Hyperlipidemias
What factors can influence the expression of familial dysbetalipoproteinemia?
Obesity, alcohol, hypothyroidism, and diabetes.
p.3
Familial Hypercholesterolemia
What is a significant risk factor for heterozygotes of familial hypercholesterolemia?
They tend to develop coronary artery disease 20 years earlier than the general population.
p.8
Lipoprotein(a) Elevation
What is Lipoprotein(a) composed of?
An LDL particle containing apo B100 linked to another apoprotein, apo(a).
p.7
Common Causes of Hyperlipidemias
What lifestyle changes are advised to increase HDL cholesterol levels?
Losing weight, increasing physical activity, and stopping smoking.
p.4
Familial Hypercholesterolemia
What are the typical plasma triglyceride levels in familial combined hyperlipidemia (FCH)?
Between 2 mmol/L and 6 mmol/L (175 – 530 mg %).
p.4
Frederickson Classification of Dyslipidemias
Which Fredrickson’s phenotypes are associated with familial combined hyperlipidemia?
Phenotypes IIa, IIb, and IV.
p.5
Secondary Hyperlipidemias
What are some causes of secondary hyperlipidemia with predominant hypercholesterolemia?
Hypothyroidism, nephrotic syndrome, cholestasis, acute intermittent porphyria, anorexia nervosa/bulimia, certain drugs or toxins.
p.3
Clinical Disorders of Lipoprotein Metabolism
What role does lipoprotein lipase play in lipid metabolism?
It hydrolyzes chylomicrons to form chylomicron remnants and converts VLDL to IDL particles.
p.4
Common Causes of Hyperlipidemias
What typically causes raised plasma cholesterol concentrations in polygenic hypercholesterolemia?
Increased LDL production or decreased LDL catabolism.
p.2
Frederickson Classification of Dyslipidemias
What type of classification is used for primary hyperlipidemias nowadays?
A more descriptive classification.
Why is the study of hyperlipidemias important?
Due to the involvement of lipids in cardiovascular disease.
p.6
Common Causes of Hyperlipidemias
What is one cause of low lipid levels related to diet?
Malnutrition, which is a lack of food, including fats.
What does hyperalphalipoproteinemia result in?
Elevated plasma HDL cholesterol concentration.
p.6
Familial Hypercholesterolemia
What is a major consequence of abetalipoproteinemia?
Severe vitamin E deficiency.
p.8
Lipoprotein(a) Elevation
What effect does estrogen have on Lipoprotein(a)?
It decreases both LDL and Lipoprotein(a).
p.4
Clinical Disorders of Lipoprotein Metabolism
What clinical features characterize familial dysbeta-lipoproteinemia?
Fat deposits in palmar creases and tuberous xanthomata.
p.4
Familial Hypercholesterolemia
What are the typical plasma cholesterol concentrations in familial combined hyperlipidemia (FCH)?
Between 6 mmol/L and 9 mmol/L (230 – 345 mg %).
p.6
Genetic Causes of Dyslipidemias
Which genetic conditions are associated with low lipid levels?
Hypobetalipoproteinemia, abetalipoproteinemia, and Tangier disease.
p.6
Familial Hypercholesterolemia
What is abetalipoproteinemia inherited as?
An autosomal recessive trait.
p.2
Frederickson Classification of Dyslipidemias
How can the Fredrickson type change?
As a result of dietary or drug intervention.
p.1
Genetic Causes of Dyslipidemias
What are some genetic causes of dyslipidemias?
Primary dyslipidemias are often due to genetic factors.
p.5
Common Causes of Hyperlipidemias
What is the typical plasma cholesterol concentration in this condition?
Usually either mildly or moderately elevated.
p.8
Lipoprotein(a) Elevation
What effect does Lipoprotein(a) have on thrombogenesis?
It stimulates thrombogenesis.
p.5
Genetic Causes of Dyslipidemias
How can hyperalphalipoproteinemia be inherited?
As an autosomal dominant condition or may show polygenic features.
p.5
Clinical Disorders of Lipoprotein Metabolism
What is the relationship between plasma HDL concentration and cardiovascular disease?
There is no increased prevalence of cardiovascular disease; HDL is thought to be cardio protective.
p.6
Familial Hypercholesterolemia
What characterizes hypobetalipoproteinemia?
Decreased plasma LDL and cholesterol, but not absent; other lipoproteins are normal.
p.6
Secondary Hyperlipidemias
What secondary factors can lead to low HDL cholesterol levels?
Obesity, physical inactivity, cigarette smoking, diabetes.
p.2
Frederickson Classification of Dyslipidemias
What is the basis of the Fredrickson classification of dyslipidemias?
The appearance of a fasting plasma sample after standing for 12 hours at 4° C and analysis of its cholesterol and triglyceride content.
p.1
Diagnosis of Dyslipoproteinemias
What are the reasons for performing lipid measurements?
Screening for cardiovascular disease prevention, investigating lipid disorder features, and monitoring response to diet and medication.
p.7
Familial Hypercholesterolemia
What is Tangier disease characterized by?
Absence of HDL in plasma, deficiency of apolipoproteins A I and A II, low LDL, high triglycerides, and accumulation of cholesteroyl esters.
p.7
Lipoprotein(a) Elevation
What is the role of the enzyme LCAT?
It catalyzes the esterification of free cholesterol.
p.6
Familial Hypercholesterolemia
What is primary hypoalphalipoproteinemia characterized by?
Low HDL cholesterol levels.
p.4
Genetic Causes of Dyslipidemias
What is polygenic hypercholesterolemia?
A condition caused by complex interactions between multiple environmental and genetic factors.
p.1
Frederickson Classification of Dyslipidemias
What is the Frederickson classification used for?
To classify dyslipidemias based on increased plasma lipoprotein concentrations.
p.1
Clinical Disorders of Lipoprotein Metabolism
What are some clinical disorders associated with lipoprotein metabolism?
Coronary heart disease (CHD), acute pancreatitis, failure to thrive, and cataract.
p.5
Common Causes of Hyperlipidemias
What is a significant negative clinical finding associated with this condition?
The absence of tendon xanthomata.
p.8
Lipoprotein(a) Elevation
How does Lipoprotein(a) affect fibrinolysis?
It competes with plasminogen for its binding site, leading to reduced fibrinolysis.
p.6
Clinical Disorders of Lipoprotein Metabolism
What are some symptoms of abetalipoproteinemia?
Failure to thrive, fatty stools, abnormal red blood cells, decreased vision, mental retardation, ataxia, muscle weakness, slurred speech, scoliosis.
p.5
Secondary Hyperlipidemias
What are some causes of secondary hyperlipidemia with predominant hypertriglyceridemia?
Alcohol excess, obesity, diabetes mellitus, certain drugs, chronic kidney disease, some glycogen storage diseases, systemic lupus erythematosus.
p.3
Clinical Disorders of Lipoprotein Metabolism
What are common symptoms of chylomicron syndrome in children?
Abdominal pain and often acute pancreatitis.
p.3
Familial Hypercholesterolemia
What characterizes homozygotes for familial hypercholesterolemia?
Very rare (1 in 1,000,000), no receptors present, and plasma cholesterol can be as high as 20 mmol/L.
What are the two main types of hyperlipoproteinemia?
Primary hyperlipoproteinemia and secondary hyperlipoproteinemia.
p.1
Common Causes of Hyperlipidemias
What are common secondary causes of hyperlipidemias?
Nephrotic syndrome, hypothyroidism, type 2 diabetes, cholestasis, anorexia nervosa, drug-induced causes, hypertension, smoking, and alcohol abuse.
p.7
Common Causes of Hyperlipidemias
What effect do beta-blockers and anabolic steroids have on HDL cholesterol levels?
They can lower HDL cholesterol levels.
p.7
Common Causes of Hyperlipidemias
What are secondary causes of low plasma HDL cholesterol?
Tobacco smoking, obesity, poorly controlled diabetes mellitus, insulin resistance, chronic kidney disease, and certain drugs.
p.3
Familial Hypercholesterolemia
What is the primary cause of chylomicron syndrome?
Familial lipoprotein lipase deficiency, an autosomal recessive disorder.
What is hypolipoproteinemia?
A lack of fat in the blood due to genetic or other diseases such as malnutrition and malabsorption.
p.3
Clinical Disorders of Lipoprotein Metabolism
What are typical physical findings in chylomicron syndrome?
Eruptive xanthomata and hepatosplenomegaly.
p.8
Lipoprotein(a) Elevation
What is the range of Lipoprotein(a) concentration in plasma?
Between 0.2 and 200 mg/dl.
What are primary causes of low plasma HDL cholesterol?
Familial hypoalphalipoproteinemia, ApoA abnormalities, Tangier’s disease, LCAT deficiency, and Fish-eye disease.
p.4
Familial Hypercholesterolemia
What is another name for type three hyperlipoproteinemia?
Familial dysbeta-lipoproteinemia.
p.6
Common Causes of Hyperlipidemias
What symptoms are associated with hypobetalipoproteinemia?
Mild clinical findings similar to abetalipoproteinemia, but usually no symptoms requiring treatment.
