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LOW DENSITY LIPOPROTEINS &
HIGH DENSITY LIPOPROTEINSHDLs
Triglyceride from unsaturated fats combine withcholesterol and proteins form HDL
Transport cholesterol from the body tissues to theliver
Have greater proportion of proteins
Reducing the depositing of cholesterol Exercise tends to increase HDL
Smoking reduces HDL
HDL help to remove cholesterol from the plaque
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LDLs Triglycerides from saturated fats combine with
cholesterol and proteins form LDLs
Major cholesterol carriers in the blood
Have lower proportion of proteins Increases the formation of fatty plaques of
atherosclerosis
Excess LDLs overload membrane receptors Receptors help to remove LDL from the blood
Saturated fats also interfere with LDL receptors
and elevates the risk of atheroma formation
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Apolipoproteins
Protein components of lipoproteins
Formed in the liver and intestine
Stabilizing the structure of lipoproteins andrecognizing receptors involved in lipoprotein
uptake
Different forms of apolipoproteins are ApoA,Apo B and Apo E
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Apo A- Major protein in HDLHelps to remove cholesterol from blood tothe liver
Apo B- Major protein in LDLTransfers cholesterol from the blood tocells
Apo E- Major component of HDLs and VLDLsInvolved in the removal of excess
cholesterol from the blood to the liverIt has three alleles producing three forms of proteins-E2,E3 and E4
E4 slows the removal of cholesterol from the blood
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Cholesterol & CVDs
High level of LDLs in the blood increases the
risk of CVDs
High level of HDLs in the blood decreases the
risk of CVDs
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Positive and negative correlation
Correlation-A change in one variable is reflected bya change in another variable
Causation-A change in one variable is responsiblefor a change in another variable
Positive correlation-Increase in one variableincreases another variable
Negative correlation-Increase in one variabledecreases another variable
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Cholesterol and CVD
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There is a positive correlation between
the level of LDL concentration in bloodand risk of CVD-As LDL level increases
risk of CVD also increases
A negative correlation between HDLconcentration in blood and risk of CVD
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Framingham Heart study
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Study to find out relation of HDL and LDL
in coronary artery disease
The study involved 5209 men and womenbetween the ages of 30 and 62 from the
town of Framingham, Massachusetts
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The result of the study indicates,
The lower the HDL-C level,the greater is therisk of developing CAD
The higher LDL-C level,the greater is the risk
of developing CAD
The risk nearly reaches three fold when LDL-
C is 220 mg/dl and HDL-C is 25 mg/dl
HDL-C remains an important risk factor even
in patient with a low LDL-C level
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Prospective Cardiovascular Munster
study
Confirms Framingham data
It showed that the incidents of CHD decreasedwith increasing high density lipoprotein
cholesterol
Study includes 4407 Germen men aged
between 40 to 65 followed for 6 years
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There is a clear link
between LDL/HDL ratioand death from CHD
A LDL/HDL ratio above 4.0drastically increases therisk of death from CVD