The document provides an overview of lipids and lipoproteins. It defines lipids as biological compounds that are insoluble in water but soluble in organic solvents. The main classes of lipids are triglycerides, cholesterol, phospholipids and glycolipids. Lipids serve important functions like energy storage, cell membrane structure, and transport. The document discusses the structure and function of various lipoproteins involved in lipid transport, such as chylomicrons, VLDL, LDL, and HDL. It also covers lipid and lipoprotein measurement methods as well as their roles in health and disease.

1. Merlyn A. Baraclan,
RN, RMT

2.  Overview on Lipids
 Lipoproteins,
Apoliporoteins &
Related Proteins
 Lipid Transport &
Lipoprotein Metabolism
 Lipid & Lipoprotein
Measurement
 The NCEP Guidelines
 Lipids, Lipoproteins &
Disease
 References

3.  are biological
compounds
which are
soluble in
nonpolar organic
solvents but
relatively
insoluble in
polar solvents.

4. Triglycerides / TAG / TG
Cholesterol / C
Phospholipids
Glycolipids

5.  Primary source of fuel
 Components of cell membranes & many
cell structures
 Provide stability to cell membranes
 Means of transmembrane transport

6.  The function of lipoprotein particle is to
transport lipids around the body in the
blood.
Contain cholesterol in 2 forms:
_ free cholesterol
_ cholesterol ester
 Lipoproteins have a micellar structure.

7.  The transport proteins of lipids having a
micellar structure composed of two
parts as follows:
Central core
 contains TAG and cholesterol ester
 nonpolar moiety
Surface coat
 contains PL, free cholesterol, and
apolipoproteins

8. - Chylomicrons (CM)
- very low density lipoproteins
(VLDL)
- low density lipoproteins (LDL)
- high density lipoproteins (HDL)

9. CLASS DENSITY
(g/ml)
MEAN
DIAMETER
(mm)
source Principal
function
Electropho
retic
mobility
CM < 0.95 500 intestine Transport of
Exogenous
TAG
Remains at
Origin
VLDL 0.96 -1.006 43 liver Transport of
Endogenous TAG
Pre β
IDL 1.007-1.019 27 Catabolism of
VLDL
Precursor of LDL “broad β”
LDL 1.020-1.063 22 Catabolism of
VLDL via IDL
Cholesterol
Transport
β
HDL 1.064-
1.210
8 Liver,intestine,
catabolism of
CM & VLDL
“reverse
cholesterol
transport”
α

10. CLASS PROTEIN
%
TAG
%
CHOLESTEROL
%
PHOSPHO
LIPID
%
Chylomicron
/ CM
1-2 85 - 95 3 -5 5 -10
VLDL 10 60 -70 10 -15 10 – 15
LDL 15 -25 5 - 10 45 20 -30
HDL 50 Very
little
20 30

13.  MAJOR LIPOPROTEINS
1. CHYLOMICRONS / CM
- Produced by the intestine
- Transport lipids of dietary origin
- Poor in free cholesterol
- Has a “very high lipid/protein ratio
- “milky plasma”
- “Floating creamy layer”
- Removed by the liver

14.  2. VERY LOW DENSITY LIPOPROTEINS / VLDL
- Produced by the liver
- Supplies the body w/ TAG of endogenous
origin & also cholesterol
- “ turbid plasma”

15.  3. LOW DENSITY LIPOPROTEINS / LDL
- Produced by the metabolism of VLDL
- The particles do not scatter light
- Removed by the liver & macrophages

16.  4. HIGH DENSITY LIPOPROTEIN / HDL
- Consists mostly of proteins
- Produced by the liver
- “reverse cholesterol transport”
- Cardioprotective

17.  1. Lipoprotein (a) / Lp (a)
- Similar to LDL
- Synthesized in the liver
- “lipid staining pre β band”
- Has atherogenic properties
- 2. LPX Lipoprotein
- Seen in patients with obstructive biliary disease,
& with LCAT deficiency
- 3. β – VLDL
- “Floating β lipoprotein”

18. Food intestinal absorption
CM High TAG,Low Chol, Apo B48
TAG in adipose tissue
Muscle & FFA
chylomicron remnants taken by the liver

19. FFA TAG synthesis in liver, intestine VLDL
High TAG
Low Chol
FFA Apo B100
LPL Apo E
IDL
Apo E Binds onto hepatocytes through Apo E
LDL LDL binds to the receptors in liver (70%)
& other tissues (30%)

20. liver secretes Apo A1 + other Apos + PLs Nascent HDL
Cholesterol from tissues
HDL 3
Esterification of Cholestrol by LCAT
LDL
uptake by liver
Cholesterol transfer to VLDL
excretion into bile

21.  BIOLOGIC VARIATION
 FASTING
 POSTURE
 VENOUS VS. CAPILLARY
 PLASMA VS. SERUM
 STORAGE

22.  BIOLOGIC VARIATION
- Cholesterol level rises w/ age
- Women have lower levels than men
(except in childhood & after the early
50’s)
- Age related variation is the basis of
NCEP recommendation that
cholesterol screening be repeated
every 5 years.

23.  FASTING
- 12 hours before venipuncture
- Chylomicrons are completely cleared w/in 6
– 9 hours
- NCEP Adult Treatment Panel III( ATP III), has
recommended that patients fast for at least
9 hours before blood specimens are taken for
lipid & lipoprotein analysis
 POSTURE
- Current NCEP guidelines recommend that
patients be seated for 5 minutes prior to
sampling.

24.  VENOUS VS. CAPILLARY SAMPLES
- Measurements in capillary blood samples are
lower than venous samples & tend to be
more variable.
 PLASMA VS. SERUM
- Either plasma or serum can be used when
only TAG, cholesterol & HDL are measured, &
LDL – C is calculated from these three
measurements.
- Plasma is preferred when lipoproteins are
measured by ultracentrifugal or
electrophoretic methods

25.  PLASMA VS. SERUM Cont.
- EDTA is the preferred anticoagulant - ♥
- Heparin – X
- Citrate – X
 STORAGE
- When serum or plasma must be stored for
long periods it should be maintained at a
temperature of -70⁰C.
- For short term storage, the samples can be
kept at – 20⁰C.

26.  A. TAG measurement
Chemical Nonenzymatic Methods
General Steps
1. Extraction
- To remove TAG from LP’s
- Accomplished by using MeOH, EtOH,
isopropyl alcohol, Folch’s rgt & diethyl
ether
- - removal of interferences by zeolite

27. 2. Hydrolysis of TAG into FFA & Glycerol
- By saponification w/ alcoholic KOH
3. Measurement of Glycerol
- The glycerol liberated is oxidized by
periodate to HCHO & quantified by using any
of the ff:
- Eegrine reaction
- Schryver’s reaction
- Pay’s reaction
- Hantzsch reaction (method of choice)

28.  Enzymatic Methods
- Based on the hydrolysis of TAG & the
measurement of glycerol that is released in
the reaction:
LPS
- TAG + 3H2O glycerol + fatty acid
- Methods:
- Boculo David
- Megraw
- Winartasaputra
- Nagele - Trinder

29.  Chemical Nonenzymatic Methods
4 General Steps
1. Extraction
- Using Bloor’s rgt (3:1 EtOH – ether) or
zeolite extraction
2. Saponification
- Using KOH
3. Purification
- Using digitonin
4. Color development
- May proceed w/ the Leibermann-Burchardt
reaction or Salkowski reaction

30.  Leibermann - Burchardt reaction
- Uses sulfuric acid & acetic anhydride to
produce an unstable green cholestadienyl
monosulfonic acid; color stabilized by sodium
sulfate
 Zak or Salkowski reaction
- Uses sulfuric acid & ferric ions to produce a
stable red to red – violet cholestadienyl
disulfonic acid

31.  1 Step Methods
- Zlatkis – Zak Boyle method
- Ferro – Ham method
- Pearson – Stern – MacGavack
- Wybenga et al
 2 Step Methods
- Carr – Drekter
 3 Step Methods
- Abell – Kendall method (Standard reference
method)
 4 Step Methods
- Schoenheimer – Sperry
- Parek – Jung
- Sperry - webb

32. cholesterol ester
Cholesterol ester + H2O cholesterol + FFA
hydrolase
cholesterol
Cholesterol + O2 cholest – 4 – en – 3 – one + H2O2
oxidase
peroxidase
H2O2 + phenol + 4 aminoantipyrine quinoneimine dye
+ 2 H2O

33.  1. HDL Measurement
- Polyanion precipitation
- Electrophoresis – spectrophotometric det’n
- Ultracentrifugation ( reference method)
 2. Chylomicrons / CM
- Standing Plasma Test
 3. Lipid Profile
- Use of the Friedewald equation

35.  Testing & Treatment
Cholesterol Goals:
ATP III recommends a complete lipoprotein
profile as the initial test for evaluating blood
cholesterol.
Testing should be performed on all adults aged
20 & older & should be repeated once every
5 years.
The need for a therapeutic lifestyle change &
drug therapy

36. For Cholesterol: conversion factor to convert mg/dL to mM is 0.02586
For triglyceride : conversion factor to convert mg / dL to mM is 0.011
LDL Cholesterol HDL
Cholester
ol
Total
Cholesterol
Triglyceride
<100 optimal < 40 low < 200 desirable < 150 normal
100-129 Near
optimal /
above
optimal
≥ 90 high 200-
239
Borderline
high
150 -
199
Borderline
high
130-159 Borderline
high
≥ 240 high 200 -
499
high
160 -
189
High ≥ 500 Very high
≥190 Very high

37. Drug Class Mechanism of Action Example
Statins Lowers LDL cholesterol Lovastatin , simvastatin,
Pravastatin, fluvastatin
Fibric acid
derivatives
Lowers TAG Gemfibrosil, Fenofibrate
Bile acid
resins
Lowers LDL cholesterol Colestipol, cholestyramine
Niacin
(nicotinic
acid)
Lowers TAG niacin

38.  CHD
(coronary heart
disease)
 Atherosclerosis

39. Positive
Age: Male 45 yrs and above, Females 55 yrs
and above or premature menopause
without estrogen therapy
Family history of premature CHD
Current cigarette smoking
Hypertension (equal or more than 140/90
mmHg or on antihypertensive therapy)
Low HDL-Chol (<35 mg/dl)
Diabetes mellitus
Negative
High HDL-Cholesterol (equal to or above 60
mg/dl)

40.  hyperbetalipoproteine-
mia
 Elevated LDL – C
 Normal TAG
 High cardiac risk
 Commonly encountered
 SPECIFIC DISEASES
- Polygenic (Nonfamilial)
Hypercholesterolemia
- Familial
hypercholesterolemia/FH
- Familial Defective Apo B
- Sitosterolemia

41.  Due to the elevation
of TAG rich particles
 Hyperprebetalipo –
proteinemia
 secondary to excess
alcohol & high
carbohydrate intake
 SPECIFIC DISEASES
- Diabetic dyslipidemia
- Familial
hypertriglyceridemia
- Lipoprotein lipase
deficiency
- Apo C II deficiency
- Apo C III excess

42. A group of inherited disorders
characterized by the accumulation of
lipids in tissues especially the “brain”
due to a deficiency in a particular
sphingolipid catabolic enzyme

43.  Niemann – Pick disease
- Deficiency in sphingomyelinase & accumulation
of sphingomyelin
 Gaucher’s disease
- Deficiency in β – D glucosidase & the
accumulation of glucocerebroside
 Krabbe’s disease
- Deficiency in β – D galactosidase & the
accumulation of galactocerebrosides
 Fabry’s disease
- Deficiency in α – D galactosidase & the
accumulation of ceramide trihexoside
 Tay – Sach’s disease
- Deficiency in β – D hexaminidase & the
accumulation of β - sulfogalactocerebroside

44.  Ultracentrifugation & electrophoretic techniques are
of historical significance, MOST useful lipid &
lipoprotein testing are now enzymatic.
 LDL – cholesterol can be measured directly , but is
usually calculated using the Friedewald formula.
 LDL – C is now considered the MOST important
value in assessing cardiac risk & directing therapy.
 The profile for initial adult screening aged 20 &
above, includes TC, TAG, HDL – C & LDL – C &
should be repeated every 5 years.

45.  INTERNET SOURCES
 Bhagavan NV (2002). Medical Biochemistry.
San Diego: Harcourt/Academic Press.
ISBN 0-12-095440-0.
http://books.google.com/?id=vT9YttFTPi0C
&printsec=frontcover.
 http://biology.clc.uc.edu/courses/bio
104/lipids.htm
 BOOK SOURCES
 Clinical Diagnosis and Management
by Laboratory Methods / John
Bernard Henry. 20th ed. 224 – 248
Henry’s Clinical Diagnosis and
Management by Laboratory Methods
/ Richard McPherson & Mathhew
Pincus. 21st ed. 200 – 219
 Clinical Chemistry:
Principles, Procedures &
Correlations / Michael Bishop, Janet
Engelkirk & Edward Fody. 4th ed. 232
– 259
 Southwestern University College of
Medical Technology Clinical
Internship Manual / 2005 ed.
 Southwestern University College of
Medical Technology: Lecture Handbook
in Routine Clinical Chemistry/ Julius
Mario. 2008 ed. 44 -54
 Danny Donor ♥

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