LEC LIPIDS PART 2 - LIPID DETERMINATION Flashcards
Disorders of lipids
Arteriosclerosis, obesity, hypertension, DIABETES MELLITUS and other abnormalities
Good prognosis if lipid
Early detection of deranged blood lipid profile
age for screening for lipid
20 years old, if the test is normal repeat again after 5 yrs
if not, depends on the physician
- Indications for Lipid Profile include:
- ⁃ Screening for primary & secondary
hyperlipidemias - ⁃ Monitoring for risk of atherosclerosis
3.⁃ Monitoring treatment of
hyperlipidemias/Dyslipidemia
preanalytical considerations
biological variations such as
- Age: cholesterol levels increase with age.
- Sex: women have lower level than men except in childhood & after early 50’s.
- Season: cholesterol levels are slightly higher in cold periods.
- Food intake: daily intake of fat increases cholesterol levels.
- Medical conditions: thyroid, liver, and kidney diseases
- Acute illness
- Life-style: higher in sedentary and poor diet habits
explain the cholesterol level in terms of age
it increases with age
describe the gender relation of cholesterol
women have lower level than men except in childhood and after early 50`s
high in menopausal stage
can season affect cholesterol?
higher in cold cholesterol
why do menopausal women has high chole or high lipid profile?
because estrogen came from chole, if the cholesterol are can’t be converted into estrogen any longer, it will be deposited and stuck in the blood stream elevating lipids in the body
daily intake of fat increases cholesterol levels
true or false
true
in hyperthyroidism, chole is low because?
because of fast metabolism
if we have liver disease, do we have high or low chole?
low, 85% of chole is produced by the liver. If the liver is defected, there will be no organ that will produce it
describe the lipid profile of chronic alcoholic patients
low
describe the lipid profile of moderate alcoholic patients
high
components that clears the chylomicron
lipoprotein lipase that are activated by apo C2
Patient should fast for ___hours before sampling
12
Chylomicrons are cleared within__hrs and their presence
after 12hrs fast is abnormal.
6-9
Posture: Decreases of as much_________ of TC, LDL-C, HDL-C and apo-A-1 and B
10 %
correct position of getting sample
supine and lying position
Patient to be seated for __ prior to sampling to prevent hemoconcentration.
5min
Prolonged venous occlusion leads to increase in cholesterol conc by _______.
venous occlusion means tourniquet
10-15%
Exercise: Mild exercise produces a slight decrease in
conc of _______________.
chole and triglycerides
Those who walk for about 4 hours each week have an average cholesterol ___ lower and HDL-C ___ higher than inactive persons
5%; 3.4%
lipids that has higher concentration in the midcycle of menstruation
plasma Cholesterol and Triglycerides
A high fat diet increases serum __
triglyceride
-Ingestion of monounsaturated fat reduces __.
cholesterol
__ conc is reduced when sucrose intake is reduced.
Plasma triglyceride
A high carbohydrate diet decreases the serum conc. of___
VLDL-C, TG,
cholesterol and protein.
Large protein meals at lunch or in the evening also ___ the serum
cholesterol for atleast 1 hour after a meal.
increase
In vegeterian individuals, conc. of LDL & VLDL-C are reduced by ___ and ____
LDL 37%
VLDL 12%
Smoking:
The plasma cholesterol, triglyceride and LDL cholesterol conc. are higher by about ___respectively in smokers
than in non smokers
3 %, 9.1 % and 1.7 %
cholesterol, 3 %,
triglyceride 9.1 %
LDL cholesterol 1.7 %
__ cholesterol is lower in smokers than in non smokers
HDL
When MODERATE amount of alcohol is ingested
for 1wk, the serum TG conc is increased by more than _________.
20 mg/dl
Prolonged moderate ingestion of alcohol may increase HDL-C conc
it will reduced the plasma concentration of
cholesterol ester transfer protein(CETP).
what sample can we use for lipid profile?
either plasma or serum
___ is preferred when lipoprotein are measured by ultracentrifugation and electrophoretic methods
Plasma
if plasma is used for lipid profile, what anticoagulant is the best choice?
edta
2 methods to detect lipoprotein using plasma
ultracentrifugation and electrophoretic methods
reference method for lipoprotein determination
ultracentrifugation
the only lipoprotein that is only in the origin during the electrophoresis
chylomicron
which sample tend to have lower concentration of lipids
venous or capillary?
and why?
capillary - same with glucose, because of water
an anticoagulant that will exert large osmotic effect
citrate
Citrate: exert large osmotic effect resulting in falsely __ plasma lipid and
lipoprotein concentration.
low
an anticoagulant that can alter electrophoretic mobility of
lipoproteins.
heparin
heparin can alter electrophoretic mobility of
lipoproteins because of its __
high molecular weight
electrophoresis is separation of components depending on the
sizes
EDTA plasma
are ___% lower than in serum.
3%
in terms of storing
TC, TG, HDL-C can be satisfactorily analyzed in ___ samples.
frozen
aside from total chole, hdl, and tg
-__ can also be measured in frozen samples.
Apolipoproteins
Cholesterol Estimation has 2 methods, what are they
chemical and enzymatic method
if we have a given serum and we need to convert it to plasma, what formula we should use?
serum x 3%
if we have plasma and we need to find the serum, what’s the formula
X 1.03
we store sample or plasma in what temperature for a long time
- 70*
we store sample or plasma in what temperature for a short time (1-2 months)
-2 *
what is the former reference method for chemical estimation
abell kendall method
3 steps of abell kendall method
- Cholesterol is HYDROLYZED with alcoholic KOH
- Unesterified cholesterol is EXTRACTED with petroleum jelly/Hexane
- Measured using the L-B Reaction (COLORIMETRY)
RESULT OF HYDROLYZING CHOLESTEROL
cholesterol ester AND FATTY ACIDS
removing cholesterol from fatty acids is
free cholesterols
how Liebermann-burchardt reaction works?
the unsterified extracted will combined with sulfuric acid and acetic anhydride to form a bluish green solution
unsterified Cholesterol + Sulfuric acid + Acetic anhydride bluish green solution
end product of liebermann-burchardt’s reaction
bluish green solution called Cholestadienyl monosulfonic acid
purpose of acetic anhydride and sulfuric acid
color developers
another chemical method for cholesterol estimation that only uses 2 steps
Bloors Method
Bloors Method: - Principle: 2 step
- Cholesterol is extracted using an alcohol ether mixture
- Measured using the L-B Reaction
in bloor’s method, the cholesterol is extracted using
alcohol ether mixture
in abell kendall method - the cholesterol is extracted using
petroleum jelly and hexane
in abell kendall method - the cholesterol is hydrolyzed using
alcoholic potassium hydroxide KOH
what is the principle of abell kendall method
3 step method - hydrolysis, extraction, colorimetry
what is the principle of enzymatic method
cholesterol oxidase method
Routine Lab - Assay of Choice for cholesterol
Cholesterol Oxidase Method
Cholesterol Oxidase Method is only specific for __
cholesterol esters
cholesterol esters are those cholesterols with ___
fatty acids
the cholesterol ester are hydrolyze by what enzyme to form free chole and fatty acids
cholesterol esterase
free cholesterol will be oxidized by what enzyme
cholesterol oxidase
free cholesterol will be oxidized by cholesterol oxidase to form
4 cholestene - 3 - one + h202