Lipids

Question 1

6 analytes

Answer 1

cholesterol
fatty acids
glycerol esters
sphingolipids
lipoproteins
apolipoproteins

Question 2

Fatty acid chemical structure

Answer 2

CH3(CH2)nCOO-

Question 3

Family of nuclear receptors activated by FAs is called ____________

Answer 3

PPARs
proliferator-activated receptors

Question 4

PPARs are implicated in 2 pathologic processes:

Answer 4

insulin resistance
dyslipidemia

Question 5

Clinical significance of lipid and lipoprotein testing is mostly for

Answer 5

atherosclerotic diseases

Question 6

Definition of disorders of lipoprotein metabolism is based on relationship between

Answer 6

Definition is based on relationship between lipoprotein concentration and risk for CHD

Question 7

Indications for lipid profile (3)

Answer 7

• screening for primary and secondary hyperlipidemias
• monitoring for risk of atherosclerosis
• monitoring the treatment of hyperlipidemias

Question 8

_______ and __________ are the plasma lipids of most interest

Answer 8

Cholesterol
Triglycerides

Question 9

Biological variations (6)

Answer 9

increasing age
sex (women have lower level during mid-age)
food intake
medical conditions (thyroid, liver, kidney)
acute illness
life-style

Question 10

Patient should fast for _______ h

Answer 10

12h

Question 11

Plasma or serum can be used when ____, _____ and _____ are measured

Answer 11

TC
TG
HDL-C

Question 12

Plasma is preferred when ______ is measured

Answer 12

lipoprotein

Question 13

_______ is used when it is necessary to store samples for weeks/months

Answer 13

serum

Question 14

Measurements in the _______ samples seem to be little lower than _______ samples

Answer 14

Measurements in the capillary samples seem to be little lower than venous samples

Question 15

Frozen samples (4)

Answer 15

TC
TG
HDL-C
Apolipoproteins

Question 16

For short-time storage sample can be kept at _____

Answer 16

-20C

Question 17

The rate limiting enzyme in cholesterol metabolism is

Answer 17

3-hydroxy- 3-methylglutaryl coenzyme A reductase (HMG-CoA reductase)

Question 18

Fasting lipid panel should be done once every _____ years in adults aged more than _______

Answer 18

5 years
20 years

Question 19

If person has low risk, further testing is not required if total cholesterol ______ mg/dl and HDL more than ________ mg/dl

Answer 19

If person has low risk, further testing is not required if total cholesterol < 200 mg/dl and HDL more than 40 mg/dl

Question 20

Cholesterol assay-enzymatic method procedure

Answer 20

• Reagent is mixed with 3-10-pL aliquot of serum/plasma
• incubated under controlled conditions for colour developments
• absorbance is measured in the visible portion of the spectrum, generally about 500nm

Question 21

Interfering substances in enzymatic procedure are (3)

Answer 21

• bilirubin
• ascorbic acid
• hemoglobin

Question 22

Which substances react in cholesterol oxidase method?

Answer 22

cholesterol ester + H2O + cholesterol esterase -> free cholesterol
Hydrogen peroxide reacts with a compound giving coloured compound

Question 23

Cholesterol levels

Answer 23

Good level: below 200 mg/dl (low risk of heart disease).

Border line: 240mg/dl (if higher at high risk)

Less than 70 mg/dL for those with heart or blood vessel disease and for other patients at very high risk of heart disease (those with metabolic syndrome)

Less than 100 mg/dL for high risk patients (e.g., some patients who have multiple heart disease risk factors) if you have heart disease or diabetes.

Less than 130 mg/dL for individuals who are at low risk for coronary artery disease

LDL less than 160 mg/dL if you have 0 or 1 risk factor.

Question 24

Does measuring cholesterol blood level need fasting?

Answer 24

Cholesterol level is not affected by single meal but affected by long (change from high fat diet to low fat diet for several weeks) term pattern of eating

Question 25

Cholesterol level is _______ during pregnancy and _____ weeks after delivery

Answer 25

Cholesterol level is elevated during pregnancy and 6 weeks after delivery

Question 26

Some drugs which increase cholesterol are (6)

Answer 26

anabolic steroids beta blockers epinephrine oral contraceptives vitamin D

Question 27

Polyanion precipitation for estimation of lipoproteins

Answer 27

* Lipoproteins are precipitated with polyanions ( heparin sulfate, dextran sulfate and phosphotungstate) * Reaction should be in the presence of divalent cations Mg, Ca and Mn * Most commonly for HDL and is reasonably specific

Question 28

Lipoprotein electrophoresis is used to identify _____

Answer 28

rare familial disorders (Type I, III, V hyperlipidemias)

Question 29

How is HDL-C measured?

Answer 29

The concentration of HDL in plasma is usually assessed by determining the concentration of cholesterol associated with HDL. Basically, after the non-HDL lipoproteins are first physically removed or are effectively masked, total cholesterol is then measured.

Question 30

LDL-C estimation misclassifies 15-40% of patients when TG levels are between __________ mg/dl

Answer 30

200-400 mg/dl

Question 31

VLDL-C/Plasma TG ratio is useful in what pathological condition?

Answer 31

Type III hyperlipoproteinemia Type III have ratio > 0.689 (usually up to 0.0919)

Question 32

Triglycerides desirable level is below?

Answer 32

< 176 mg/dl (< 2.0 mmol/L)

Question 33

Apolipoproteins of clinical importance are (3) ?

Answer 33

Apo B, Apo A-1 and Lp(a)

Question 34

Apo B function

Answer 34

indicator of combined LDL and VLDL concentration

Question 35

Apo A-1 function

Answer 35

major protein of HDL

Question 36

Lp(a) funcion

Answer 36

variant of LDL, an independent indicator of CHD risk

Question 37

Half of all myocardial infarctions occur in individuals WITH/WITHOUT overt hyperlipidemia?

Answer 37

WITHOUT

Question 38

There is a significant association between _______ and future risk of metabolic syndrome, diabetes and hypertension

Answer 38

hsCRP (high-sensitivity C-reactive protein)

Question 39

CRP characteristics

Answer 39

It contains little or no carbohydrate and is synthesized in the liver. Its production is controlled by interleukin-6

Question 40

CRP test is based on the _______ ________ method

Answer 40

CRP Test is based on the latex agglutination method

Question 41

CDC/AHA assessment guidelines for CRP

Answer 41

Risk low if CRP < 1.0 mg/l Risk intermediate if CRP 1.0-3.0 mg/l Risk high if CRP > 3.0 mg/l

Question 42

Elevated homocysteine is associated with elevated risk of ?

Answer 42

Vascular and CV disease Other than that Hcy is also associated with: birth defects, pregnancy complications, psychiatric disorders, mental impairment

Question 43

Clinically measurement of tHcy is considered important to (3)

Answer 43

to diagnose homocystinuria ( no processing of methionine) to identify individuals with or at a risk of developing cobalamin or folate deficiency to assess tHcy as a risk factor for CHD.