Outline of Today’s lecture
1. Introduction of Triglyceride
2. Clinical significance of Triglyceride
3. Principle of Triglyceride estimation
Objectives
 To determine serum Triglyceride level
 Master how to determine the conc. of
Triglyceride in serum.
 Understand the clinical significance of
Triglyceride
What are triglycerides?
• A triglyceride is an ester formed from glycerol
and three fatty acid groups. Triglycerides are
the main constituents of natural fats and oils.
The major lipids present in the plasma are fatty
acids,
triglycerides,
cholesterol
and
phospholipids.
Triglycerides consist of glycerol esterified with
three long-chain fatty acids, such as stearic
acid (18 carbon atoms) or palmitic (16 carbon
atoms) acids.
Triglyceride is present in dietary fat, and can be
synthesized in the liver and adipose tissue to
provide a source of energy, which can be
mobilized when required, for example, during
starvation.
Triglycerides containing both saturated
and unsaturated fatty acids which are
important components of cell membrane.
Triglycerides are the main constituents of
vegetable oil and animal fats. They are a
major component of human skin oils.
Lipoprotein Structure and Composition
Roles of Triglycerides
Fat stores
– Energy
– Protection- fat layer protect organs
– Insulation- fat does not conduct heat
© 2006 Thomson-Wadsworth
Causes of High Triglycerides
High carbohydrate diets
Several diseases (type 2 diabetes, chronic
renal failure, nephrotic syndrome)
Certain drugs (corticosteroids, estrogens,
retinoids, higher doses of beta-blockers)
Various genetic dyslipidemias
Physical inactivity
Cigarette smoking
Increased Triglycerides Occur With The
Following Conditions:
Hyperlipoproteinemia type II, IIb, III, IV,
and I.
Liver disease, alcoholism.
Nephritic syndrome, renal disease.
Myocardial infarction.
Hypothyroidism.
Decreased Triglyceride Levels Occur
With The Following Conditions:
Congenital α-β-lipoproteinemia.
Malnutrition.
Hyperthyroidism.
Recent weight loss.
Chronic obstructive lung disease.
How can you low high triglycerides?
You can make diet and lifestyle changes to
help lower your levels.
Stay at a healthy weight.
Limit fats and sugars in your diet.
Be more active.
Quit smoking.
Determination of serum Triglyceride
Types of Samples:
Plasma
Water + solids (e.g. glucose, urea, albumin, fibrinogen)
No cells
Serum
Serum = plasma – clotting factors
Requirements
Requirements:
Automatic pipettes
Tips
Cuvettes
 Spectrophotometer
 Reagents
Specimen:
Serum or plasma
Preparation of Cuvettes
Procedure
Blank
(only Reagent)
Standard
(Reagent+ St. sample)
Sample
(Reagent+Serum)
Triglyceride
Lipase
Glycerol + ATP Gk
Glycerol + Fatty acids
Glycerol-3-phosphate + ADP
Glycerol-3-Phosphate + O2
GPO
Dihydroxyacetone-phosphate + H2O2
2H2O2 + 4-aminoantipyrine + 4-chlorophenol
POD
Quinoneimine + HCL + 4H2O
Procedure
Kit Method
Reagents
Blank
Sample
Standard
Sample (ml)
-
10
-
Standard (ml)
-
-
10
Working reagent (ml)
1
1
1
Procedure
Add the reagents and sample as directed
Mix and let stand at room temperature for 10 min.
Read the absorbance at 505 nm (495-550).
Zero the spectrophotometer with the blank reagent.
Read the absorbance's of the standard and samples
within 1 hr
Enter the absorbance's readings and calculate the
concentration of the sample.
Calculations:
Concentration of the sample (s) =
Absorbance of the sample X Conc. of the Std.
Absorbance of the standard
50 – 150 mg/dl
Clinical
Interpretation
Abnormal
???
Level mg/dL
Level mmol/L
<150
<1.7
200-499
2.26–5.65
Interpretation
Normal range, low risk
Some risk