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Sample

Precautions

  1. Patients must have at least fasting for 12 hours.
  2. If TG in male > 160  mg/dL and female > 135 mg/dL then two more samples should be done in next 6 to 8 weeks.
  3. Intake of the fatty meal may increase the TG.
  4. Alcohol intake increases the TG.
  5. In pregnancy, the TG level is raised.
  6. Take H/O drubs like oral contraceptive and estrogen increase the TG level.
  7. Take H/O ascorbic acid, clofibrate and colestipol decrease the TG level.

Indication

  1. This is done to evaluate the cases of atherosclerosis (Coronary artery disease).
  2. This is done to evaluate the turbid serum (milky).
  3. Triglyceride is part of lipid profile.
  4. Triglyceride advised in a patient with suspected fat metabolism disorder.

Pathophysiology                                                                                                                                                                                                 

  1. TG consists of three fatty acid + one molecule of glycerol by ester bond, so called as Triglycerides.
    1.  Glycerol and fatty acids building block for TG.
    2. Three fatty acids  + one molecule of glycerol (ester bond)  =  Triglyceride
    3. TG is present in the blood and transported by the VLDL and LDL.

    1. Glucose must be present in the cells for the formation of TG.
    2. There is Triglyceride formation by the glycolytic pathway in the glucose catabolism.
    3. This triglyceride formation may be absent in case of:
      1. Fasting.
      2. Starvation.
      3. Uncontrolled diabetes mellitus.

  1. TG when catabolized, it forms a small fraction of free fatty acid which appears in plasma bound to albumin.
    1. These nonesterified fatty acids after oxidation enter the Acetyl CoA cycle.
    2. The end result is water, CO2, and ATP which is the source of energy.

  1. TG is the fat in the bloodstream.
    1. TG accounts for more than 90 % of the food intake and is 95% of the fat stored.
    2. TG is insoluble in water and these are the main glycerol ester.
  2. TG is stored in adipose tissue as :
    1. Glycerol.
    2. Fatty acids.
    3. Monoglyceride.
  3. The liver is the factory to converts all above into triglycerides. 

                                                                                                                   Metabolism of Triglyceride in hepatocyte

  1. One of the sources gives the following ratio of triglycerides in various fats.

                                                                                                                                          Triglyceride

  1. TG are Transported and present in :
    1. 80 % are in VLDL.
    2. 15 % are in LDL.

  1. TG is the source of energy.
  2. When TG is high then starts depositing in fatty tissue.
  3. Source of Triglyceride:
    1. Plants contain polyunsaturated fatty acids.
      1. Corn.
      2. Sunflower.
      3. Safflower.
    2. Animal source contains mostly saturated fatty acids and solid at room temperature.
  4. The Fredrickson-levy classification method for hyperlipidemia:  Keep the plasma at 4 C refrigerate for 16 hours and then made an observation of the creamy layer at the top of turbidity.
    1. This can be completed by doing a lipid profile.

Normal Triglycerides

Source 1

Age  Male mg/dL  Female mg/dL
 Cord blood 13 to 95 11 to 76 
 0 to 9 year 30 to 100  35 to 110
 10 to 14 year 32 to 125  37 to 131 
 15 to 19 year 37 to 148  39 to 124 
 20 to 24 year 44 to 201  36 to 131
 25 to 29 year   46 to 249  37 to 144 
30 to 34 year 50 to 266 39 to 150
35 to 39 year 54 to 321 40 to 176
40 to 44 year 55 to 320 45 to 191
45 to 49 year 58 to 327 46 to 214
50 to 54 year 58 to 320 52 to 233
55 to 59 year 58  to 286 55 to 262
60 to 64 year 58 to 291 56 to 239
>65 year 55 to 260 60 to 240

Source 2

Children Male  mg/dL Female mg/dL
0 to 5 years 30 to 86  32 to 99 
6 to 11 years 33 to 108  35 to 114 
12 to 15 years 36 to 138  41 to 138 
16 to 19 years 40 to 163  40 to 128 mg 

Critical values are:

Triglycerides concentration according to the National cholesterol education program adult treatment panel (NECP-ATP II).

Concentration Serum Triglyceride mg/dL
Normal  <200
Borderline  200 to 400
High  400 to 1000
Very high >1000 


Increased Triglycerides values are seen in:

  1. Hyperlipidemia.
  2. Hyperlipoproteinemia.
  3. Nephrotic syndrome.
  4. Liver diseases.
  5. Alcoholism (alcoholic cirrhosis).
  6. Diabetes Mellitus, uncontrolled.
  7. Glycogen storage disease (Von Gierke disease).
  8. Familial hypertriglyceridemia.
  9. Hypothyroidism.
  10. Gout.
  11. Anorexia nervosa.
  12. Down’s syndrome.
  13. Myocardial infarction.

Decreased Triglycerides level is seen in:

  1. Malnutrition.
  2. Hyperthyroidism.
  3. Congenital α-β- lipoproteinemia.
  4. Malabsorption.

Management of Hypertriglyceridemia:

  1. If Triglycerides is < 200 mg/dL then the person needs diet control and he should be advised to repeat triglyceride once a year.
  2. If Triglycerides is 200 to 500 mg/dL then evaluate the patient with risk factors like:
    1. Diabetes mellitus
    2. Alcoholism
    3. Hypothyroidism
    4. Hypertension
    5. Hyperuricemia
    6. Medication like beta blockers, Estrogen, corticosteroids, oral contraceptives.
    7. Diseases like kidney, pancreatitis.
      1. No above risk factors in a person need only diet control
      2. Positive above risk factors and family history in a person needs diet and medication
  3. Critical value If triglyceride is >500 mg/dL in a person then these patients needs diet control and medication.

Table showing the summary of characteristics of the lipoproteins

Characteristics Chylomicron HDL LDL VLDL
Size (diameter nm) >70.0 4 to 10 19.6 to 22.7 25 to 70
Electrophoretic mobility Origin α - region β - region Pre - β region
Molecular weight  0.4 to 30 x 109 3.6 x 109 2.75 x 109 5 to 10 x 109
Synthesized in  Intestine Intestine and liver  Intravascular Liver and intestine 
Composition by weight in %        
                     Cholesterol esterified 5 38 49 11 to 14
                    Cholesterol unesterified 2 10  13 5 to 8 
                    Triglycerides 84 9 11 44 to 60
                    Phospholipids 7 22 27 20 to 23
                    Proteins 2 21 23 4 to 11


Possible References Used

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