Lipids Total, Lipids Role in Our Body
Lipids Total
What sample is needed for Lipids Total?
- This is done on the patient’s serum.
- Fasting samples for 8 to 12 hours are needed.
What are the indications for Lipids Total?
- Total lipid is advised to assess lipid metabolism.
- It is helpful for the diagnosis of hyperlipidemia.
- These are advised for coronary disease.
- It is advised to assess the risk of atherosclerosis.
- It is also advised in stroke.
What are the precautions for lipid estimation?
- Abnormal lipid tests should always be confirmed with a new specimen.
- Preferably one week apart, before beginning or changing the therapy.
- If a tourniquet is applied for more than 3 minutes, it will lead to abnormal results. It will lead to a 5% variation in the values.
How will you define Lipids?
- Lipids are carbon- and hydrogen-containing compounds that are hydrophobic: insoluble in water and soluble in organic solvents.
- Biologically, groups are:
- Neutral fats (consists of fatty acids, primarily oleic acid, linoleic acid, stearic, arachidonic, and palmitic acid).
- Conjugated lipids.
- Sterols (biologically active cholesterol).
- The lipids are a heterogeneous group of compounds related more by their physical characteristics than their chemical properties.
- The lipids have the common properties:
- Relatively insoluble in water.
- Soluble in nonpolar solvents like ether, benzene, and alcohol.
- Lipids are essential dietary constituents due to their importance in:
- Fat-soluble vitamins.
- High energy.
- Essential fatty acids are present in natural foods.
- Lipids include fats, oils, steroids, waxes, and related compounds.
- The major lipids are:
- Cholesterol.
- Triglycerides.
- Phospholipid.
How will you discuss the absorption of fats in food?
- Absorption of fats occurs in three phases:
- Intraluminal phase, where the fats are modified both physically and chemically.
- Cellular phase or absorptive phase, where modified fat enters the intestinal mucosal cells.
- Transport phase, where the absorbed fats are transported through lymphatics and blood.
What is the importance of lipids in our body?
- Lipids serve as an efficient source of energy when stored in adipose tissue.
- Lipids serve as thermal insulators in the subcutaneous tissues and organs.
- Nonpolar lipids act as an electrical insulator, allowing the rapid progression of depolarization waves along myelinated nerves.
- The fat contents of the nerve tissue are high.
- The combination of lipids and protein as lipoproteins is an important cellular constituent.
- They are part of cell membranes and mitochondria within the cytoplasm.
- It is a means of transporting lipids in the blood.
- Lipids are important to understanding atherosclerosis, obesity, and polyunsaturated fatty acids in nutrients and health.
What are the properties of lipids?
- Lipids are soluble in organic solvents (ether, hexane, or chloroform) and insoluble in water.
- These are carbon and hydrogen-containing compounds and are mostly hydrophobic.
- Lipids are insoluble in liquid media like plasma. Therefore, these must be packaged into lipoprotein particles.
- Lipids have a hydrophilic exterior with the help of a phospholipid coat.
- The phospholipid layers have various types of apolipoproteins.
- In the central part of lipoproteins are cholesterol and triglycerides.
- Every lipoprotein contains:
- Cholesterol.
- Triglycerides.
- Phospholipids.
- Apolipoproteins
How will you discuss the metabolism of lipids?
- Lipids are synthesized from dietary fat.
- Ingested lipids are taken up by the intestinal epithelial cells and packaged into lipoproteins called chylomicrons.
- A chylomicron is the lipoprotein that transports lipids from the intestinal epithelium to other somatic cells, particularly liver cells, where these are endocytosed via apolipoprotein E.
- In the liver, cholesterol and triglycerides are packed into another type of lipoprotein called very low-density lipoprotein (VLDL), which is secreted into the blood.
- VLDL has an increased amount of Triglycerides (TG). VLDL is the means for the transport of TG to the other somatic cells.
- Hepatocytes also produce high-density lipoproteins (HDL).
What is the difference between chylomicrons and VLDL?
| Characteristic features | VLDL | Chylomicron |
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Liver | Gastrointestinal tract |
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It is seen in pre-beta | At the start |
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10% | 1% |
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60% | 90% |
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15% | 5% |
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15% | 4% |
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Transport endogenous triglycerides | Transport dietary triglycerides |
What is the important role of Lipids in life?
- These are precursors of hormones.
- Help with digestion.
- Provide a store of energy.
- They provide metabolic fuels.
- They are part of the cell membranes.
- Make certain hormones.
- Lipids yield fatty acids on hydrolysis.
- Lipids can form esters.
- Cholesterol and triglycerides are the main lipids measured in routine blood chemistry tests.
How will you classify lipids?
Lipids are a group of substances that consist of :
- Glycerol esters include:
- Triglycerides.
- Diglycerides.
- Monoglycerides.
- Phosphoglycerides.
- Free fatty acids.
- Phospholipids.
- Sterols include:
- Cholesterol
- Steroid hormone.
- Bile acids.
- Vit.D.
- Carotenoids.
- Vitamins A, E, and K.
Another classification of Lipids is as follows :
- Neutral fat consists of fatty acids (oleic, linoleic, Stearic, Arachidonic, and Palmitic acids) in triglycerides.
- Waxes.
- Phospholipids :
- Lecithin.
- Cephalins.
- Sphingomyelin.
- Glycolipids :
- Cerebrosides.
- Gangliosides.
- Lipoproteins.
- HDL
- HDL-Cholesterol
- LDL
- LDL-Cholesterol.
- VLDL
- Sterols:
- Cholesterol and esters (major biological significance).
- Steroids.
- Bile acids.
- Substances associated with lipids:
- Carotenoids.
- Vit. K.
- Vit. E.
- Lipids may be classified as:
- Simple lipids.
- Neutral fats.
- Waxes.
- Complex Lipids.
- Phospholipids.
- Glycolipids:
- Cerebrosides.
- Gangliosides.
- Lipoproteins.
- Simple lipids.
- Lipid-associated substances are :
- Triacylglycerols are the major component of most foods, typically making up more than 95 to 99% of the total lipids.
- Cholesterol and triglycerides are the main lipids measured in routine blood chemistry.
- Conjugated lipids are the combination of phosphate or sugar to lipid molecules.
Cholesterol
- It is the best-known steroid, and it has an association with atherosclerosis.
- Cholesterol is the precursor of other important steroids, such as bile acids, adrenocortical hormones, sex hormones, vitamin D, cardiac glycosides, plant sitosterol, and some alkaloids.
- Cholesterol is distributed in almost all of the body cells. It is abundant in the nervous tissue.
- It is the main component of lipoproteins.
- It is a major part of the cell membranes.
- It is found in animal fats but not plant fats.
What is the pattern of lipids on thin-layer chromatography?
Discuss lipids as lipoproteins with their properties?
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What are the important Facts about lipids?
- Lipids are carried in the blood by special proteins made in the liver. The two main forms of protein-bound cholesterol are called LDL and HDL cholesterol.
- Because they are water-insoluble, they are carried by proteins.
- Free fatty acids are present in very small amounts in the blood, bound to a loose complex with albumin.
- Major lipid components in the plasma are triglycerides, Cholesterol, and phospholipids.
- These are transported in the blood as lipoproteins, with large protein molecules as apolipoproteins.
- The largest and least dense molecule of lipoprotein is Chylomicron, and this is followed by:
- Very low-density lipoprotein (VLDL).
- Low-density lipoproteins (LDL).
- Intermediate density lipoproteins (IDL).
- High-density lipoproteins (HDL).
- Most of the triglycerides of non-fasting plasma reside in the chylomicrons.
- In fasting plasma, triglycerides are mostly VLDL.
- Most of the cholesterol is present in LDL.
- A small fraction of the cholesterol, 15% to 25%, is in HDL.
- Triacylglycerols are esters of three fatty acids and a glycerol molecule.
- The terms fat, oil, and lipid are often used interchangeably.
How will you define Hyperlipidemia?
- It is the presence of elevated or abnormal levels of lipids and lipoproteins in the blood.
- The peak level of raised lipids (Hyperlipemia) occurs 3 to 6 hours after the meal.
- Plasma cholesterol levels increase with age.
- In the latter half of pregnancy, plasma cholesterol is raised by about 30% above the woman’s normal level.
- Men’s cholesterol levels are higher than women’s.
- Lipids and lipoproteins are highly modifiable risk factors for cardiovascular disease.
- One of the most clinically relevant lipid substances is cholesterol, especially in atherosclerosis and cardiovascular disease.
- Hyperlipoproteinemia is elevated levels of lipoproteins.
What are the Functions of lipids?
- The main biological function of lipids is to store energy.
- Lipids form structural components of the cell membrane.
- Lipids form messenger and signaling molecules.
- Lipids can be easily stored in the body and serve as a source of energy.
What are the causes of raised levels of Lipids?
- In hypothyroidism, both free and ester-cholesterol are increased.
- In nephrotic syndrome, β-lipoprotein is significantly raised. Total plasma lipids exceed 2 g/dL, and the plasma is milky.
- The total cholesterol level of lipoid nephrosis is 300 to 1000 mg/dL.
- These are raised in Ketosis, generally in untreated Diabetes mellitus. The plasma lipid level ranges from 0.7 to 2.0 g/dL.
- In diabetes mellitus, the level reported reached 22 g/dL.
Now, assess the total lipids; mostly Cholesterol, Triglycerides, LDL, and HDL are advised.
Questions and answers:
Question 1: What is bad cholesterol?
It is LDL and VLDL. It can lead to atherosclerosis.
Question 2: What is good cholesterol?
HDL is good cholesterol, and it increases with exercise, and it prevents atherosclerosis.









