Disorders of lipid metabolism

Biochemistry for medical students

1. DISORDERS OF LIPID
METABOLISM
Muhammad Umer Zafar (2191)
Turan Kaya (2148)

2. INTRODUCTION
Lipid storage disorders (or lipidoses) are a
group of inherited metabolic disorders in which
harmful amounts of lipids(fats) accumulate in
some of the body’s cells and tissues.

People with these disorders either do not
produce enough of one of the enzymes needed
to metabolise lipids or they produce enzymes
that do not work properly.
Muhammad and Turan

3. ORGANS AFFECTED
Over time, this excessive storage of fats can
cause permanent cellular and tissue damage,
particularly in the:

Brain
Peripheral nervous system
Liver
Spleen
Bone marrow.
Muhammad and Turan

4. INHERITANCE
Lipid storage diseases can be inherited two
ways: Autosomal recessive inheritance occurs
when both parents carry and pass on a copy of
the faulty gene, but neither parent show signs
and symptoms of the condition and is not
affected by the disorder.

X-linked recessive (or sex linked) inheritance
occurs when the mother carries the affected
gene on the X chromosome that determines the
child’s gender and passes it to her son.
Muhammad and Turan

5. DISORDERS
Cholelithiasis

Obesity

Fatty Liver

Atherosclerosis

Muhammad and Turan

6. CHOLELITHIASIS
Cholelith, also known as Gall stones:
concretion composed of crystalline substances
(usually cholesterol, bile pigments, and calcium
salts) embedded in a small amount of protein
material formed most often in the gallbladder.

Occurrence has been linked to secretion by the
liver of bile that is saturated with cholesterol
and contains abnormally low levels of bile salts
and the phospholipid lecithin,
Muhammad and Turan

7. CHOLELITHIASIS
Biochemistry
Cholesterol deposits trigger inflammatory
process which leads to lowering of pH
eventually it decreases cholesterol solubility.
Therapy
Surgical Therapy
Systemic – derivatives of bile acids-
chenodeoxycolic acid and ursodeoxycholic acid
(Ursofalk)
Muhammad and Turan

8. OBESITY
Obesity, also called fatness, excessive
accumulation of body fat, usually
caused by the consumption of
more calories than the body can use.
The excess calories are then stored as
fat, or adipose tissue.
Muhammad and Turan

9. BIOCHEMICAL DIFFERENCES IN
FAT DEPOSITION
Muhammad and Turan

10. METABOLIC CHANGES IN
OBESITY
Muhammad and Turan
Adipocytes send signals that cause abnormal
metabolic changes such as:
Dyslipidemias: High triglycerides and low HDL
level.

Glucose intolerance: Because of insulin
resistance, there is build-up of glucose.

Insulin resistance

11. FATTY LIVER
Muhammad and Turan
Fatty liver, also known as fatty liver
disease (FLD) or hepatic steatosis, is a
reversible condition where in large
vacuoles of triglyceride fat accumulate
in liver cells via the process
of steatosis (i.e., abnormal retention
of lipids within a cell).

12. FATTY LIVER
Muhammad and Turan
Causes
Decreased synthesis of phospholipids due to
deficiency of
PUFAs (Polyunsaturated fatty acids)
Methylating factors (methionine, choline,
etc)
Decreased secretion of VLDL due to impaired
cytoskeleton by acetaldehyde (from ethanol
metabolism)
Stimulation of Ito cells (Hepatic Stellate
Cells HSC) and increases synthesis of
Extracellular Matrix (ECM) proteins – fibrosis
and cirrhosis.

13. ATHEROSCLEROSIS
Muhammad and Turan
Atherosclerosis (also known
as arteriosclerotic vascular
disease or ASVD) is a specific form
of arteriosclerosis in which an artery-
wall thickens as a result of invasion
and accumulation of white blood
cells (WBCs) (foam cell) and
proliferation of intimal-smooth-muscle
cell creating a fibro-fatty plaque.