Biochemistry Lipids Flashcards Preview

Cardio > Biochemistry Lipids > Flashcards

Flashcards in Biochemistry Lipids Deck (59)
Loading flashcards...
1
Q

Lipoproteins: types

A

Bad (Non-HDL)

Good

2
Q

Bad (Non-HDL)

A

Chylomicron and Chylomicron remnant
VLDL Very low Density lipoprotein
IDL – Intermediate Density lipoprotein
LDL – Low density lipoprotein

3
Q

Good

A

HDL – High density Lipoprotein (cholesterol rich)

4
Q

IDL only present in

A

Significant amounts in disease – Type 3 hyperlipidaemia

→ Usually not present

5
Q

Chylomicron

A

Normally present after a meal

Abnormal in fasting state – Type 1 Hyperlipidaemia

6
Q

LDL calculation

A

TC – HDL – TG/2.2

7
Q

LDL cholesterol target

A

2 mmol/l

8
Q

NON HDL calculation

A

TC-HDL

9
Q

Non HDL target

A

2.5 mmol/l

10
Q

Bad non HDL includes

A

VLDL and LDL

11
Q

Total cholesterol includes

A

VLDL, LDL and HDL

12
Q

Metabolism of Exogenous and Endogenous Fat

A
  1. Dietary fat is transported via chylomicrons across the epithelial wall.
  2. Lip Lipase hydrolyses FFA
  3. FFA (from triglyceride)
  4. Chylomicrons and TG produce VLDL = produces IDL to LDL
13
Q

What can go wrong:

A
  1. Eat too much → push too much through pathway
  2. Overweight – over production of VLDL (liver)
  3. Diabetes: over production
  4. Smoke – LDL
  5. Genetic – Familial hypercholestreamia
14
Q

HDL Metabolism:

A

➢ Apo A1 gathers Cholesterol from a peripheral (macrophages) (ABCA1 – gets energy for ATP – aids binding of cholesterol) produces HDL
➢ HDL is taken up by the liver in SRB1 (receptor ligand)
➢ High levels are good.

15
Q

Total Cholesterol
Normal/Average
Ideal/Target

A

5.9

<4

16
Q

Triglyceride
Normal/Average
Ideal/Target

A

<1.2

17
Q

HDL Cholesterol
Normal/Average
Ideal/Target

A
  1. 2 (M) 1.4 (F)

1. 2-2

18
Q

LDL Cholesterol
Normal/Average
Ideal/Target

A

4

<2

19
Q

Non-HDL cholesterol
Normal/Average
Ideal/Target

A

4.5

<2.5

20
Q

Who to test

A

➢ CVD or at risk (family history; diabetes; age >50)

21
Q

Measuring TG’s vs total cholesterol process

A

➢ Fasting essential for accurate measurement of TG’s, but makes little difference to total cholesterol

22
Q

To calculate LDL

A

➢ Need fasting profile and TG <4 to calculate LDL

23
Q

To pick up mixed hyperlipidaemia

A

➢ MST measure full profile (Chol; Trig; HDL at least once before starting Rx –to pick up mixed hyperlipidaemia)

24
Q

Measuring Chol and HDL

A

➢ (and therefore Non-HSL cholesterol) on non-fasting sample

25
Q

Post trauma or MI

A

➢ NB Chol FALLS by -30% in 24 HRs for 3/12 months after MI

26
Q

Secondary Causes of High cholesterol measure first:

A
  1. Glucose
  2. LFT’s
  3. U and E
  4. TSH
  5. Dipstick urine
27
Q

Cholesterol (High)

A

Accelerated atherosclerosis

28
Q

Low HDL leads to

A

Accelerated atherosclerosis

29
Q

Triglyceride

A

2-10 mmol/l – accelerated atherosclerosis

>10 mmol/L – acute pancreatitis

30
Q

Secondary Causes of High cholesterol

A
Diabetes
Liver disease
Renal disease
➢	Nephrotic syndrome
Hypothyroidism
Alcohol
HIV
Anorexia
Drugs:
➢	Ani retrovirals
➢	Retinoids
➢	Steroids (anabolic)
➢	Antidepressants
➢	Pscyhotrophics
31
Q

Test before treating

A
  1. Glucose
  2. LFT’s
  3. U and E
  4. TSH
  5. Dipstick urine
32
Q

Primary (Monogenic) Hyperlipidaemia

A

➢ Familial Hypercholestraemia
➢ Familial combined hyperlipidaemia
➢ Type III hyperlipidaemia
➢ Severe Hypertriglyceride

33
Q

Familial Hypercholestraemia: Genetics

A

Autosomal dominant, 1:500

34
Q

Familial Hypercholestraemia:Cholesterol typical levels

A

> 7.5

35
Q

Familial Hypercholestraemia: Triglyceride levels

A

Normal

36
Q

Familial Hypercholestraemia: Defect seen in one of the following genes

A

LDL receptor
Apo B
PcSK9 defect (breakdown role)

37
Q

Familial Hypercholestraemia:Signs

A

Tendon xanthomata

Corneal arcus

38
Q

Familial Hypercholestraemia: CHD event by and in

A

50% CHD events by age of 55 if untreated

39
Q

Familial Hypercholestraemia:Diagnosis in

A

25% of patients

40
Q

Familial Hypercholestraemia: Prognosis

A

Normal lifespan with treatment

41
Q

Familial Hypercholestraemia: Rx

A

Diet and statins

42
Q

Familial Combined Hyperlipidaemia:Genetics

A

Autosomal dominant

43
Q

Familial Combined Hyperlipidaemia:Cholesterol levels

A

Typically 5-10 mmol/L

44
Q

Familial Combined Hyperlipidaemia:Triglyceride levels

A

5-10 mmol/L

45
Q

Familial Combined Hyperlipidaemia:Prognosis

A

Aggressive CHD in middle age

46
Q

Familial Combined Hyperlipidaemia:Treatment

A

statins

47
Q

Type 3 Hyperlipideamia: Cholesterol levels

A

5-15 mmol/L

48
Q

Type 3 Hyperlipideamia: Causes/Genetics

A

Apo E2:E2 plus (doesn’t bind to receptor normally)

Alcohol XS or poor diet

49
Q

Type 3 Hyperlipideamia: Signs

A

Palmar crease xanthomata

Periheral vascular disease also

50
Q

Type 3 Hyperlipideamia: Consequences

A

CHD

PVD

51
Q

Type 3 Hyperlipideamia: Treatment

A

Statin and /or Fibrates

52
Q

Type 3 Hyperlipideamia:Epi

A

Rare (need another factor e.g. diabetes/poor diet) to trigger process

53
Q

High Triglyceride: Triglyceride levels

A

> 10 mmol/L

54
Q

High Triglyceride:Pathology

A

Lipoprotein lipase deficiency (Type 1 hyperlipideamia)

55
Q

High Triglyceride: Signs

A

Eruptive xanthomata

Lipaemia retinalis

56
Q

High Triglyceride: Risk of

A

Acute pancreatitis

57
Q

High Triglyceride: Treatment

A

Fibrates

58
Q

Drug treatment:

A
  1. HMGCoA reductase inhibitors (Statins)
  2. Fibrates
  3. Cholesterol absorption inhibitor (Ezetimibe) (2nd line for high cholesterol)
  4. Fish oils (Omacor) (2nd line high triglyceride)
  5. Bile acid sequestrants
59
Q

Drugs In Development:

A

➢ MTP inhibitors (reduce VLDL synthesis) – homozygous hypercholestraemia
➢ Glybera (Lipoprotein lipase gene replacement) – for patients with severe recurrent pancreatitis
➢ CETP inhibitors (raise HDL)
➢ PCSK9 inhibitors (increase LDL clearance)

Decks in Cardio Class (108):