Dyslipidemia and CVD Part 2 Flashcards
What are the benefits of weight loss of 2-7kg in terms of blood lipid profile?
- decreased LDL-C by 0.1 mmol/L initially, variable afterwards
- decreased HDL-C by 0.03 mmol/L during loss, then increase by 0.4 mmol/L during maintenance
- decreased TG by 0.07 mmol/L
What are the benefits of physical activity in terms of blood lipids?
- 1200-2000 kcal/week
- decreased TG by 4-37%
- increased HDL by 2-8%
- decreased LDL by 0-7%
- improvements accentuated with weight loss
- volume/intensity of exercise has the greatest benefits
- resistance has little effect
- modest exercise can prevent deterioration
What are the predictive equations of effects on diet on serum total cholesterol?
KEYS
HEGSTED
What are the limitations of Predictive Equations?
- different have different effects
- predicts total cholesterol only - not lipid functions
- assumes MUFA and CHO are neutral
- effects on total cholesterol may not be linear
What is the 7 countries study?
- east Finland had the highest coronary deaths
- Ushibuka has the lowest coronary deaths
- Focus was Crete - mediterranean diet!!
What is dietary cholesterol and what is its impact on blood cholesterol levels?
- found only in animal foods
- less of an effect on raisin blood cholesterol than saturated fats but may be significant in some individuals
- very heterogenous responses to dietary cholesterol
What are the independent mechanisms of dietary cholesterol?
– Decreased synthesis and activity of hepatic LDL receptors
– Increased cholesterol in chylo and chylo remnants –> more atherogenic and increased chol delivery to liver
– Increased cholesterol in VLDL and VLDL remnants –> more atherogenic
– Cholesterol release to arterial wall during TG hydrolysis
– Interferes with ability of HDL to clear cholesterol
Saturated fats reduce the activity of LDL receptors by?
– Decreasing transcription of LDL receptor gene
– Altering PL composition of cell membranes to decrease binding
– Altering LDL itself and delays binding to receptors
What are the major sat. fat sources in the diet?
baked goods and processed foods
What are medium chain sat fats?
caprylic (8)
caproic (10)
What are intermediate chain sat fats?
lauric (12)
What are long chain sat fats?
myristic (14)
palmitic (16)
stearic (18)
How do sat fats affect blood LDL levels?
Different SFAs have different effects on blood LDL-C levels
– SFAs from dairy products ↓CVD risk compared to meat
– SFAs from cheese ↓LDL compared to butter
Which sat fats increase LDL?
– Lauric: may increase HDL-C more, thus ↓LDL/HDL ratio
– Myristic
– Palmitic: may ↑LDL-C only in presence of high dietary cholesterol
What is the effect of omega 6 on LDL and HDL levels?
increases LDL clearance
>10% may decrease HDL
What is the intake goals for omega 6?
5-10% of calories
What are the food sources of omega 6?
corn, sunflower, safflower, soybean oils, walnuts, sunflower seeds,…
How does w-6 lower LDL?
LDL lowering effect is partly passive – removes the suppressing effect of SFA (similar to oleic acid and carbohydrates)
High intakes of w-6 might cause ___
– Immune suppression
– Increased oxidative damage to LDL
– Increased cancer risk (with very high PUFA intake)
What are the intake goals for MUFAs?
Goal is no more than 20% of total calories – assuming a lower saturated fat intake
PUFA vs MUFA on HDL
Compared to PUFA, oleic acid does not lower HDL
MUFA vs SFA on LDL
Compared to saturated fats (C:12 – C:16) oleic acid lowers LDL
What are the food sources of MUFAs
olive and canola oils, peanuts, meat and poultry
What are the advantage of MUFAs
- mediterranean diet
– Do not decrease HDL as does PUFA and carbohydrates – Less susceptible to oxidation
– Do not increase triglycerides as carbohydrates often do – Do not increase cancer risk as high PUFA intakes could
What are omega-3 PUFAs
EPA: eicosapentanoic acid (fish)
DHA: docosahexanoic acid (fish)
ALA: Alpha-linolenic acid (canola, linseed, soybean oil)
How do w-3 affect TG levels?
- Decrease TG in hyperlipidemic and hyperTG patients
* May reduce mortality in those with CVD
How do w-3 affect VLDL levels?
Do not reduce the number of VLDL particles being secreted by the liver but rather decrease the TG content of these particles
How do w-3 affect LDL levels?
Omega-3 PUFAs do not lower LDL-C concentrations except as their PUFA replace SFA in the diet
How do w-3 prevent coronary thrombosis?
- Omega-3 PUFAs interfere with platelet aggregation and thereby prevent coronary thrombosis; retard proliferation of fibroblasts
- Reduce plaque formation and growth as they reduce adhesion molecules
How do trans fats affect LDL and HDL levels?
- Increase LDL-C, similar to saturated fats, but reduce LDL size (more atherogenic)
- Reduce HDL-C
- May ↑inflammatory markers and endothelial damage
How do trans fats occur?
Occur as a result of partial hydrogenation.
What are the food sources of trans fats?
hard margarines, partially hydrogenated oils used in many foods, small amounts in dairy (which may not have the same effects)
What are the intake goals of dietary fiber?
Goal is 20-30 g/day; about 50% of which should be soluble
How does dietary fiber affect total cholesterol and LDL?
Soluble fibers decrease Total-C and LDL-C – may be dependent on initial level of hypercholestorolemia