Dyslipidemia and CVD Part 2 Flashcards
1
Q
What are the benefits of weight loss of 2-7kg in terms of blood lipid profile?
A
- 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
2
Q
What are the benefits of physical activity in terms of blood lipids?
A
- 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
3
Q
What are the predictive equations of effects on diet on serum total cholesterol?
A
KEYS
HEGSTED
4
Q
What are the limitations of Predictive Equations?
A
- 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
5
Q
What is the 7 countries study?
A
- east Finland had the highest coronary deaths
- Ushibuka has the lowest coronary deaths
- Focus was Crete - mediterranean diet!!
6
Q
What is dietary cholesterol and what is its impact on blood cholesterol levels?
A
- 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
7
Q
What are the independent mechanisms of dietary cholesterol?
A
– 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
8
Q
Saturated fats reduce the activity of LDL receptors by?
A
– Decreasing transcription of LDL receptor gene
– Altering PL composition of cell membranes to decrease binding
– Altering LDL itself and delays binding to receptors
9
Q
What are the major sat. fat sources in the diet?
A
baked goods and processed foods
10
Q
What are medium chain sat fats?
A
caprylic (8)
caproic (10)
11
Q
What are intermediate chain sat fats?
A
lauric (12)
12
Q
What are long chain sat fats?
A
myristic (14)
palmitic (16)
stearic (18)
13
Q
How do sat fats affect blood LDL levels?
A
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
14
Q
Which sat fats increase LDL?
A
– Lauric: may increase HDL-C more, thus ↓LDL/HDL ratio
– Myristic
– Palmitic: may ↑LDL-C only in presence of high dietary cholesterol
15
Q
What is the effect of omega 6 on LDL and HDL levels?
A
increases LDL clearance
>10% may decrease HDL
16
Q
What is the intake goals for omega 6?
A
5-10% of calories
17
Q
What are the food sources of omega 6?
A
corn, sunflower, safflower, soybean oils, walnuts, sunflower seeds,…
18
Q
How does w-6 lower LDL?
A
LDL lowering effect is partly passive – removes the suppressing effect of SFA (similar to oleic acid and carbohydrates)
19
Q
High intakes of w-6 might cause ___
A
– Immune suppression
– Increased oxidative damage to LDL
– Increased cancer risk (with very high PUFA intake)
20
Q
What are the intake goals for MUFAs?
A
Goal is no more than 20% of total calories – assuming a lower saturated fat intake
21
Q
PUFA vs MUFA on HDL
A
Compared to PUFA, oleic acid does not lower HDL
22
Q
MUFA vs SFA on LDL
A
Compared to saturated fats (C:12 – C:16) oleic acid lowers LDL
23
Q
What are the food sources of MUFAs
A
olive and canola oils, peanuts, meat and poultry
24
Q
What are the advantage of MUFAs
A
- 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
25
What are omega-3 PUFAs
EPA: eicosapentanoic acid (fish)
DHA: docosahexanoic acid (fish)
ALA: Alpha-linolenic acid (canola, linseed, soybean oil)
26
How do w-3 affect TG levels?
* Decrease TG in hyperlipidemic and hyperTG patients
| * May reduce mortality in those with CVD
27
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
28
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
29
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
30
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
31
How do trans fats occur?
Occur as a result of partial hydrogenation.
32
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)
33
What are the intake goals of dietary fiber?
Goal is 20-30 g/day; about 50% of which should be soluble
34
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
35
How does CHO affect HDL and LDL?
Decreases HDL formation and/or Apo-AI synthesis
Overproduction of VLDL-TG especially if sucrose, fructose, or high-fructose corn syrup
36
What are the disadvantages of high CHO diet?
– Decreased HDL and increased TG
– Hyper TG in some populations
– Could increase blood glucose and hyperinsulinemia
37
What are the benefits of red wine on blood lipid profile?
Elevate HDL-C
Red wine in particular may inhibit cell-mediated oxidation of lipoproteins – due to resveratrol (polyphenol) NOT alcohol – FRENCH PARADOX
38
How does soy protein affect total cholesterol, TG and LDL?
* Reduces T-C, LDL-C, and TG without an effect on HDL-C in patients with or without CVD
* Due to isoflavones and phytoestrogens
39
How do antioxidants affect the lipid profile?
May inhibit LDL oxidation thereby decreasing atherosclerosis risk – oxidized fat less capable of being removed
40
What are the normal fasting concentrations of folate and B6?
* Normal fasting concentrations: 6-12 umol/L
| * If >14 umol/L à increased risk of heart disease
41
What is the relationship between homocysteinemia, folate and B6?
Low levels of folate especially are associated with high homocysteine levels
42
What are the recommendations for supplementation for homocysteinemia?
• Supplement only in persons with high levels or family history of
CVD: 500 μg folate/day (once B12 deficiency is ruled out )
• Low levels of B12 not associated with increased risk of CHD
43
What are the food sources of folate?
fortified cereals, vegetables, citrus fruits/juices, legumes, organ meats
44
What are phytosterols and where are they found?
* Equivalent to plant cholesterol
* Compete with cholesterol absorption: increase fecal excretion
* Diet enriched with 2-2.5 g sterols/stanols reduced LDL-C by 6- 14%
* This amount almost impossible to obtain from normal foods: fortified margarines are the main source
45
What are the benefits of nuts?
• Rich in mono- and polyunsaturated FA, most low in SFA
• High in plant protein, soluble fibers, folic acid, antioxidants,
arginine (NO precursor)
46
How do nuts affect lipid profile?
```
High intake (30-60 g/d) reduces risk of CHD, moderate intake
reduces LDL-C and improves endothelial function
```
47
What is the Dietary approach for dyslipidemia?
• Based on global cardiovascular risk (Framingham)
• 1st target: LDL-C, then factors of the metabolic syndrome
• TLC model = therapeutic lifestyle changes
- saturated fats and dietary cholesterol
Step I: <10% SFA and <300 mg cholesterol
Steps II and III: <7% SFA and <200 mg cholesterol
- physical activity
- weight management to reduce coronary risk
48
What is the mediterranean diet?
– high in oleic acid (olive oil)
– high in fruits, vegetables, legumes
– high in fish, low red meat, moderate dairy (mostly cheese and yogurt)
– regular but moderate wine consumption
49
What are the benefits of mediterranean diet?
– Primary prevention:
• PREDIMED trial: 30% ↓ in CV events, favorable lipid
profile compared to low fat diet: ↓ LDL-C, apo-B and
TG, ↑HDL-C
• Other studies: additive effects to statins, ↓
inflammatory markers, favors weight loss, 25%
↓mortality
– Secondary prevention: Lyon Study: 70% ↓mortality post-MI
50
What is the portfolio diet?
– low in saturated fats
| – high in phytosterols (1 g, margarine), soy protein (21 g), soluble fibers (10 g), almonds (14 g) (all/1000 kcal)
51
What are the benefits of the portfolio diet?
– ↓ 29% in LDL-C vs. 31% with low-fat diet +statins vs. 8% low-fat diet, ↓CRP vs. low-fat diet, under controlled conditions
– In a clinical study: ↓13% in LDL-C in portfolio intensive vs. 13% in portfolio routine vs. 3% in diet low in SFA. 11% ↓ in FRS.
– But adherence to portfolio diet is low: about 40-45%
52
What are the dietary goals for extremely high triglycerides (>11.00 mmol/L), major risk from pancreatitis (this is rare so
no pre-calculated diet is provided) e.g., Type I HLP?
1. Attain or maintain ideal body weight
2. 10-15% energy from fat (20-30 g/day)
3. MCT oil may be used to provide extra energy 4. No alcohol
53
What are the dietary goals for Blood cholesterol 3 75th percentile, e.g., Type IIa and IIb HLP?
1. Attain or maintain ideal body weight
2. Decrease total fat intake, primarily saturated fat with a partial substitution of polyunsaturated fat
3. Decrease cholesterol intake
54
What are the dietary goals for blood triglycerides 3 90th percentile, e.g., commonly elevated in uncontrollable diabetes, alcohol excess, Type IV and V HLPs
1. Attain or maintain ideal body weight
2. Decrease or eliminate alcohol
3. Decrease or eliminate sugar
4. Decrease total fat with modest addition of
polyunsaturated fat
55
What are the dietary goals for Severe type V HLP = triglycerides 3 11.00 mmol/L
Decrease total fat to 20% of total energy and eliminate alcohol
56
What are the dietary goals for Combination - elevated blood cholesterol and triglyceride, e.g., obesity, diabetes, Type IV and Type III HLPs
1. Attain or maintain ideal body weight
2. Decrease total fat intake, primarily saturated fat with a partial substitution of polyunsaturated fat
3. Decrease cholesterol intake
4. Decrease or eliminate alcohol and/or added sugar
57
What are the classes of drugs for treatment of hyperlipidemia?
- HMG-CoA reductase inhibitors (statins)
- Cholesterol absorption inhibitors
- Bile acid sequestrants (BAS)
- PCSK9 inhibitors
58
What are the names of HMG-CoA reductase inhibitors
| (statins)?
```
atorvastatin (LipitorTM)
lovastatin (MevacorTM)
simvastatin (ZocorTM)
rosuvastatin (CrestorTM)
pravastatin (PravacholTM)
```
59
What are the names of Cholesterol absorption inhibitors?
ezetimibe (EzetrolTM)
60
What are the names of Bile acid sequestrants (BAS)?
cholestyramine (QuestranTM)
| colestipol (ColestidTM)
61
What are the names of PCSK9 inhibitors?
evolocumab (RepathaTM)
| alirocumab (PraluenTM)
62
What are the predicted effects of statins?
decreased LDL-C (18-55%)
decreased TG (17-30%)
increased HDL-C (5-15%)
63
What are the predicted effects of Cholesterol absorption inhibitors?
decreased LDL-C (18% mono, 25% with statin)
64
What are the predicted effects of Bile acid sequestrants (BAS)?
decreased LDL (15-30%)
65
What are the predicted effects of PCSK9 inhibitors?
decreased LDL (about 50%)*
66
What is the mechanism of statins?
- Block cholesterol synthesis
| - increases LDL receptor mediated removal
67
What is the mechanism of Cholesterol absorption inhibitors?
Inhibit cholesterol GI absorption
68
What is the mechanism of Bile acid sequestrants (BAS)?
Promote sterol excretion
| increases LDL receptors
69
What is the mechanism of PCSK9 inhibitors?
Prevent catabolism of LDL receptors
– enzyme that binds to LDL receptors and promote their degradation (instead of LDL recycling on the cell surface)
– Inhibitors are monoclonal antibodies that block PCSK9 action --> more LDL recycling
70
What are the names of fibrates?
gemfibrozil (LopidTM)
| fenofibrate (LipidilTM)
71
What are the names of nicotinic acid?
nicotinic acid slow release (QuestTM, NiaspanTM)
72
What are the predicted effects of fibrates?
decreased TG (20-50%)
increased HDL-C (15-35%)
decreased LDL-C (5-25%)
73
What are the predicted effects of nicotinic acid?
decreased TG (20-50%)
increased HDL-C (15-35%)
decreased LDL-C (5-25%)
74
What is the mechanism of fibrates?
Decreases VLDL synthesis, enhances LPL action
75
What is the mechanism of nicotinic acid?
Decreases VLDL synthesis, increase LPL activity
76
What are the adverse effects and interactions of statin?
myalgia and myopathy, increased liver enzymes and low risk of diabetes (liver enzymes should be monitored semi- annually)
interaction with grapefruit juice
77
When is ezetimibe recommended?
Recommended as second-line Tx in patients with clinical CVD and targets not reached by maximal statin dose
78
What are the adverse effects and interactions of ezetimibe?
* Possible side effects: diarrhea, rash, fatigue, muscle weakness or pain
* Contra-indications: liver disease or failure
79
What are the adverse effects and interactions of BAS?
* May decrease absorption of fat and liposoluble vitamins, Ca, Fe, Zn, Mg
* Side effects: significant constipation
* Contraindications: existing hemorrhoids, peptic ulcer, hiatus hernia, multiple drug use, extensive travel, hypertriglyceridemia
80
When is PCSK9 recommended?
Recommended for primary (familial) hypercholesterolemia with high LDL-C despite maximal statin dose
81
What are the adverse effects and interactions of PCSK9?
diarrhea, muscle or joint pain, bruising around injection site
82
What are the recommendations for treatment of TG?
* No specific target level for high-risk
* Lower triglyceride levels are associated with decreased CVD risk
* Health behavior interventions are first-line
* Fibrates may prevent pancreatitis in patients with extreme hypertriglyceridemia (>10 mmol/L)
83
What are the recommendations for treatment of HDL?
* Low HDL-C may pose no risk, depending on genetic type
* Medications may not increase HDL-C to a clinically significant extent
* Health behaviour interventions increase HDL-C
84
When should fibrates be used?
* For use in highly elevated TG (familial hyperTG)
| * Not recommended to add to statin for CVD prevention when target has been reached
85
What are the adverse effects and interactions of fibrates?
* Side effects: GI reactions (taste changes, abdominal pain), muscle toxicity
* May cause reversible increases in plasma creatinine
* Contraindications: hepatic or renal dysfunction, gallbladder disease, combination Tx with simvastatin
86
When should nicotinic acid be used?
* Used for primary hypercholesterolemia and/or hypertriglyceridemia, and hypoalphalipoproteinemia
* Not recommended as add-on to statins
87
What are the adverse effects and interactions of nicotinic acid?
* Side effects: only 50-60% tolerate nicotinic acid: GI distress, skin flushing and itching, hepatotoxicity, arrhythmias
* Monitor uric acid levels
* Contraindications: active peptic ulcer, hepatic disease, gout, hyperuricemia
