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Diet Therapy and Coronary Heart Disease (CHD) I. Risk Factors for Developing CHD. II. Diet-Responsive Risk Factors for CHD. A. American Heart Association 'Step' Diets ... – PowerPoint PPT presentation

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Title: HNF 470


1
HNF 470 Diet Therapy and
Coronary Heart Disease (CHD) I. Risk Factors for
Developing CHD II. Diet-Responsive Risk Factors
for CHD A. American Heart Association Step
Diets B. Role for Dietary Supplements? III. Diet
Therapy in the Secondary Prevention of
IHD IV. Diet Therapy in the Primary Prevention
of IHD V. Are AHA Step I and II Guidelines
Enough? http//www.msu.edu/cour
se/hnf/470
2
The Cardiovascular Diseases
Hypertension
Myocardial Infarction
Atherosclerosis
Congestive Heart Failure
Definitions and Terminologies
Stroke (CVA)
3
The Burden Deaths due to CVD are the 1
cause of death in the u.s. (1 Coronary
heart Disease 3 Stroke) Mortality has
dropped DRAMATICALLY in the past two
decades-- 1 ly due to advances in
treatment Incidence has not changed.
4
Coronary Heart
Disease Cause Formation of Atherosclerotic
Plaques Risk Factors Maleness (gt45 yo),
Femaleness (gt55 yo) High LDL (gt160 mg/dl) Low
HDL (lt35 mg/dl) Hypertension (Diastolic gt90 mm
Hg) Smoker DM Family Hx Etiology Current
hypothesis Oxidation of the apolipoprotein com
ponent of LDL leads to injury of cells
lining the artery (intima). Damage leads to
platelet activation, excessive clotting, and
atherogenesis. Narrowing of the artery leads to
a hypoxic (ischemic) condition in target organs.
5
Risk Factors for CHD The Framingham Heart Study
Major Risk Factors Important Risk
Factors Cigarette Smoking Obesity Hypertension
Physical Inactivity High Total Serum
Cholesterol Family Hx of Premature CHD Low HDL
Cholesterol Hypertriglyceridemia Diabetes
Mellitus Increased Lipoprotein
a Increased serum homocysteine Abnorm
al levels of various coagulation
factors Dietary factors contribute strongly to
the control of or in the etiology of these risk
factors.
6
Diet-Related Risk
Factors High LDL Cholesterol Begin
treatment LDL Cholesterol
(mg/dl) With CHD
gt100 Without CHD one risk factor
gt160 Without CHD gt 2 risk factors
gt130 Low HDL Cholesterol Hypertension Di
abetes Mellitus
7
CVD Risk Factor Standards
Blood Lipid Fraction Desirable Borderline
High LDL Cholesterol (mg/dl) lt130
130-159 gt160 Total Cholesterol (mg/dl)
lt200 200-239 gt240 Triglycerides
(Fasting mg/dl) lt200 200-400
gt400 HDL Cholesterol Low (Bad) if 35
mg/dl LDLHDL ratio gt 5 indicates risk for
men gt4.5 indicates risk for women
8
Standard for Blood Pressure
Diastolic Pressure (mm Hg) lt 85 Normal 80-89
High-Normal 90-99 Mild 100-109
Moderate 110-119 Severe gt120 Very Severe
9
Figure 1 Annual trends in incidence and case
fatality rate of CHD by country.
United States Russia, E. Europe, China

Source http//www.bmj.com
10
Source http//www.bmj.com
11
Role of Diet in the Modification of Blood
Cholesterol Levels Assumptions Blood
cholesterol is an important and modifiable
risk factor for coronary heart disease.
Sustained reduction of total cholesterol of
1 is associated with a 2-3 reduction in the
incidence of coronary heart disease.
12
Total Cholesterol Levels (mg/dl) in the
U.S. (National Health and Nutrition Examination
Surveys)
Age Group 1976-80 1988-1994 Adults
213 203 Adolescents (ages 12-17)
167 160
13
Role of Diet in the Modification of Blood
Cholesterol Levels-3
Efficacy of Dietary Intervention Trials to Lower
Total Cholesterol
Diet Types Reduction in Total
Cholesterol AHA Step 2 Lower Total Fat
6.0 Raise PUFASFA Ratio AHA Step
1 3.0
Tang et al. (1998) BMJ 316 1213-1220 Systematic
review of dietary intervention trials to lower
blood total cholesterol in free-living subjects.
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15
Role of Diet in the Modification of Blood
Cholesterol Levels-4
How Do These Results Compare to Metabolic Ward
Studies? Dietary change results in decreases
of total cholesterol up to 15. Difficulties
in complying with the prescribed dietary
change may explain the failure to achieve the
expected reductions in cholesterol
concentrations. Even so, diets low in
saturated fat and cholesterol are important
adjunctive therapies for lowering
population risk of CHD.
Tang et al. (1998) BMJ 316 1213-1220 Systematic
review of dietary intervention trials to lower
blood total cholesterol in free-living subjects.
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Role of Diet in the Modification of Blood
Cholesterol Levels-2
Chief Determinants of Blood Cholesterol
Levels 1. Certain saturated fatty acids cause a
linear increase in low-density lipoprotein (LDL)
cholesterol concentration. (Total SFA in U.S.
Diet 11-12 of total energy) 2. Trans
unsaturated fatty acids increase LDL
cholesterol not quite as atherogenic as
certain SFA. (Total trans FA in U.S. Diet 3
of total energy) 3. Polyunsaturated fatty acids
derived from plant oils do NOT raise LDL
cholesterol . (Total PUFA in U.S. Diet 6
of total energy) 4. Monounsaturated fatty acids
derived from high oleic acid (cis-181) oils
(e.g., olive, peanut, canola) do NOT raise LDL
cholesterol .
18
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Deciles of PUFASFA Ratio and Risk of CHD in
Women (Hu et al. AJCN 70
1001-8, 1999)
20
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21
The eating plan is based on these AHA
dietary guidelines Total fat intake should
be less than 30 of calories.
Saturated fatty acid intake should be less
than 10 of calories.
Polyunsaturated fatty acid intake should be
no more than 10 percent of calories.
Monounsaturated fatty acids make
up the rest of the total fat intake, about 10
to 15 of total calories.
Cholesterol intake should be no more than
300 mG per day. Sodium
intake should be no more than 2400 milligrams
(3 grams) per day.
22
Fruit and Vegetable Intake in the Nurses Health
Study and Relative Risk of CHD
23
To control the amount and kind of
fat, saturated fatty acids, and dietary
cholesterol you eat Eat up to 6
ounces (cooked) per day of lean meat, fish and
skinless poultry.
The approximately 5 to 8 teaspoon servings
of fats and oils per day may be used for
cooking and baking, and in salad dressings
and spreads. Use cooking
methods that require little or no fat boil,
broil, bake, roast, poach, steam,
sauté, stir-fry or microwave.
Trim off the fat you can see before cooking
meat and poultry. Drain off all fat after
browning. The 3 to 4 egg yolks per week
included in your eating plan may be used alone or
in cooking and baking (including
store-bought products).
Choose skim or 1 fat milk and nonfat
or low-fat yogurt and cheeses.
24
Physicians Health StudyHennekens et al. (1996) N
Engl J Med 3341145.
22,071 male physicians randomized to
alternate-day ß-carotene (50 mg), aspirin (325
mg), both active treatments, or both
placebos. Aspirin component terminated early
(1988) due to statistically extreme 44
reduction in risk of first myocardial
infarction. After 12 years of treatment with
ßC, there was no effect on any CA endpoint, MI,
stroke, or CHD deaths.
25
Vitamin E Supplementation and CHD
Evidence from prospective trials (Physicians
Health Study, Nurses Health Study) showed 40
reduction in CHD incidence with gt 2 yrs intake
of gt100 I.U. AT. The Iowa Womens Health Study
showed that vitamin E content in FOOD, not
supplements, was inversely associated with risk
of death from CHD (lowest vs. highest quintile
of consumption RR 0.38p0.004)
26
Cambridge Heart Antioxidant Study
(Stephens et al. (1996) Lancet 347 781-86)
Double-blinded study of the prevention of CVD
death and non-fatal MI in patients with
angiographically proven coronary
atherosclerosis receiving alpha tocopherol or a
placebo. 2002 patients
546 (800 I.U.) 489 (400
I.U.) 967 (placebo) Median
follow-up 510 days (range 3-981)
27
CHAOS Results
1. Alpha tocopherol treatment decreased risk of
CVD death and non-fatal MI Relative Risk
(RR) 0.53 (95 CI 0.34-0.83 p0.005) 2. Most
of this benefit was due to decreased risk of
non-fatal MI RR 0.23 (95 CI 0.11-0.47
p0.005) 3. Non-significant INCREASE or excess
in cardiovascular deaths in the treatment group
compared to the placebo group.
28
Vitamin E A Review
Function Cell Membrane Antioxidant (prevents
lipid peroxidation/free radical generation)
Alpha-Tocopherol Gamma-Tocopherol higher
vitamin E activity principal form of
more potent antioxidant vitamin E in
U.S. diet primary form of supplemental vitamin
E more rapid uptake and low plasma levels
are strong predictors of cellular turnover
risk of certain cancers and CHD traps
mutagenic displaces gamma-T in plasma/other
tissues electrophiles like NOx 5-fold
higher plasma levels than gamma-T
29
Dietary Effectors of Endothelial Cell
Function (NOT ready for
prime time) Arginine substrate for
endothelial nitric oxide synthase HeartBar
3 grams arginine per bar Purports Heart
Healthy benefits Pharmacologic Doses of
Vitamins A and C Negative Effector High Fat
Diets
30
Frequent nut consumption and risk ofcoronary
heart disease in women prospective cohort study
Frank B Hu et al. Harvard University School of
Public Health BMJ 19983171341-1345 ( 14
November )
31
After adjusting for age, smoking, and other
known risk factors for CHD Women consuming gt
five ounces of nuts a week (frequent
consumption) vs. women who never ate nuts or
who ate lt one ounce a month (rare consumption)
had a significantly lower risk of total
coronary heart disease (RR 0.65, 95
confidence interval 0.47 to 0.89, P for
trend0.0009).
32
The magnitude of risk reduction was similar for
both fatal coronary heart disease (0.61, 0.35
to 1.05, P for trend0.007) non-fatal MI
(0.68, 0.47 to1.00, P for trend0.04). Further
adjustment for intakes of dietary fats, fibre,
vegetables, and fruits did not alter these
results. The inverse association persisted in
subgroups stratified by levels of smoking, use
of alcohol, use of multivitamin and vitamin E
supplements, body mass index, exercise, and
intake of vegetables or fruits.
33
Key messages Nuts are high in fat,
but most of the fatty acids are unsaturated
This study suggests that frequent
consumption of nuts, including peanuts, may
reduce the risk of coronary heart disease
This protective effect may be partly
mediated through serum lipids because
unsaturated fats have benefical effects on
serum lipids. Other potentially protective
constituents include vegetable protein,
magnesium, vitamin E, fibre, and potassium
Nuts can be included as part of a healthy
diet
34
Lyon Diet Heart Study(de Lorgeril et al., Arch
Int Med 158 1181-1187)
  • Randomized secondary prevention trial
  • 605 patients with coronary artery disease
    randomized to either a Meditarranean-type diet or
    control (A.H.A. Step 1-like) diet
  • After 4 years of follow-up, Cox proportional
    hazards model was used to estimate risk ratios
    for cancer, total or cardiac death, combined
    total death, nonfatal cancer, and nonfatal MI.

35
Table 1 Number of Events and Risk Ratios
de Lorgeril et al. (1998) Arch. Int. Med. 158
1181-1187.
36
Table 2 Characteristics of patients who
developed cancer in the two groups
37
Figure 1 Cumulative survival without nonfatal
cancer among patients in the experimental
and control groups.
38
Figure 2 Cumulative survival without nonfatal
cancer and recurrent acute MI among
patients in the experimental and control
groups.
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40
The Unified Dietary Guidelines
Eat a variety of foods. Choose most
foods from plant sources. Eat at
least 5 servings of fruits and vegetables every
day. Eat at least 6 servings of whole
grain foods each day. Minimize the
consumption of high-fat foods, especially
those from animals. Choose
low-fat, low-cholesterol foods. Limit
the amount of simple sugars in the diet.
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