part 2 of 2
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RMR
I would also like to ask you a question about lipoprotein (a). How important
a risk factor for coronary artery disease is Lp(a) in 1997?
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AHL
There is good evidence to suggest that Lp(a) levels do correlate positively
with risk of developing cardiovascular disease. I think there is also
evidence to suggest, except for small differences, that Lp(a) levels are
determined by genetics, and not as much by diet or lifestyle. Now there are
some reports, for example, that trans fatty acids may increase Lp(a) levels.
However, the extent to which they have been reported to increase the levels
is relatively small in relation to the types of differences one sees either
within a population or among populations that actually impact on risk of
developing cardiovascular disease. At some point, Lp(a) levels may actually
be used as yet another risk factor to determine how aggressively one needs
to be treated to reduce CHD risk, but at this point, it is not considered to
be an independent risk factor. However, I think we should reassess the
situation in two or three years from now.
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RMR
Finally, I would like you to summarize what a doctor should tell his or her
patient whose blood test comes back showing a cholesterol level of say 250
and, secondly, what one tells a patient whose triglyceride levels come back
at 210 (quite above the normal range)?
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AHL
Let's first take the situation with someone who has a total cholesterol of
250 mg/dl, hence at first glance is in the high-cholesterol range (Table 1).
If HDL cholesterol level is available, the information in Table 4 can be
used to assess the best course of primarily prevention for this individual.
If the HDL cholesterol levels are below 35 mg/dl or the individual has two
or more risk factors, they should have a lipoprotein profile determined.
This blood sample must be collected after a 12 hour fast so that an accurate
fasting triglyceride level can be determined. This is particularly important
because LDL cholesterol levels, in standard clinical laboratories, are
estimated from total cholesterol, HDL cholesterol and VLDL cholesterol
levels (which themselves are estimated by dividing the triglyceride level by
five).
Once the LDL cholesterol level is available, the information in Table 5 can
be used to further assess the best course of primary prevention. For a
summary of LDL levels and number of risk factors to initiate therapy on the
basis of whether an individual had CHD or not refer to Table 6. Also
included are LDL goals so that the effectiveness of treatment can be
assessed.
For a patient with a triglyceride level of 210 mg/dl, the first thing to do
would be to repeat the determination, making certain the patient is fasting
and LDL and HDL cholesterol levels are determined. From there, proceed as
for a person with an elevated total cholesterol level to determine the best
course of treatment. If a person has only elevated triglyceride levels,
issues related to excess alcohol consumption should be explored. Frequently,
limiting consumption of simple carbohydrate (sugar) and alcohol is helpful
in bringing down high triglyceride levels.
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Often A 15% Reduction in Cholesterol Levels By Diet Alone
RMR
Three brief last questions, Alice. How much of a change in cholesterol can
one expect by diet alone? What is the practical experience when a physician
is managing these patients? When does he or she decide to go from diet to
medication for cholesterol lowering purposes?
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AHL
>From diet alone, we can expect a 5% to 15% decrease in blood cholesterol
levels. If someone is responding on the low side, it is important to
determine whether this low response is due to poor adherence to the dietary
recommendation (see CyberoundsTM Psychiatry/Neuroscience), a
misunderstanding of what the dietary recommendations are, overall
non-compliance with the recommendations or if the person is simply a
non-responder to dietary intervention. Obviously, it is not easy to sort out
reasons for low response. However, our work has clearly shown that in
individuals provided with all their food and drink, and that we were
reasonably certain were compliant, we observe, on average, a 15% decrease in
blood cholesterol.
What is the practical experience for a physician who is managing the
patients? Talk to the patient. Get a good assessment of how invested they
are in altering their diet and lifestyle (exercise habits). Assess whether
they have a good grasp of the dietary material presented to them. If it
appears they are serious about trying to lower their blood cholesterol with
diet, provide adequate support to accomplish this--for example, written
materials such as those available from the American Heart Association, or
referral to a registered dietitian or nurse specifically trained in helping
individuals comply with dietary recommendations.
When does the physician decide to go from diet to medication for cholesterol
lowering purposes? Table 6 specifies on the basis of LDL cholesterol levels
when it is appropriate to initiate drug therapy. I think it is reasonable to
give people a three-month period to alter their diet. As indicated before,
provide the support system that may be necessary to individuals on the basis
of their eating habits and lifestyle.
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The Truth About Olive Oil
RMR
My final question is about olive oil. This has certainly been in fashion
lately, both in restaurants and in the media, and is almost being promoted
as a health food. Does olive oil have some particular advantages over
unsaturated fats that we should be emphasizing it to such a degree as
indicated in magazines we read?
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AHL
Olive oil is classified as a vegetable oil as are many other oils. Most
vegetable oils, except for the tropical oils (Table 7), are relatively high
in unsaturated fatty acids. There are two subclassifications for unsaturated
fatty acids, monounsaturated and polyunsaturated. Examples of oils that are
relatively high in monounsaturated fatty acids include olive oil and canola
oil. Examples of oils that are relatively high in polyunsaturated fatty
acids are corn, soy bean and sun flower seed oils.
Substituting vegetable oils for animals fats will reduce the saturated fat
intake and result in lower blood cholesterol levels. Is olive oil
particularly special relative to other vegetable oils? Probably not. It is
high in monounsaturated fatty acids, but cannola oil is also high in
monounsaturated fatty acids. Do I think it is a good oil? Yes. Is it as good
as any of the other vegetable oils, especially vegetable oils high in
monounsaturated fatty acids? Is it better? The jury's still out. It's
certainly not magical. One danger is the misconception that, if a little bit
is good, then a lot is better, which is not what anyone is trying to imply.
Certainly, it is better to use olive oil than to use saturated fat. However,
it is also important to remember that, for some people, with respect to
total energy balance and fat intake, it is important to be moderate in one's
consumption of all types of fat.
So is pouring olive oil over a hot fudge sundae going to make it better for
you? Unlikely."

Tables
Table 1: Classification on the Basis of Total Cholesterol Levels
< 200 mg/dl  (< 5.2 mmol/L) Desirable cholesterol
201-239 mg/dl  (5.2-6.2 mmol/L) Borderline-high cholesterol
> 240 mg/dl  (> 6.2 mmol/L) High cholesterol
return
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Table 2: Positive and Negative Risk Factors
Positive Risk Factors
Age
Male > 45 years
Female > 55 years or premature menopause without estrogen replacement
therapy
Family History of Premature CHD
Myocardial infarction or sudden death before 55 years or 65 years of age in
parent or first-degree relative, male female, respectively
Current Cigarette Smoking
Hypertension
Blood pressure > 140/90 mm Hg (should be confirmed) or taking
antihypertensive medication
Low high density lipoprotein (HDL) cholesterol (<35 mg/dl [0.9 mmol/L])
Diabetes mellitus

Negative Risk Factor
(subtract one positive risk factor)

High HDL cholesterol (> 60 mg/dl [1.6 mmol/L])
return
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Table 3: Recommended Diets to Reduce Risk and/or Blood Cholesterol Levels
Dietary Factor
Step 1
Step 2
Total Fat
< 30% energy
< 30% energy
Saturated Fat
8-10% energy
< 7% energy
Cholesterol
< 300 mg/day
< 200 mg/day
Carbohydrate
> 55% energy
> 55% energy
Protein
15% energy
15% energy

return
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Table 4: Primary Prevention Without Evidence of Coronary Heart Disease
Desirable Blood Cholesterol (< 200 mg/dl [< 5.2 mmol/L])
HDL cholesterol > 35 mg/dl
Provide education on Step 1 diet, physical activity and risk factor
reduction
Repeat total and HDL cholesterol within 5 years
HDL cholesterol < 35 mg/dl
Lipoprotein analysis to determine LDL cholesterol (see Table 5)

Borderline-High Blood Cholesterol (201-239 mg/dl [5.2-6.2 mmol/L])
HDL cholesterol > 35 mg/dl and fewer than 2 risk factors
Provide education on Step 1 diet, physical activity and risk factor
reduction
Reevaluate patient 1 to 2 years (repeat total and HDL cholesterol measures)
Reinforce nutrition and physical activity education
HDL cholesterol < 35 mg/dl or 2 or more risk factors
Lipoprotein analysis to determine LDL cholesterol (see Table 5)

High-Blood Cholesterol (>240 mg/dl [>6.2 mmol/L])

Lipoprotein analysis to determine LDL cholesterol (see Table 5)
return
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Table 5: Classification on Basis of Low Density Lipoprotein (LDL)
Cholesterol -- Primary Prevention in Adults <I>Without</I> Evidence of
Coronary Heart Disease
Lipoprotein analysis after fasting 9-12 hours:
Desirable LDL Cholesterol (< 130 mg/dl [3.4 mmol/L])

Provide education on Step 1 diet, physical activity and risk factor
reduction
Repeat total and HDL cholesterol wiithin 5 years

Borderline-High Risk LDL Cholesterol (130 to 159 mg/dl [3.4 to 4/1 mmol/L])
fewer than two risk factors
Provide education on Step 1 diet and physical activity
Reevaluate patient status annually, repeat lipoprotein analysis, reinforce
nutrition and physical activity education
2 or more risk factors
Do clinical evaluation (history, physical examination and laboratory tests)
Evaluate secondary causes and familial disorders (when indicated)
Initiate Step 1 diet, if inadequate response achieved, initiate Step 2 diet

High Risk LDL Cholesterol (>160 mg/dl [4.1 mmol/L])

Do clinical evaluation (history, physical examination and laboratory tests)
Evaluate secondary causes and familial disorders (when indicated)
Initiate Step 1 diet, if inadequate response achieved, initiate Step 2 diet
return
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Table 6: Treatment Based on LDL Cholesterol Levels
Therapy type
LDL level at which to initiate therapy LDL Goal
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Diet Therapy

Without CHD and fewer than 2 risk factors
> 160 mg/dl
< 160 mg/dl
Without CHD and 2 or more risk factors
> 130 mg/dl
< 130 mg/dl
With CHD
> 100 mg/dl
< 100 mg/dl

Drug Therapy

Without CHD and fewer than 2 risk factors
> 190 mg/dl
< 160 mg/dl
Without CHD and 2 or more risk factors
> 160 mg/dl
< 130 mg/dl
With CHD
> 130 mg/dl
< 100 mg/dl
return
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Table 7: Foods Relatively High in Saturated Fat
Animal fats
Full fat dairy products (butter, whole fat milk, cheese, ice cream)
Meat (beef, pork, poultry with skin)
Plant Oils
coconut oil
palm oil
palm kernel oil
cocoa butter
return
References
Mensink RP, Katan MB. Effect of dietary trans fatty acids on high-density
and low-density lipoprotein cholesterol levels in healthy subjects. N Engl J
Med 1990;323:439-445 return
Lichtenstein AH, Ausman LM, Carrasco W, Jenner JL, Ordovas JM, Schaefer EJ.
Hydrogenation impairs the hypolipidemic effect of corn oil in humans.
Arteriosclerosis and Thrombosis 1993;13:154-161. return
Judd JT, Clevidence BA, Muesing RA, Wittes J, Sunkin ME, Podczasy JJ.
Dietary trans fatty acids: effects on plasma lipids and lipoproteins of
healthy men and women. Am J Clin Nutr 1994;59:861-868 return
ASCNI/AIN Task Force on Trans Fatty Acids. Feldman EB, Kris-Etherton PM,
Kritchevsky D, Lichtenstein AH. Position paper on trans fatty acids. Am. J.
Clin. Nutr. 1996;63:663-670 return
created 7/2/97; reviewed 7/15/97; modified 8/8/97