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DIFINITIONA lipoprotein is a biochemical assembly that contains both proteins
and lipids water-bound to the proteins. Many enzymes, transporters,
structural proteins, antigens, adhesins, and toxins are lipoproteins.
Examples include the high-density (HDL) and low-density (LDL)
lipoproteins, which enable fats to be carried in the blood stream, the
transmembrane proteins of the mitochondrion and the chloroplast,
and bacterial lipoproteins.
Function
The function of lipoprotein particles is to transport lipids (fats) (such as
triacylglycerol) around the body in the blood.
All cells use and rely on fats and cholesterol as building-blocks to create the
multiple membranes that cells use both to control internal water content and
internal water-soluble elements and to organize their internal structure and
protein enzymatic systems.
The lipoprotein particles have hydrophilic groups of phospholipids, cholesterol,
and apoproteins directed outward. Such characteristics make them soluble in the
salt water-based blood pool. Triglyceride-fats and cholesterol esters are carried
internally, shielded from the water by the phospholipid monolayer and the
apoproteins.
The interaction of the proteins forming the surface of the particles (a) with
enzymes in the blood, (b) with each other, and (c) with specific proteins on the
surfaces of cells determine whether triglycerides and cholesterol will be added to
or removed from the lipoprotein transport particles.
Transmembrane lipoproteins
The lipids are often an essential part of the complex, even if they seem to have no
catalytic activity by themselves. To isolate transmembrane lipoproteins from their
associated membranes, detergents are often needed
Classification
[ By density
Lipoproteins may be classified as follows, listed from larger and less dense to
smaller and denser. Lipoproteins are larger and less dense, if they consist of more
fat than of protein. They are classified on the basis of electrophoresis and
ultracentrifugation.
Chylomicrons carry triglycerides (fat) from the intestines to the liver, to skeletal
muscle, and to adipose tissue.
Very-low-density lipoproteins (VLDL) carry (newly synthesised) triacylglycerol from
the liver to adipose tissue.
Intermediate-density lipoproteins (IDL) are intermediate between VLDL and LDL.
They are not usually detectable in the blood.
Low-density lipoproteins (LDL) carry cholesterol from the liver to cells of the body.
LDLs are sometimes referred to as the "bad cholesterol" lipoprotein.
High-density lipoproteins (HDL) collect cholesterol from the body's tissues, and
bring it back to the liver. HDLs are sometimes referred to as the "good cholesterol"
lipoprotein.
Density (g/mL)ClassDiameter (nm) % protein % cholesterol %
phospholipid % triacylglycerol
>1.063HDL5–153330294
1.019–1.063LDL18–282550218
1.006–1.019IDL25–5018292231
0.95–1.006VLDL30–8010221850
<0.95Chylomicrons100-1000>28784
[2]
Alpha and beta
It is also possible to classify lipoproteins as "alpha" and "beta", according to the
classification of proteins in serum protein electrophoresis. This terminology is
sometimes used in describing lipid disorders such as Abetalipoproteinemia.
Lipoprotein(a)
Lipoprotein(a) – Lp(a), Cardiology diagnostic tests
<14 mg/dL : Normal
14-19 mg/dL? :
>19 mg/dL : High risk].
What Is Atherosclerosis?
Atherosclerosis (ath-er-o-skler-O-sis) is a disease in which plaque (plak) builds up
inside your arteries. Arteries are blood vessels that carry oxygen-rich blood to your
heart and other parts of your body.
Plaque is made up of fat, cholesterol, calcium, and other substances found in the
blood. Over time, plaque hardens and narrows your arteries. This limits the flow of
oxygen-rich blood to your organs and other parts of your body.
Atherosclerosis can lead to serious problems, including heart attack, stroke, or
even death.
Atherosclerosis
Figure A shows a normal artery with normal blood flow. Figure B shows an artery
with plaque buildup.
Atherosclerosis-Related Diseases
Atherosclerosis can affect any artery in the body, including arteries in the heart,
brain, arms, legs, pelvis, and kidneys. As a result, different diseases may develop
based on which arteries are affected.
Coronary Heart Disease
Coronary heart disease (CHD), also called coronary artery disease, is the #1 killer of
both men and women in the United States. CHD occurs if plaque builds up in the
coronary arteries. These arteries supply oxygen-rich blood to your heart.
Plaque narrows the coronary arteries and reduces blood flow to your heart muscle.
Plaque buildup also makes it more likely that blood clots will form in your arteries.
Blood clots can partially or completely block blood flow.
If blood flow to your heart muscle is reduced or blocked, you may have angina
(chest pain or discomfort) or a heart attack.
Plaque also can form in the heart's smallest arteries. This disease is called coronary
microvascular disease (MVD). In coronary MVD, plaque doesn't cause blockages in
the arteries as it does in CHD.
Carotid Artery Disease
Carotid (ka-ROT-id) artery disease occurs if plaque builds up in the arteries on each
side of your neck (the carotid arteries). These arteries supply oxygen-rich blood to
your brain. If blood flow to your brain is reduced or blocked, you may have a
stroke.
Peripheral Arterial Disease
Peripheral arterial disease (P.A.D.) occurs if plaque builds up in the major arteries
that supply oxygen-rich blood to your legs, arms, and pelvis.
If blood flow to these parts of your body is reduced or blocked, you may have
numbness, pain, and, sometimes, dangerous infections.
Chronic Kidney Disease
Chronic kidney disease can occur if plaque builds up in the renal arteries. These
arteries supply oxygen-rich blood to your kidneys.
Over time, chronic kidney disease causes a slow loss of kidney function. The main
function of the kidneys is to remove waste and extra water from the body.
Overview
The cause of atherosclerosis isn't known. However, certain traits, conditions, or
habits may raise your risk for the disease. These conditions are known as risk
factors.
You can control some risk factors, such as lack of physical activity, smoking, and an
unhealthy diet. Others you can't control, such as age and a family history of heart
disease.
Some people who have atherosclerosis have no signs or symptoms. They may not
be diagnosed until after a heart attack or stroke.
The main treatment for atherosclerosis is lifestyle changes. You also may need
medicines and medical procedures. These treatments, along with ongoing medical
care, can help you live a healthier life.
Outlook
Improved treatments have reduced the number of deaths from atherosclerosis-
related diseases. These treatments also have improved the quality of life for
people who have these diseases. However, atherosclerosis remains a common
health problem.
You may be able to prevent or delay atherosclerosis and the diseases it can cause.
Making lifestyle changes and getting ongoing care can help you avoid the problems
of atherosclerosis and live a long, healthy life
TREATMENT OF atherosclerosis
Cholesterol medications. Aggressively lowering your low-density lipoprotein (LDL)
cholesterol, the "bad" cholesterol, can slow, stop or even reverse the buildup of
fatty deposits in your arteries. Boosting your high-density lipoprotein (HDL)
cholesterol, the "good" cholesterol, may help, too. Your doctor can choose from a
range of cholesterol medications, including drugs known as statins and fibrates.
Anti-platelet medications. Your doctor may prescribe anti-platelet medications,
such as aspirin, to reduce the likelihood that platelets will clump in narrowed
arteries, form a blood clot and cause further blockage.
Beta blocker medications. These medications are commonly used for coronary
artery disease. They lower your heart rate and blood pressure, reducing the
demand on your heart and often relieve symptoms of chest pain. Beta blockers
reduce the risk of heart attacks and heart rhythm problems.
Angiotensin-converting enzyme (ACE) inhibitors. These medications can help slow
the progression of atherosclerosis by lowering blood pressure and producing other
beneficial effects on the heart arteries. ACE inhibitors can also reduce the risk of
recurrent heart attacks.
Calcium channel blockers. These medications lower blood pressure and are
sometimes used to treat angina.
Water pills (diuretics). High blood pressure is a major risk factor for
atherosclerosis. Diuretics lower blood pressure.
Other medications. Your doctor may suggest certain medications to control specific
risk factors for atherosclerosis, such as diabetes. Sometimes specific medications
to treat symptoms of atherosclerosis, such as leg pain during exercise, are
prescribed.
Sometimes more aggressive treatment is needed. If you have severe symptoms or
a blockage that threatens muscle or skin tissue survival, you may be a candidate
for one of the following surgical procedures:
Angioplasty. In this procedure, your doctor inserts a long, thin tube (catheter) into
the blocked or narrowed part of your artery. A second catheter with a deflated
balloon on its tip is then passed through the catheter to the narrowed area. The
balloon is then inflated, compressing the deposits against your artery walls. A
mesh tube (stent) is usually left in the artery to help keep the artery open.
Endarterectomy. In some cases, fatty deposits must be surgically removed from the
walls of a narrowed artery. When the procedure is done on arteries in the neck
(the carotid arteries), it's known as carotid endarterectomy.
Thrombolytic therapy. If you have an artery that's blocked by a blood clot, your
doctor may insert a clot-dissolving drug into your artery at the point of the clot to
break it up.
Bypass surgery. Your doctor may create a graft bypass using a vessel from another
part of your body or a tube made of synthetic fabric. This allows blood to flow
around the blocked or narrowed artery
HOW TO PROTECT YOUR HEART?
1 .Limit how much saturated and trans fats you eat that contribute to
a buildup of plaque in your arteries
Types of Fat Recommendation
Saturated Fat Less than 7 percent of your total daily calories
Trans Fat Less than 1 percent of your total daily calories
Cholesterol Less than 300 milligrams a day for healthy adults; less than
200 milligrams a day for adults with high levels of low-density
lipoprotein (LDL), or "bad," cholesterol or those who are taking
cholesterol-lowering medication
The best way to limit saturated and trans fats is to limit the amount of
solid fats such as butter, margarine, and shortening. These are
commonly used and included into our foods. Avoid fried foods or use
substitutes where ever possible. For example use low-fat sour cream or
salsa on a baked potato instead of butter and sour-cream, or avoid
frying meats but rather broil, bake or barbeque instead. Use Olive oil
instead of shortening, and avoid deep fried foods or battered fried
foods..
Do check the food labels, especially those that are labeled "reduced
fat" because you may find that these items are substituting fat with
oils that contain trans fats. "Partially hydrogenated" is a typical phrase
that indicates trans fat so use this a a clue when reading those labels.
The healthier solution is to choose foods that contain
monounsaturated fats, such as olive or canola oil. Polyunsaturated fats
are found in nuts and seeds, which are also good choices. Both of these
types of fat may help to lower your total blood cholesterol - but with
moderation because these are still "fats."
2 .Choose from sources of low-fat proteins
Lean meats, skinless poultry and fish, or low-fat dairy products and egg
whites are your best sources of low-fat protein. Legumes (beans, peas
and lentils) are also great sources and contain less fat and no
cholesterol which makes them great alternatives to meat.
3 .More fruits and vegetables
Fruits and vegetables are is a great source for vitamins and minerals;
they are lower in calories and rich in fiber. Fruits and vegetables also
contain substances that help prevent cardiovascular disease. Eating
more fruits and vegetables will fill you up more, helping you to eat less
high-fat foods and snacks.
Eating more fruits and vegetables is actually easier than you think.
Choose recipes that include fruits and vegetables in them, keep apples,
grapes, peaches on hand and try new foods such as stir-fry, fruit salads,
or even canned fruits and vegetables (with lower sodium and sugar
content) Avoid drenching your fruits and vegetables in butter,
dressings, sugar, and sauces because these will add back fats and
calories which will in the end, defeat your purpose. Also try to avoid
breaded and fried vegetables, canned fruits in heavy syrup, and
coconut.
4 .Select whole grains
Whole grains are a great source of fiber, vitamins, minerals and iron.
The nutrients found in whole grains also help regulate blood pressure
and maintain your heart’s health.
Choose breads, pasta and cereals made from 100 percent whole grain
and avoid refined white flour. Select high-fiber breakfast cereals or
oatmeal instead of sugary cereals, muffins or doughnuts.
Flaxseed is another whole grain to add to your diet. Ground flaxseed is
high in omega-3 fatty acids which lower your total blood cholesterol.
You can easily add ground flaxseed to your foods by stirring in a
teaspoon over hot cereal, applesauce or yogurt.
5 .Reduce salt intake
Everyone uses it, it’s hard to avoid – eating a lot of salt can contribute
to high blood pressure. Reducing the salt in your food is an important
part of a heart-healthy diet. The American Heart Association
recommends that healthy adults eat less than 2,300 milligrams of
sodium a day which is about 1 teaspoon.
Salt is added to many foods that are canned, processed, frozen and
prepared. Snacks, chips, crackers, soups, frozen dinners all add salt to
improve flavor. The best way to reduce salt intake is to eat fresh foods
and making your own soups. Another way is to replace salt with salt
substitutes, herbs and spices or choose reduced-salt condiments or
prepared / processed foods.
6 .Eat in moderation
Yes, diet means eating in moderation. Overloading your plate, eating
till you feel stuffed or taking seconds leads to consuming more calories
and fat than you actually need. Eating out lends to eating more than
you should and often are foods that shouldn’t be consumed on a
regular basis. Use methods to keep track of your food intake, you’ll be
surprised by how much you consume and of what types of food you
eat regularly.
A heart-healthy diet also is about maintaining a balance, control and
moderation. Eating enough fruits and vegetables and not overindulging
with filler calories keeps our bodies healthy, not just our heart. It’s ok
to treat yourself to your favorite ice-cream or candy, just moderate
that to once a week and even then moderate the amount you
consume. Don’t let your favorite treat indulgence become an excuse to
abandon your healthy-eating plan but rather adopt healthy eating
habits as the norm.
7 .Create daily menus and plan.
Put your plans in action by creating daily menus. Using the strategies
listed above, emphasize vegetables, fruits and whole grains, choose
lean protein and limit high-fat and salty foods. Planning your meals
helps you to plan when you go to the store – having money as well.
Variety also helps make mealtime and snacks interesting .
Use these seven tips as a guide into a heart-healthy way to prevent
heart disease and you’ll be surprised how quickly you’ll be able to
regain control of your cholesterol. You’ll also be pleased by how easy it
can be to lose weight, as well. Incorporate healthy habits to create a
healthy life style.
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