Cholesterol and triglyceride are the two main components of fat and
fat-like substances called lipids. Abnormal lipid levels in the blood,
also called dyslipidimia, are linked to heart disease and other
diseases of the blood vessels, including stroke. Most people with diabetes,
especially type 2, tend to have a lipid disorder and are two to four times
more likely to have a heart attack or stroke than the general population.
However, a good control of blood cholesterol and triglycerides has been
shown to reduce this risk by 20 to 50 percent. The American Diabetes
Association (ADA) currently recommends that both people with type 2 and
type 1 diabetes should be given similar lipid lowering therapy to reduce
their risk for heart and blood vessel diseases.
MEASUREMENT OF LIPIDS. Lipids are measured in milligrams per
deciliter (mg/dL) or millimoles per liter of blood (mmol/L). Laboratories in
many countries, including the United States, measure cholesterol and
triglycerides in mg/dL. To convert mg/dL values into mmol/L values,
multiply mg/dL results by 0.0259. Although fasting or non-fasting blood
samples may have no impact on cholesterol measurement, triglyceride
levels are affected by eating. It is preferable that for a lipid profile test, you
should be fasting for 9 to 12 hours.
BLOOD CHOLESTEROL. Cholesterol in your blood comes from two
sources: diet, consisting of cholesterol-containing foods, and cholesterol
made by your liver. Most of the cholesterol your body needs (about 1,000
milligrams a day) is produced by your liver, whereas only a small amount
of cholesterol (about 400 to 500 milligrams per day) comes from your food.
By eating foods rich in cholesterol, you simply raise your blood cholesterol.
Total blood cholesterol measuring 240 mg/dL or greater is regarded a high
risk factor for heart disease and requires immediate and aggressive
EXCESS OF BLOOD CHOLESTEROL. When cholesterol in your blood is
high, the excess cholesterol tends to collect as fatty layers on the inner walls
of your arteries, raising their risk for clogging. Because of clogging, the
passage of an artery becomes narrow, and sufficient blood cannot pass
through. As the coronary arteries that serve the heart become clogged, the
heart does not get enough blood and oxygen, a condition that leads to heart
disease marked by chest pain called angina. When a clot forms in a clogged
coronary artery, it can block blood flow to a part of the heart, causing a heart
attack. Likewise, a clot, forming in the clogged arteries serving the brain,
can block blood flow to a part of the brain and cause a stroke.
The amount of total cholesterol in your blood is a strong indicator of the
health of your heart and blood vessels. Raised blood cholesterol increases
the risks for heart attack and stroke, whereas its lower levels reduce this risk.
TWO KINDS OF BLOOD CHOLESTEROL. Cholesterol, being a fat-like
substance, does not dissolve in theblood and cannot travel by itself into the
bloodstream. To transport cholesterol in the blood, your body coats
cholesterol with protein. Cholesterol that is coated with protein particles is
called lipoproteins, which are carriers transporting cholesterol in the blood.
The two important carriers that move cholesterol in the blood are called
low-density lipoprotein (LDL) and the high-density lipoprotein (HDL).
Total Blood Cholesterol
National Cholesterol Education Program (NCEP) classifies total
cholesterol in the blood into three categories:
Less than 200 mg/dL (5.2 mmol/L) Desirable
200 to 239 mg/dL Borderline high
240 mg/dL or greater High
LDL CHOLESTEROL. Low-density lipoprotein (LDL) contains more cholesterol
than protein. LDLs are the major carriers that move about 70 percent
of cholesterol in your blood and transport it from the liver to the
arteries. LDL cholesterol is called bad cholesterol because when its level is
high in the blood, it tends to build up fatty deposits on the walls of the
arteries and clog them. Raised LDL cholesterol is the key factor contributing
to heart and blood vessel diseases, and it is regarded as the most reliable
indicator of the risk for heart attack and stroke. Even if your total cholesterol
is in the desirable range, raised LDL cholesterol poses a high risk for
CAUSES OF RAISED LDL CHOLESTEROL.The causes include:
• Eating foods high in saturated fat and cholesterol
• Insufficient production of thyroid hormones, a condition known as
• Genetic disorder. One out of 500 adults has a genetic tendency of
having raised blood cholesterol. Restriction of dietary cholesterol
The NCEP classifies LDL cholesterol levels into six categories:
Less than 70 mg/dL (1.8 mmol/L) *Optional
Less than 100 mg/dL (2.6 mmol/L) Optimal (Best)
100 to 129 mg/dL Near optimal
130 to 159 mg/dL Borderline high
160 to 189 mg/dL High
190 mg/dL or greater Very high
- (May be considered for high risk people, including people with
diabetes who have heart disease.)
does not reduce blood cholesterol in these people, and they must be
treated with cholesterol lowering drugs
• Excessive excretion of albumin in the urine
TREATMENT OF RAISED LDL CHOLESTEROL. Cholesterol-lowering
therapy mainly aims to lower raised LDL (bad) cholesterol levels, thereby
reducing the risk for heart attack and stroke.
Before starting LDL-lowering therapy, you should be screened for the
secondary causes that may be responsible for raised LDL cholesterol. The
secondary causes may include such conditions as lack of thyroid hormone
and excessive excretion of albumin in the urine. Secondary causes, if
present, should be treated first. Oral replacement of thyroid hormones, for
example, can treat insufficiency of thyroid hormones. To treat kidney
damage and control leakage of albumin in the urine, measures such as
reduced intake of protein, use of ACE inhibitors (see chapter 21), and
control of blood sugar will be helpful.
The aim of LDL-lowering therapy in people with diabetes is to bring
down raised LDL cholesterol to:
• Less than 100 mg/dL (2.6 mmol/L)
• Less than 70 mg/dL(1.8 mmol/L) if these people have heart disease
In achieving the above targets, the NCEP suggests to initiate drug therapy.
However, lifestyle changes such as nutritional measures, healthy weight,
and exercise must remain an essential part of the treatment plan.
NUTRITIONAL MEASURES. The following nutritional measures are
helpful in lowering LDL (bad) cholesterol:
Low Fat Low Cholesterol Diet. Limit your intake of saturated fat and
cholesterol. The NCEP currently recommends a reduced intake of saturated
fats and cholesterol: saturated fat less than 7 percent of your total calorie
need, and cholesterol less than 200 milligrams per day. However, currently,
the Institute of Medicine suggests even more strict restriction on the use
of saturated fat and cholesterol. According to the Institute, you do not need
cholesterol and saturated fat in a healthy diet, and if these nutrients are used
at all, use them sparingly. You can achieve these dietary goals by following
the new food pyramid (see chapter 7).
Soy Protein. Soy protein is helpful in reducing LDL cholesterol. In a blood
cholesterol-lowering plan, you may include soy protein foods such as soy
milk, tofu, soy beans, tempeh, and miso. As suggested by the FDA, take
these foods in a quantity that supplies 25 grams of soy protein per day. This
quantity may be divided into 2 to 4 servings; each serving should have at
least 6.25 grams of soy protein to get heart health benefits. As noted earlier,
4 oz of tofu provide 13 grams, a glass of soy milk provides 10 grams, and
1/4 cup of roasted soy nuts provides 19 grams of soy protein.
Nuts. You may take about 1/3 cup of unsalted mixed nuts in place of
saturated fat and trans fat within your calorie allowance, 3 days per week .
Nuts are high in monounsaturated (good) fat, which when used in place of
harmful saturated fat, helps reduce raised LDL cholesterol. Remember,
however, that nuts are high in calories and even their slight overuse will
cause unhealthy weight gain. So eat nuts sensibly.
WEIGHT REDUCTION. Lose weight if you are overweight or obese. Even
a moderate weight reduction will contribute to reduce blood levels of LDL
cholesterol and triglyceride, and increase your HDL (good) cholesterol. All
these effects will be beneficial in reducing your overall risk for heart
disease, stroke, and other complications of diabetes.
EXERCISE. Regular exercise helps control weight and blood sugar, reduce
high blood pressure, and improve blood lipids, including LDL cholesterol.
All these benefits will decrease your risk for heart and blood vessel diseases.
For most people, a combination of aerobic and muscle-strengthening
exercises (such as walking and lifting of manageable weights) will provide
maximum health benefits, including control of blood fats and cholesterol.
DRUG THERAPY. There are five classes of lipid-lowering drugs:
• HMG-CoA reductase inhibitors, popularly known as statins (see
• Bile acid sequestrants, which include cholestyramine, colestipol,
• Fibric acid derivatives, including gemfibrozil, fenofibrate, and
• Niacin or nicotinic acid, which includes immediate release,
extended release, and sustained release nicotinic acid
Statin Drugs. Among all the classes of cholesterol lowering drugs, statins
are the newest and most popular class of drugs. These drugs work in the
liver to lower LDL cholesterol. Statins include:
Benefits of statins. Statins have been shown to be very effective in lowering
LDL cholesterol, slowing progression of hardening of the arteries, and
reducing deaths from heart disease and stroke. Statin drugs are now the
drugs of choice in treatment of raised LDL cholesterol. These drugs:
• Reduce LDL cholesterol by about 18 to 55 percent
• Increase good cholesterol (HDL cholesterol) by about 5 to 15
• Decrease triglyceride levels by about 17 to 30 percent
Dose. The dose of statin drugs should be adjusted at 4 to 6 weeks till LDL
cholesterol is reduced to the target level. In an intensive cholesterollowering
therapy, first maximize the dose of statins, then add a second class
of drug such as a bile acid sequestrant or niacin. An important point is that
LDL-lowering therapy should be sufficiently intensive so that it can achieve
at least 30 to 40 percent reduction in LDL cholesterol levels. To achieve this
target, standard daily doses of statins are required, which, for example, can
Name Brand Name
include any one of the following options: atorvastatin 10 mg, fluvastatin 40
to 80 mg, lovastatin 40 mg, pravastatin 40 mg, simvastatin 20 to 40 mg, or
rosuvastatin 5 to 10 mg.
Side effects. Statin drugs may increase liver enzymes and cause muscular
weakness in some people. Both these conditions normalize on stopping the
use of these drugs. Cerivastatin (Baycol), a drug of the statin family, was
withdrawn from the market in 2001, because it was found associated with
several deaths from muscle cell breakdown. However, the NCEP, in its
current update, reports that adverse side effects of LDL-lowering therapy
with statins are very rare, whereas its advantages are proven. Statin therapy
is generally well tolerated by elderly people aged 65 years to 80 years.
Intensive statin therapy in these people, however, should be initiated under
careful medical supervision
Caution. In the presence of liver disease and severe kidney disease, statins
should be used with caution. In moderate kidney disease, statins should be
used in the lowest dose. You should have a liver function test before
starting therapy with statins, and periodically thereafter during the treatment
with these drugs. Do not eat grapefruit or drink its juice while you are on a
statin drug. Grapefruit juice keeps statins from clearing from the body,
increasing their levels in the blood, thereby heightening the risk of muscle
Niacin. Nicotinic acid or niacin is a component of the vitamin B complex.
Sometimes when full doses of statins fail to bring down raised LDL cholesterol
below 100 mg/dL, addition of niacin will accelerate reduction of these
levels. Also, niacin reduces total cholesterol and triglycerides, and raises
HDL (good) cholesterol in the blood.
But, niacin in combination with statins may raise the risk for severe
liver inflammation. For this reason, while using niacin-statin combined
therapy, liver function should be monitored more frequently. Niacin may
have another side effect also; it may raise blood sugar in some people with
diabetes. This is the reason that when you use niacin to control lipid levels,
you should keep track of your blood sugar by regular monitoring. Other side
effects of niacin may include stomach discomfort, inflammation of the
joints, and uncomfortable flushing. Aniacin preparation, namely, Niaspan is
available in an extended-release once-at-night dosing of niacin with
minimal side effects.
HDL CHOLESTEROL. High-density lipoprotein (HDL), which mainly
consists of protein and less of fat, handles about 25 percent of the total
cholesterol in your blood.
Unlike LDL that carries cholesterol to the arteries, HDL picks up LDL
cholesterol deposited on the inner walls of the arteries and other tissues, and
carries it away to the liver for excretion. This cleaning action of HDL
cholesterol has a protective effect on your heart and brain, reducing your
risk for heart attack and stroke. For this protective effect, HDL cholesterol
is called good cholesterol. Low HDL cholesterol levels are a strong and
The CARDS Trial
Statin Drug Prevents Heart Disease in People with Type 2 Diabetes
The recent landmark study known as CARDS (Collaborative
Atrovastatin Diabetes Study) has shown that atorvastatin (Lipitor) in
low doses is effective and safe in preventing heart disease in people
with type 2 diabetes at high risk. The study suggests that almost all
people with type 2 diabetes should receive cholesterol-lowering
therapy regardless of their LDL (bad) cholesterol levels. Even when
your LDL cholesterol is less than 3.0 mmol/L ( less than 116 mg/dL) or
even lower than 2.6 mmol/L (less than 100 mg/dL) and you have type
2 diabetes, you are at risk of heart disease. This study, along with the
American College of Physicians, questions the trend in doctors who
prescribe cholesterol lowering drugs in individuals with type 2 diabetes
only on the basis of their blood cholesterol levels. To repeat, the study
suggests that cholesterol lowering therapy with atorvastatin should be
started in people with type 2 diabetes regardless of their LDL
independent risk factor for heart disease and stroke. New research is
showing that raised blood levels of HDL (good) cholesterol not only help
prevent heart disease, but also reduce blockages in the coronary arteries,
thereby improving heart health. The NCEP recommends HDL-raising
therapy for people with diabetes.
CAUSES OF LOW HDL CHOLESTEROL. The causes include:
• Meals very rich in carbohydrates in which carbohydrate content is
more than 60 percent of calories
• High triglyceride levels
• Physical inactivity
• Cigarette smoking
• Certain drugs such as beta-blockers used to treat high blood
pressure and steroids
TREATMENT OF LOW HDL CHOLESTEROL. HDL(good) cholesterol
below 40 mg/dL is associated with increased risk for heart attack and stroke.
The NCEP recommends that in the presence of lipid disorders, low levels of
HDL cholesterol should be treated in the following sequence:
• First, reduce raised LDL (bad) cholesterol to the target goal.
• Next, reduce weight (if you are overweight), and increase physical
The NCEP classifies HDL cholesterol levels into two categories:
Less than 40 mg/dL ( 1.1 mmol/L) Low (bad for your heart)
in men, and less than 50 mg/dL
(1.3 mmol/L) in women
60 mg/dL or greater High (good for your heart)
activity. Both these steps are very beneficial in raising HDL
• If triglycerides are high along with low levels of HDL cholesterol,
reduce your triglyceride levels (see below for triglyceride).
• When triglycerides are or have been reduced to less than 200
mg/dL, drugs called fibrates such as gemfibrozil (Lopid), fenofibrate
(TriCor), and clofibrate (Atromid-S) may be added to statins to treat
low HDL cholesterol.
• Fish, flaxseed oil, and niacin are helpful in raising HDL cholesterol.
Recent research shows that niacin in a daily dose of 750 to 2,000
milligrams is highly effective in raising HDL cholesterol without
much adverse effect on blood sugar.
CHOLESTEROL RATIO. Some physicians use the cholesterol and HDL
ratio (cholesterol/HDL) to evaluate the risk for heart disease. To derive this
ratio, divide total blood cholesterol by HDL cholesterol. By this calculation,
if your total cholesterol in the blood is 300 mg/dL and HDL cholesterol is
50 mg/dL, the cholesterol/HDL ratio will be 6:1. The normal range is a ratio
below 5:1. A higher ratio indicates increased risk for heart disease.
TRIGLYCERIDE. Triglyceride is fat that comes in your blood from two
sources: fat in your diet and the fat your body makes. When you eat more
food than your body immediately needs for energy, a part of the excess
energy is converted into fat (triglyceride) and stored in the cells of your
body for future use.
Triglyceride circulates in the blood mainly in the form of very lowdensity
lipoprotein (VLDL). The VLDLs are more of triglyceride and
less of cholesterol and protein. Raised triglyceride level in the blood is
the most common lipid abnormality found in people with type 2 diabetes
and an independent risk factor for heart disease. Triglyceride levels,
greater than 1,000 mg/dL in the blood, may cause a serious inflammatory
disease of the pancreas called pancreatitis.
CAUSES OF RAISED TRIGLYCERIDE LEVELS. The causes include:
• Poor control of blood sugar. (Sometimes high blood sugar may be
the sole cause of raised triglycerides)
• Kidney damage
• Excessive consumption of alcohol
• Physical inactivity
• Excessive intake of carbohydrates
• Meals rich in saturated fat and cholesterol
• Cigarette smoking
TREATMENT OF RAISED TRIGLYCERIDES. Borderline-high blood levels
of triglyceride (150 to 199 mg/dL) are generally normalized when you:
• Control your blood sugar
• Reduce fat intake
• Stop or limit alcohol consumption
• Become physically active, and exercise regularly
• Reduce weight if you are obese or overweight
When blood triglycerides are very high (500 mg/dL or greater), or when
nutrition and lifestyle changes have failed to lower raised triglycerides,
drug therapy should be added. For the drug therapy to be effective, healthy
eating and exercise should remain in place to support the treatment.
Fibrates (noted before) are usually the first choice in drug treatment of
raised triglyceride levels. Gemfibrozil (Lopid) is the fibrate most widely
used in the United States. These drugs limit the formation of fatty
substances in the body, thereby leading to reduction of triglycerides in the
blood. Fibrates, however, may have some side effects, including indigestion,
formation of gallstones, and muscle degeneration. Use of fibrates is not
recommended in severe kidney damage, and in this condition, niacin in
a dose of 750 to 2,000 milligrams per day may be used to treat raised
HOW TO PREVENT LIPID DISORDERS. Unless the lipid disorder is
exclusively genetic (which is rare), you will be able to achieve and
maintain your total cholesterol, LDL cholesterol, HDL cholesterol, and
triglyceride within normal ranges, when you:
• Achieve and maintain a healthy weight.
• Take a low fat and low cholesterol diet:
– Avoid high cholesterol foods such as egg yolk, and organ meats.
– Choose chicken and fish without their skin instead of beef and
– Use fat free or low fat milk instead of whole milk.
– When you choose to use margarines, choose the ones made of
vegetable oil as the first ingredient.
– Do not fry foods; bake, broil, roast, or steam.
– Use raw or cooked vegetables because they are nourishing.
– Choose plant oils, which are rich in monounsaturated (good) fat.
• Take 2 servings of oily fish per week. This much fish will provide you
sufficient amount of omega-3 fatty acids that will help raise your good
cholesterol and reduce triglycerides.
• Stop or limit consumption of alcohol to lower blood triglycerides.
• Exercise regularly such as 30-60 minutes of brisk walking each day.
• Stop smoking if you currently smoke.
• Achieve and maintain good blood sugar control.
Watch your lipid levels. You should have a lipid profile test at least
every year and more frequently if you have a lipid disorder. Keeping your
The NCEP classifies fasting levels of blood triglyceride into
Less than 150 mg/dL ( 3.9 mmol/L) Normal
150 to 199 mg/dL Borderline-high
200 to 499 mg/dL High
500 mg/dL or greater Very high
blood cholesterol and triglyceride within normal ranges is extremely helpful
in reducing your risk for heart attack and stroke; it is all the more crucial
when you have diabetes.