
Glucose/Insulin
Metabolism in Health and Disease
Mastering
the Metabolic Syndrome
Glucose is our major source of
energy. Proteins and fats cannot be used to produce energy
until first transformed into glucose by biochemical
processes in our bodies. Glucose is taken in to the cells
of our body and transformed into smaller molecules that
are the final common pathway for energy production.
Our cells require insulin in order to
facilitate the uptake of glucose. Insulin is a hormone
secreted by our pancreas. It is secreted in response to a
rise in glucose in our serum. It activates “insulin
receptors” on our cell walls. These receptors signal our
genetic material to produce molecules that transport
glucose into our cells where it is processed.
When glucose insulin function becomes
inefficient there is an increased risk to diabetes and a
variety of other chronic health problems such as obesity,
hypertension, heart attack, stroke and cancer.
In Type 1 Diabetes the pancreas fails
to make an adequate amount of insulin. In Type 2 diabetes
the pancreas makes an adequate amount of insulin but the
cells of the body lose their sensitivity to the insulin
message and blood sugar rises. Ultimately, the pancreas
loses its ability to make insulin and the blood sugar
stays elevated because of an inadequate amount of insulin.
Dysfunction of glucose insulin metabolism is not an on or
off phenomena. It is not true that we either have the
problem or we don’t. We are talking about a continuum
from optimal function to overt illness.
There are a variety of names given to
this phenomenon. Dr. Gerald Reaven was one of the first
scientists to describe the problem. He referred to the
reduced sensitivity of the cells to the insulin message as
“insulin resistance”. This meant that while a person
makes enough insulin, the insulin receptors on the cell
membranes have a reduced sensitivity to the insulin
message. As a result the person must make an excessive
amount of insulin in order to control blood sugar,
(glucose levels in the blood). He named the clinical
pattern of individuals with the problem; Syndrome X. This
name has evolved to Metabolic Syndrome. Individuals with Metabolic Syndrome have a constellation of
findings, which include central obesity, (fat tissue
around the waist and within the abdominal cavity),
hypertension, high triglycerides, and low HDL cholesterol.
These individuals are at increased risk of developing
diabetes, arteriosclerosis, heart attack, and stroke.
About 20-30% of the population is
genetically predisposed to insulin resistance. Some but
not all of these people will develop the pattern of
abnormal physical findings, laboratory findings and
diseases characterized by Metabolic Syndrome. A
predisposition means that there is a greater chance that
the problem of insulin resistance will develop during an
individual’s lifetime. Not everyone with the
predisposition will develop the problem.
Factors that can lead to the
manifestation of insulin resistance in a predisposed
individual include stress, diet, and
activity level. This
means that susceptible individuals can be identified and
can minimize the adverse health consequences of insulin
resistance with appropriate life style changes.
Insulin Resistance can lead to Type 2
diabetes with the adverse consequences of heart disease,
stroke, kidney disease, eye diseases, and peripheral
artery insufficiency.
Insulin Resistance is a factor in
other health problems that can occur without the
development of overt Diabetes. These problems include
Obesity, Hypertension, Arteriosclerosis, Heart Attack,
Stroke, Cancer, and Accelerated Aging.
Historical Factors that Suggest
Insulin Resistance
A family history of diabetes,
premature heart disease, hypertension, blood fat
abnormalities, menstrual irregularity, infertility or
Polycystic Ovary Disease may indicate a personal
vulnerability to insulin resistance/metabolic syndrome.
A personal history of diabetes,
premature heart disease, hypertension, blood fat
abnormalities, menstrual irregularity and or fertility
problems, or Polycystic Ovary Disease may be associated
with insulin resistance. Individuals who have problems
with weight control often have insulin resistance as
contributing factor to the problem.
Signs and Symptoms of Insulin
Resistance
-
Difficulty in controlling or
maintaining body weight despite good dietary practice
-
Obesity of the central type; the
waist circumference is greater than the hip circumference
-
(Measure your abdominal circumference
at the level of the belly button, (umbilicus), measure
your hip circumference at the widest point of the hips)
-
Hypertension, (systolic blood
pressure greater than 140, diastolic blood pressure
greater than 90)
-
Fatigue one to three hours after
eating
Insulin Resistance is not a disease.
It is an abnormality of normal metabolism. As such, it
does not have classical disease symptoms. As noted above,
it can be a contributing factor to many chronic diseases.
Laboratory Findings in Insulin
Resistance
-
Elevation of fasting and two-hour
post-prandial blood sugar, (the blood sugar obtained two
hours after eating)
-
Most individuals with adult onset
diabetes had insulin resistance prior to the onset of
their diabetes and have insulin resistance as part of
their diabetic problem.
-
Elevations in fasting insulin and
two-hour post-prandial insulin
-
When insulin levels are
inappropriately elevated in comparison to the blood sugar
we can diagnose insulin resistance.
-
We will typically do a two-hour
glucose/insulin tolerance test when we suspect insulin
resistance.
-
Protein C is a remnant particle of
insulin. When elevated it suggests insulin resistance and
excess circulating insulin.
-
Lipid, (blood fat), abnormalities
associated with insulin resistance include
-
Elevated Triglycerides
-
Low HDL levels
-
An increase in small dense LDL
particles these are a sub-fraction of the undesirable
transport protein for cholesterol that significantly
increases risk to heart disease even when cholesterol is
relatively low.
-
Coagulation abnormalities associated
with insulin resistance include
-
Increased levels of fibrinogen
-
Elevated PAI-1, (plasminogen
activator inhibitor-1)
-
The cumulative effect of these
abnormalities is to make the blood stickier and to promote
arteriosclerosis.
The Treatment of Insulin
Resistance
Dietary Measures
Obesity is a contributing factor to
the manifestation of Insulin Resistance but it does not
cause insulin resistance Weight loss, no matter how
modest, will improve glucose insulin metabolism. In
individuals who are obese we recommend modest calorie
restriction to achieve a gradual and sustained weight
loss.
Please see our section on Diet and
Nutrition for general recommendations.
The basic principles of a good diet
include:
Modest calorie intake
Carbohydrates should contribute
40-50% of total calories. Emphasize foods that are
unprocessed and low in refined sugar and refined starches.
Minimize calories from candy, soft drinks, pastries and
dairy desserts. Do not add sugar to beverages or breakfast
cereals. Minimize calories from refined carbohydrate
sources such as white flour, white rice and potatoes.
Avoid snack foods such as pretzels, corn chips, potato
chips, etc.
Fats should provide an important
source of calories, (up to 30%). Try and minimize
saturated fats found in processed meats, feed lot fed
animals, fried foods, baked goods and rich dairy desserts.
Fats from vegetable sources such as olive oil, nuts and
seeds are considered healthful. Fats from deep-sea fish
and sea vegetables are considered healthful.
Protein is essential to good health.
The idea that a diet rich in protein will prevent obesity
or improve insulin resistance has not been verified by
scientific studies. Protein can be obtained from red meat,
poultry, seafood, and vegetable sources. A varied diet
that emphasizes, foods that are organic and unprocessed is
most desirable.
Exercise
A modest exercise
program will
improve metabolism and aid in preventing the expression of
Insulin Resistance in individuals at risk. Walking for 30
minutes per day is adequate. For those who cannot walk I
recommend riding a stationary bicycle for 30 to 45
minutes. The benefit of exercise only exists while you are
exercising regularly. Consistency is the key to achieving
benefit.
Dietary
Supplements that may improve
Insulin Resistance:
Vitamins
-
An Anti Oxidant multivitamin will
reduce oxidative stress and reduce the adverse health
effects of insulin resistance. I recommend a product
called SEVAK in a dose of 2 capsules at breakfast and 2
capsules at lunch.
-
Biotin is a B vitamin that may be
helpful in a dose of 5000-10,000 micrograms per day. It
should be taken with Alpha Lipoic Acid.
-
Alpha Lipoic Acid in a dose of
200-400 mgs twice daily with meals will help improve
insulin resistance.
Minerals
-
Calcium emphasize food sources.
Consider a modest supplementation of 600 mgs per day in
addition to food sources unless there is another
indication for higher doses such as bone loss.
-
Chromium this is a trace mineral
that has been shown to improve blood sugar and insulin
resistance. The therapeutic dose is 400-800 micrograms per
day.
-
Magnesium Magnesium deficiency is
common in our country. We recommend supplementation with
200-400 mgs per day.
-
Vanadium this is a trace mineral.
The minimal daily requirement is not large. The dose
needed to improve glucose insulin metabolism in not
nutritional but pharmacological, (5 mgs. per day). It
should be used under the supervision of a health care
practitioner.
-
Zinc the recommended dose is 30 mgs.
per day. I do not currently recommend this product because
the long term safety data is not established.
Fats:
Certain fats can improve cell
membrane sensitivity to insulin.
-
Eicosapentaenoic acid, (EPA), is
derived from fish oil. The recommended dose is 3-6 grams
per day in divided doses.
-
Conjugated Linoleic Acid this is a
fat derived from animal sources. It has been shown to
improve insulin sensitivity, improve glucose transport
across the cell membrane and lower triglycerides. The
recommended dose is 2 grams three times per day with
meals.
Nutrients: There are “conditionally
essential” nutrients that are helpful in optimizing
glucose metabolism.
-
Lipoic acid in a dose of 300-1200 mgs
per day in divided doses
-
Coenzyme Q 10 in a dose of 100 mgs
per day
-
L-Carnitine in a dose of 500 mgs two
times per day
-
Taurine in a dose of 500 mgs two
times per day
-
Milk Thistle and Panax Ginseng,
(Korean Ginseng), are herbal products that are helpful in
improving glucose metabolism
Ultraglycemics is a nutritional food
product that can be used as a snack and or a meal
substitute. It is specifically designed for people who
have problems with glucose insulin metabolism.
Hormonal Factors that may affect
Insulin Resistance
Stress is a natural part of life.
Chronic, persistent stress is an important contributing
factor to poor health, chronic illness and accelerated
aging. With chronic persistent stress a hormonal pattern
evolves that increases insulin sensitivity. The adrenal
gland makes cortisol, which is a catabolic hormone. Among
other actions, it increases glucose and creates an
environment where insulin resistance can manifest.
Catabolic hormones increase with chronic stress, chronic
illness and the aging process. Anabolic hormones are made
by the adrenal gland as well. The dominant anabolic
hormone is DHEA. DHEA is a precursor to the sex hormones
such as testosterone and estrogen. Other metabolites of
DHEA support optimal thyroid function and immune function.
DHEA declines with chronic stress and the aging process.
When the DHEA level is low, careful supplementation with
physiological doses may improve body composition, general
well-being and glucose insulin metabolism.
Insulin Resistance is present in
20-30% of the population. It is a contributing factor to a
variety of chronic health problems and the aging process.
Individuals with Insulin Resistance can be identified. The
problem can be managed through life style modification and
appropriate nutritional supplementation.
|