In insulin resistance (IR) - which can
happen at any age - the cells of the body, particularly
the muscle and fat cells, become resistant to insulin causing the pancreas to
make more of the hormone. This increases the level of insulin in the blood and
can cause insulin resistance that can be measured and calculated by the HOMA
index.
What is the
HOMA Index?
The
HOMA index (Homeostatic Model Assessment of insulin sensitivity) is a
calculation based on the levels of serum fasting glucose and fasting insulin,
with insulin resistance defined as a HOMA index of >3.0.
The
Lab results for IR include the level of fasting Glucose, fasting Insulin, HOMA
(I.R.), the percentage of Beta cell activity and the Sensitivity of Insulin (a
measure of cells' reduced sensitivity to insulin).
What causes Insulin Resistance?
There
are several causes of insulin resistance including some medications (such as steroids).
However there is thought to be a strong genetic (inherited) factor as well. It is only in recent years that insulin resistance has been
gaining importance in its own right and as a contributor to the Metabolic Syndrome
(see below). Furthermore, insulin resistance may
precede the development of Type 2 Diabetes. IR is generally seen in the
following conditions:
- The Metabolic Syndrome, which
consists of a group of disorders such as obesity, lipid abnormalities (low
HDL and high LDL), high blood pressure & smoking. Patients with this
syndrome are usually overweight, with a Body Mass Index (BMI) of more than
25, and a waist of more than 101.6cm in men and more than 88.9cm in women.
- General Obesity
- Stress (including fatigue or
depression)
- Pregnancy or Polycystic Ovarian disease
- Fatty Liver
- Heart Disease including arteriosclerosis (hardening
of medium and large arteries).
What are the Symptoms of IR?
Some of the
following symptoms may be seen in patients with IR:
- Fatigue
(sometimes physical, but often mental).
- Inability to
focus
- High blood
sugar
- Intestinal
bloating. Insulin resistance sufferers who eat carbohydrates sometimes
suffer from gas.
- Sleepiness immediately
after eating a meal containing more than 20% or 30% carbohydrates.
- Weight gain,
fat storage, difficulty losing weight (with increased blood triglyceride
levels).
- Increased
blood pressure
- Depression
How
can I manage Insulin Resistance?
Insulin resistance can be
managed in two ways. First, the need for insulin can be reduced, and second, the
sensitivity of cells to the action of insulin can be increased. While there is sometimes
a genetic component, insulin resistance can usually be managed with:
-
Diet: such as adding Flavanol containing food (e.g.
cocoa beans, dark chocolate, red fruits and tea) since they decrease IR.
-
Exercise: as it reduces weight and improves the
sensitivity of cells to insulin.
-
Medication: such as Glucophage (by doctor
prescription only) as it prevents the liver from releasing glucose into the
bloodstream, and increases the sensitivity of muscle and fat cells to insulin
so that they remove more glucose from the blood.