Insulin resistance occurs when insulin levels remain elevated
over a prolonged period of time, thereby inducing a reduction in the body’s own
sensitivity to the hormone.
Higher circulating
levels of insulin in the blood stream and gaining weight help to exacerbate
further insulin resistance.
Insulin resistance is
closely linked with inflammation, which is a byproduct of the body’s attempt to
heal itself. It is hypothesized that in the cases of pre-diabetes (characterized by the presence of levels of blood glucose
that are elevated, but not yet high enough to be classed as
diabetes) and type 2
diabetes, the body’s immune system releases chemicals known as cytokines, which
is thought to interfere with the normal action of insulin on tissues (insulin
triggers tissues to uptake glucose for use or storage). Therefore, lower
insulin sensitivity and increasing insulin resistance.
As a
result, muscle, fat, and liver cells do not respond properly to insulin and
thus cannot easily absorb glucose from the bloodstream. Consequently, the body requires
higher levels of insulin to help glucose enter cells.
The beta
cells in the pancreas (these cells manufacture insulin) attempt to make up for
this alteration by increasing insulin production. So long as the beta cells are
able to keep up with the body’s demands of insulin, blood glucose levels can be
maintained in the normal range.
Over
time, however, the beta cells decompensate because they can no longer keep up
with the body’s increased need for insulin. The result is: pre-diabetes or type
2 diabetes.
The major
contributors to insulin resistance are excess weight and physical inactivity.
Excess Weight
Mainly
abdominal fat (assessed by measuring the waist circumference) more importantly
than overall excess weight (assessed by the body mass index). Abdominal fat produces
hormones and other substances that can cause serious health problems such as
insulin resistance, high blood pressure, imbalanced cholesterol, and
cardiovascular disease (CVD).
Physical Inactivity
Many
studies have shown that physical inactivity is associated with insulin
resistance, often leading to type 2 diabetes. Moreover, recent studies have
demonstrated that physical inactivity despite normal weight is by itself a risk
factor for chronic diseases. In the body, the muscles are the principal
consumers of glucose. Normally, active muscles require burning of glucose to
fuel their activity, and replenish their glucose reservoir by absorbing glucose
from the bloodstream.
After
exercising, muscles’ sensitivity to insulin in enhanced, reversing insulin
resistance and lowering blood glucose levels. Exercise also helps muscles
absorb more glucose without the need for insulin. The more muscle a body has,
the more glucose it can burn to control blood glucose levels.
Other Causes
Other
causes of insulin resistance may include ethnicity; certain diseases; hormones;
steroid use; some medications; older age; sleep problems, especially sleep
apnea; and cigarette smoking.
Fortunately,
routine and consistent physical activity along with losing and maintaining a
healthy weight help the body respond better to insulin.
Two approaches for preventing diabetes:
·
Making lifestyle changes: walking 5 days a week for
about 30 minutes a day, and lowering intake of fat and calories.
·
Taking the diabetes
medication metformin.: as indicated by a
physician
Losing about
8 Kg in the first year, the risk of developing type 2 diabetes can be reduced by
58% over 3 years.
