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It is believed
by many that
improperly unmanaged stress is a major determinant in almost all
illness conditions. The question we ask is "Does stress also leads to diabetes?"
We shall
investigate.
We can classify diabetes into two major types:
type 1 diabetes mellitus and
type 2 diabetes mellitus.
Type 1 diabetes mellitus is commonly known as juvenile diabetes because
it starts when the sufferers are still young, as children and young adults. It is
the result of insufficient
amount of insulin being produced (the condition is known as insulin deficiency).
Since it starts early in life, we can safely conclude that
type 1 diabetes mellitus is unlikely to be caused by stress.
Type 2 diabetes mellitus usually occurs later in life, usually after the age
of forty. Type 2 diabetes mellitus is the most common form of
diabetes. In type 2 diabetes mellitus, the problems arise because
1. Either the body does not produce enough insulin, or
2. The insulin produced is ignored by the cells in the body (known
as insulin
resistance), or both.
Discussion on what insulin is and what the roles it plays is in
order.
Insulin is a hormone that regulates carbohydrate metabolism (and to
some extent fat metabolism as well). Insulin helps the body to use
sugar. Sugar is the basic source of energy for the cells in the
body, and insulin takes the sugar from the blood into the cells.
When we say blood sugar, we refer to glucose in the blood. Glucose
is the main type of simple sugar in our blood. Our body needs to
have glucose level controlled to within a narrow range (0.7-1.1 mg
per ml). Below 0.7 mg per ml is deemed to be too low for the body to
function properly and the condition is termed "hypoglycemia".
When the glucose level in the blood is above 1.8 mg per ml, it is
deemed to be too high for hte body to function properly and the
condition is termed "hyperglycemia". Both can result in problems as
we shall see later.
When there is more glucose in the blood, more insulin is secreted
into the blood, resulting in cells (muscle cells, red blood cells
and fat cells) absorbing the glucose out of the blood, thus reducing
the blood glucose level.
When there is less glucose in the blood, more glucagon (counter part
of insulin) is secreted into the blood, stimulating liver to release
the glucose it has stored in its cells into the blood stream, thus
increasing blood glucose. Glucagon also induces the liver and some
of the muscle cells to produce glucose out of protein.
If the glucose does not go into cells, instead it builds up in the
blood resulting in hyperglycemia, two problems arise.
1.If the cells do not get
the glucose they need, they die.
2. Prolong period of high
blood glucose levels may hurt your eyes, kidneys, nerves or heart.
Insulin is used to treat this "hyperglycemia" aspect
of diabetes.
"Hypoglycemia" or low blood glucose level condition can happen when
more insulin is introduced than there is food in the stomach to be
acted on. This often happens when a patient injects insulin in
anticipation of food consumption, but the food consumption is
delayed or insufficient food is consumed. Symptoms of "hypoglycemia"
include strange behavior, clumsy or jerky movements, seizure,
confusion, tingling sensations around the mouth, dizziness,
sweating, headache etc. A diabetes patient under this
condition can be a danger to himself/herself, and can be a danger to
others too if he/she is performing tasks such as driving or
operating a machine.
Now that we understand the mechanics of diabetes, we are in a better
position to examine whether there is anything to suggest that stress
can cause diabetes (type 2).
The usual reason explaining why stress lead to sickness is the
weakening of our immunity system caused by stress. However, diabetes
is not caused by weak immunity system.
Psychological stress caused by the death of a spouse, a financial
crisis or other life-altering event has been associated with higher
risk of developing diabetes in middle age. Many studies have shown
that the abovementioned types of major life events were associated
with type 2 diabetes regardless of family history of the disease,
exercise or alcohol use. However, although such circumstantial
evidence seems to suggest a link between a higher proportion of
people under greater stress and diabetes, we cannot conclude that
stress cause diabetes. In another word, association does not
imply causation.
There is a theory that says that stressful life events increase the
diabetes risk by increasing levels of the hormone cortisol and
decreasing levels of sex steroids such as testosterone, which have
been shown to influence the action of insulin.
To test the above theory, some researchers have tried to determine
whether stress, which can be measured using the ratio
cortisol:testosterone, affects insulin resistance. In the
prospective study by George Davey Smith and colleagues from the
University of Bristol in the United Kingdom, cortisol:testoterone
ratio was positively associated with IHD (ischemic heart disease)
mortality and incidence. Adjustment for potential socioeconomic and
behavioral confounding variables had little influence on these
associations, but they appeared to be mediated by components of the
insulin resistance syndrome (elevated blood pressure, triglyceride
levels, body mass index, total cholesterol, HDL cholesterol, and
impaired glucose tolerance). This suggests that methods of reducing
the cortisol:testoterone ratio may improve insulin resistance and
reduce the risk of ischemic heart disease (IHD). But, it does not
suggest that reducing stress can reduce the risk of diabetes or vice
versa. Instead, the experiment results show that increase
stress level can lead to increase insulin resistance of a diabetes
patient, but does not increase the insulin resistance of a healthy
person until he develops diabetes.
More conclusive research findings will be needed before we can
conclude that stress does indeed lead to diabetes. |
