C H A P T E R 3 8
Agents to control blood glucose levels
577
increase in type 2 diabetes in young people. The treat-
ment of Type 2 diabetes usually begins with changes
in diet and exercise. Dieting controls the amount and
timing of glucose introduction into the body, and weight
loss decreases the number of insulin receptor sites that
need to be stimulated, as well as the intra-abdominal fat
that blocks adiponectin release. Exercise increases the
movement of glucose into the cells by sympathetic nervous
system (SNS) activation and by the increased potassium
in the blood that occurs directly after exercising. Potas-
sium acts as part of a polarising system during exercise
that pushes glucose into the cells. Clinical studies have
shown that controlling serum glucose levels can decrease
the risk of complications by up to 40% (ADA, 2008).
When diet and exercise no longer work, other agents
(discussed later) are used to stimulate the production
of insulin in the pancreas, increase the sensitivity of the
insulin receptor sites, or control the entry of glucose
into the system. Injection of insulin may eventually
be needed. This concept is often confusing for people
who are learning about diabetes. Type 2 diabetes often
evolves until insulin is needed. Timing of the injections
of insulin is correlated with food intake and anticipated
increases in blood glucose levels, as well as exercise
levels and anticipated stress (ADA, 2008). See Box 38.4
Diabetes and blood glucose variations
Certain ethnic groups tend to have a genetically
predetermined variation in blood glucose levels, possibly
caused by a variation in metabolism. In New Zealand,
certain ethnic groups (particularly Ma– ori, Pacific Islanders
and South Asians) are at a higher risk of developing
diabetes and data suggests that the incidence of diabetes
for Ma– ori and Pacific peoples are more than three
times higher than the European rates and Ma– ori and
Pacific peoples are more than five times as likely to die
from type 2 diabetes. Similarly, it has been estimated
that Indigenous Australians have a three times higher
incidence of type 2 diabetes than the non-Indigenous
population, and are twice as likely to die from a diabetes-
related condition. People in these groups should be
screened regularly for type 2 diabetes.They can also
benefit from teaching about warning signs of diabetes.
Beyond Australia and New Zealand, similar problems
exist for many cultural groups including First Nation
people in Canada, and African and Native Americans.
The clinical importance of this relates to proper
screening of individuals for hypoglycaemia and diabetes
mellitus. Individuals in these groups who have fasting
glucose tolerance tests need to have the standard
readjusted before a diagnosis is made. Such people
also require an understanding of potential differences in
normal levels on home blood glucose monitoring units
when they are regulating insulin at home.
Sources: Dissanayake, A. (2008). About Diabetes. New Zealand
Society for the Study of Diabetes (NZSSD).
education/diabetes.html; Australian Institute of Health andWelfare
(AIHW). (2013). Diabetes.
Cultural considerations
BOX 38.3
Managing glucose levels during stress
The body has many compensatory mechanisms for
ensuring that blood glucose levels stay within a safe
range.The sympathetic stress reaction elevates blood
glucose levels to provide ready energy for fight or
flight (see Chapter 29).The stress reaction causes the
breakdown of glycogen to release glucose and the
breakdown of fat and proteins to release other energy.
STRESS REACTIONS
The stress reaction elevates the blood glucose
concentration above the normal range. In severe stress
situations—such as an acute myocardial infarction or
a car crash—the blood glucose level can be very high
(above 8.0 mmol/L).The body uses that energy to fight
the insult or flee from the stressor.
Nurses and midwives in acute care situations need
to be aware of this reflex elevation in glucose when
caring for people in acute stress, especially people
in emergency situations whose medical history is
unknown.The usual medical response to a blood
glucose concentration of above 8.8 mmol/L would be
the administration of insulin. In many situations, that is
exactly what is done, especially if the person’s history
is not known and the effects of such a high glucose
level could cause severe systemic reactions. Insulin
administration causes a drop in the blood glucose level
as glucose enters cells to be either used for energy or
converted to glycogen for storage.
However, a problem may arise in the acute care
setting, particularly in a non-diabetic person. Relieving
the stress reaction can also drop glucose levels as the
stimulus to increase these levels is lost and the glucose
that was there is used for energy. A person in this
situation who has been treated with insulin is at risk for
development of potentially severe hypoglycaemia.The
body’s response to low glucose levels is a sympathetic
stress reaction, which again elevates the blood glucose
concentration. If treated, the person potentially can enter
a cycle of high and low glucose levels.
BEST CARE PRACTICE
Nurses and midwives are often the ones in closest
contact with the highly stressed person—in the
emergency room, the intensive care unit, the post-
anaesthesia room—and should be constantly aware of
the normal and reflex changes in blood glucose that
accompany stress. Careful monitoring, with awareness
of stress and the relief of stress, can prevent a prolonged
treatment program to maintain blood glucose levels
within the range of normal, a situation that is not
“normal” during a stress reaction.
Diabetic people who are in severe stress situations
require changes in their insulin doses.They should be
allowed some elevation of blood glucose, even though
their inability to produce sufficient insulin will make
it difficult for their cells to make effective use of the
increased glucose levels. It is a clinical challenge to
balance glucose levels with the needs of the person
because so many factors can affect the glucose level.
Source: American Diabetes Association (ADA). (2008). Standards of
medical care for patients with diabetes mellitus. Diabetes Care, 38,
S14–S36.
The evidence
BOX 38.4
