WHAT IS
INSULIN?
Inside the pancreas, beta cells make the
hormone insulin. With each meal, beta cells release insulin to
help the body use or store the glucose it gets from food.
In people with type 1 diabetes, the
pancreas no longer makes insulin. The beta cells have been
destroyed. They need insulin shots or injections to use glucose
from meals.
People with type 2 diabetes make insulin,
but their bodies don't respond well to it. Some people with type
2 diabetes need diabetes pills or insulin shots to help their
bodies use glucose for energy.
Insulin cannot be taken as a pill. It would
be broken down during digestion just like the protein in food.
Insulin must be injected into the fat under your skin for it to
get into your blood.
There are more than 10 types of insulin
sold in Singapore. These insulins differ in how they are made,
how they work in the body, and price. Insulin is made in labs to
be identical to human insulin.
There are four main types of insulin, based
on
· how soon the insulin starts working
(onset)
· when it works the hardest (peak time)
· how long it lasts in your body (duration)
However, each person responds to insulin in
his or her own way. That is why onset, peak time, and duration
are given as ranges.
Rapid-acting
insulin (Lispro or Humalog) reaches the blood within
10 to 15 minutes after injection. It peaks 30 to 90 minutes
later and may last as long as 5 hours.
Short-acting
(regular) insulin eg. Actrapid usually reaches the
blood within 30 minutes after injection. It peaks 2 to 4 hours
later and stays in the blood for about 4 to 8 hours.
Intermediate-acting (NPH and lente) insulins eg.
Insulatard or Monotard reach the blood 2 to 6 hours after
injection. They peak 4 to 14 hours later and stay in the blood
for about 14 to 20 hours.
Long-acting (ultralente)
insulin eg Ultratard takes 6 to 14 hours to start
working. It has no peak or a very small peak 10 to 16 hours
after injection. It stays in the blood between 20 and 24 hours.
Insulin glargine
(Lantus) is a new long acting insulin with no peak. It is
usually given once a day. Insulin detemir (Levemir) is another
long-acting insulin analogue that does not have a distinct
action peak.
Some insulins come mixed together eg
Mixtard or Novomix or Humalog Mix 25. For example, you can buy
regular and NPH insulins already mixed in one bottle. They make
it easier to inject two kinds of insulin at the same time.
However, you can't adjust the amount of one insulin without also
changing how much you get of the other insulin. The proportions
are fixed and cannot be altered.
Additives.
All insulins have added ingredients to keep them fresh and help
them work better. Intermediate- and long-acting insulins also
have ingredients to make them act longer. Today's insulins are
very pure. Allergic reactions are very rare.
Storage and safety.
Using cold insulin can make your shot more painful. You can keep
the bottle of insulin you are currently using at room
temperature or warm the bottle by gently rolling it between your
hands before you fill the syringe. If you buy more than one
bottle of insulin at a time, store the extra bottles in the
refrigerator until you start to use them. Never store insulin at
very cold (under 36 degrees Fahrenheit) or very hot (over 86
degrees Fahrenheit) temperatures. Extreme temperatures destroy
insulin. Do not put your insulin in the freezer or in direct
sunlight. Insulin may lose some potency if the bottle has been
opened for more than 30 days. Look at the bottle closely to make
sure the insulin looks normal. If you use regular, it should be
perfectly clear--no floating pieces or color. If you use NPH or
lente, it should be cloudy, with no floating pieces or crystals
on the bottle. Do not use insulin past the expiration date.
Insulin
Therapy
With the help of your endocrinologist, you
can find an insulin routine that will keep your blood sugar near
normal, help you feel good, and fit your lifestyle.
People diagnosed with type 1 diabetes
usually start with two injections of insulin per day of two
different types of insulin. People with type 1 diabetes
generally progress to three or four injections per day of
insulin of different types. The types of insulin used depend on
their blood sugar levels. Studies have shown that three or four
injections a day give the best blood sugar control and can
prevent or delay the eye, kidney, and nerve damage caused by
diabetes.
Most people with type 2 diabetes may need a
single injection of insulin in the evening (at supper or
bedtime) along with diabetes pills. Sometimes diabetes pills
stop working, and people with type 2 diabetes will start with
two injections per day. They may progress to three injections
per day.
Self-monitoring.
Checking your blood sugar and looking over results can help you
understand how exercise, an exciting event, or different foods
affect your blood sugar level. You can use it to predict and
avoid low or high blood sugar levels. You can also use this
information to make decisions about your insulin dose, food, and
activity.
Site rotation.
The place on your body where you inject insulin affects your
blood sugar level. Insulin enters the blood at different speeds
when injected at different sites. Insulin shots work best and
fastest when given in the abdomen. Insulin arrives in the blood
a little more slowly from the upper arms and even more slowly
from the thighs and buttocks.
Injecting insulin in the same general area
(for example, your abdomen) will give you the best results from
your insulin. This is because the insulin will reach the blood
with about the same speed with each shot. Don't inject in
exactly the same place each time but move around the same area.
Each meal-time injection of insulin should be given in the same
general area for best results. For example, giving your
before-breakfast injection in the abdomen and your before-supper
injection in the leg each day give more similar blood sugar
results. If you inject near the same place each time, hard lumps
or extra fatty deposits may develop. Both of these problems are
unsightly and make the insulin action less reliable. Ask your
doctor if you aren't sure where to inject your insulin.
Timing.
Insulin shots are most effective when you take them so that
insulin goes to work when glucose from your food starts to enter
your blood. For example, regular insulin works best if you take
it 20 to 30 minutes before you eat.
Too much or not
enough insulin?
High morning blood sugar levels before
breakfast can be a puzzle. If you haven't eaten, why did your
blood sugar level go up? There are two common reasons for high
before-breakfast blood sugar levels. One relates to hormones
that are released in the early part of sleep (called the Dawn
Phenomenon). The other is from taking too little insulin in
the evening. To see which one is the cause, set your alarm to
self-monitor around 2 or 3 a.m. for several nights and discuss
the results with your doctor.
Is insulin
dangerous or bad for me?
Insulin is not bad for you. Your
endocrinologist will have very good reasons for recommending it
for you. It is never used frivolously. It is used for a good
purpose. Instead of harming you, it will help you regain your
health, and protect you from serious diabetes complications
(like blindness and kidney failure) that arise from poor glucose
readings. Patients are also sometimes fearful that prolonged use
is bad. This is also absolutely not true. Children with type 1
diabetes have no choice but to use insulin. They grow up and
live to their 70s and 80s. They use insulin for 50 to 60 years,
and remain well. Without insulin, they would not even live. Do
not worry. Use insulin properly and with care, and it will serve
you well.
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