Insulin
What is insulin?
Insulin is an essential-for-life substance produced by
the pancreas, a gland behind the stomach.
Insulin enables glucose (sugar) from the bloodstream
to enter the body’s cells and be used for energy.
Insulin also stops the body from breaking down other
tissues such as fat and muscle.
The body normally produces a very low level of insulin
overnight and between meals. The body produces
a large boost when food is eaten, particularly
carbohydrate rich food.
Who needs to take insulin?
All people with type 1 diabetes need insulin around
the clock in order to stay alive, either administered by
multiple daily injections or through an insulin pump
attached to the body under the skin.
If the person uses an insulin pump, the cannula that
sits beneath the skin requires changing every few
days, in addition to the actual site on the body and
refilling of the insulin vial.
Many people with type 2 diabetes also need to take
one or more doses of insulin a day to manage their
blood glucose levels. They may use insulin alone, or
in combination with other oral or injectable diabetes
medications.
Some women with pregnancy related diabetes
(gestational diabetes) also need tablets (metformin)
and/or insulin to manage blood glucose levels.
There are many different types
of insulin
Insulin is usually of the same strength (100 IU/ml)
across products but comes in very different
preparations that differ by time of onset, peak
strength and duration.
In Australia, the most prescribed insulins are
currently:
» rapid acting insulins which last 2-4 hours
» flat profile longer acting insulins which either have
a 12-hour or 24-hour duration OR
» intermediate (time) acting insulins
» in addition, there are many pre-mixes of both the
rapid and intermediate insulins.
Many people with type 2 diabetes also use a
non-insulin form of injection that stimulates the
pancreas to produce insulin).
Caution:
Insulin requirements
• Glycaemia is the medical term referring
to the level of glucose in the blood.
• Reduced or missed doses of insulin,
stress, other illness or injury can lead to
dangerously high blood glucose levels
known as hyperglycaemia.
• If left untreated, hyperglycaemia can lead
to a potentially life-threatening condition
known as diabetic ketoacidosis or DKA.
• Too much insulin or insufficient food intake
can lead to dangerously low blood glucose
levels known as hypoglycaemia or hypos.
• If left untreated, hypoglycaemia can lead to
loss of consciousness, coma and/or death.
Caution:
Insulin switching
• If a person’s usual type of insulin is not
available, it is vital to seek medical advice
before substituting with a different type of
insulin.
• It is also vital to understand there is no
“standard” dose of insulin. A complex
number of factors and calculations
make up each individual’s unique
requirements. Such factors include
insulin sensitivity, carbohydrate to insulin
ratios and patterns of exertion/activity
over any given 24-hour period
If you’re just starting out with insulin, it can take a little getting used to. With a little practice, you’ll be a pro in no time.
Insulin is a naturally occurring hormone secreted by your pancreas. If you are prescribed insulin, it may be because your body doesn’t produce it (type 1 diabetes) or your body doesn’t use it properly (type 2 diabetes).
There are many different types of insulin sold in the United States, which differ in how they’re made, how they work in the body, and how much they cost. It’s also available in different strengths—most commonly, U-100. Your doctor will help you find the right type of insulin for your health needs.
When it comes to syringes, your doctor will advise on which capacity you need based on your insulin dose. In general, smaller capacity syringes can be easier to read and draw an accurate dose. Here are some tips:
If your largest dose is close to the syringe’s maximum capacity, consider buying the next size up in case your dosage changes
If you need to measure doses in half units, be sure to choose a syringe that has these markings
If you’re traveling outside of your country, be certain to match your insulin strength with the correct size syringe.
you’ll get to know three terms: onset, peak time and duration. The onset is how long it takes for the insulin to start lowering your blood sugar. The peak time is when it’s at its maximum strength, and duration is how long it continues to work.
Here’s a quick look at the different types of insulin. If you need a mix of two types, you can talk to your doctor about getting a premixed supply.
Rapid-acting insulin begins to work about 15 minutes after injection, peaks in about 1 hour, and continues to work for 2 to 4 hours
Regular or short-acting insulin usually reaches the bloodstream within 30 minutes after injection, peaks anywhere from 2 to 3 hours after injection, and is effective for approximately 3 to 6 hours
Intermediate-acting insulin generally reaches the bloodstream about 2 to 4 hours after injection, peaks 4 to 12 hours later, and is effective for about 12 to 18 hours
Long-acting insulin reaches the bloodstream several hours after injection and tends to lower glucose levels fairly evenly over a 24-hour period.
Insulin is a naturally occurring hormone secreted by the pancreas. Many people with diabetes are prescribed insulin, either because their bodies do not produce insulin (type 1 diabetes) or do not use insulin properly (type 2 diabetes).
There are more than 20 types of insulin sold in the United States. These insulins differ in how they are made, how they work in the body and how much they cost. Your doctor will help you find the right type of insulin for your health needs and your lifestyle.
There are different types of insulin depending on how quickly they work, when they peak and how long they last.
Insulin is available in different strengths; the most common is U-100.
All insulin available in the United States is manufactured in a laboratory, but animal insulin can still be imported for personal use.
Inside the pancreas, the hormone insulin is made in the beta cells, which are part of the Islets of Langerhans. These islets also have alpha cells, which make glucagon, as well as delta cells. With each meal, beta cells release insulin to help the body use or store the blood sugar it gets from food.
In the beta cells, insulin is created first as a big molecule called “proinsulin.” Proinsulin is broken into two pieces: insulin and C-peptide. C-peptide is important especially when determining treatment because it can be used to measure how much insulin a person is making. The more C-peptide a person has, the more insulin they are making. This can help a provider determine how much insulin to prescribe.
In people with type 1 diabetes, the pancreas no longer makes insulin. The beta cells have been destroyed and they need insulin shots 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 because it would be broken down during digestion just like the protein in food. It must be injected into the fat under your skin for it to get into your blood. In some rare cases insulin can lead to an allergic reaction at the injection site. Talk to your doctor if you believe you may be experiencing a reaction.
Types of insulin
Rapid-acting insulin, begins to work about 15 minutes after injection, peaks in about one or two hours after injection, and last between two to four hours. Types: insulin aspart (Fiasp, NovoLog) Insulin glulisine (Apidra), and insulin lispro (Admelog, Humalog, Lyumjev)
Regular or short-acting insulin usually reaches the bloodstream within 30 minutes after injection, peaks anywhere from two to three hours after injection, and is effective for approximately three to six hours. Types: Human Regular (Humulin R, Novolin R, Velosulin R)
Intermediate-acting insulin generally reaches the bloodstream about two to four hours after injection, peaks four to 12 hours later, and is effective for about 12 to 18 hours. Types: NPH (Humulin N, Novolin N, ReliOn)
Long-acting insulin reaches the bloodstream several hours after injection and tends to lower glucose levels up to 24 hours. Types: degludec (Tresiba), detemir (Levemir), and glargine (Basaglar, Lantus)
Ultra long-acting reaches the blood stream in six hours, does not peak, and lasts about 36 hours or longer. Types: glargine U-300 (Toujeo)
Premixed insulin can be helpful for people who have trouble drawing up insulin out of two bottles and reading the correct directions and dosages. It is also useful for those who have poor eyesight or dexterity and is convenient for people whose diabetes has been stabilized on this combination.
In 2015 an inhaled insulin product, Afrezza, became available in the U.S. Afrezza is a rapid-acting inhaled insulin that is administered at the beginning of each meal and can be used by adults with type 1 or type 2 diabetes. Afrezza is not a substitute for long-acting insulin. Afrezza must be used in combination with injectable long-acting insulin in patients with type 1 diabetes and in type 2 patients who use long-acting insulin.
Inhaled insulin begins working within 12 to 15 minutes, peaks by 30 minutes, and is out of your system in 180 minutes. Types: Technosphere insulin-inhalation system (Afrezza)
Characteristics of insulin
Insulin has three characteristics:
Onset is the length of time before insulin reaches the bloodstream and begins lowering blood sugar.
Peak time is the time during which insulin is at maximum strength in terms of lowering blood sugar.
Duration is how long insulin continues to lower blood glucose.
Insulin strength
All insulins come dissolved or suspended in liquids. The standard and most commonly used strength in the United States today is U-100, which means it has 100 units of insulin per milliliter of fluid, though U-500 insulin is available for patients who are extremely insulin resistant.
U-40, which has 40 units of insulin per milliliter of fluid, has generally been phased out around the world, but it is possible that it could still be found in some places (and U-40 insulin is still used in veterinary care).
Insulin is life—without it, the body can’t convert the food we eat
into the energy that’s needed to survive. Type 1 diabetes targets for
destruction the cells that make insulin, and so the disease absolutely
requires that insulin be taken as a medication. The relationship
between insulin and type 2 diabetes is more complicated. People
with type 2 can make some of their own insulin, but it’s not enough to
maintain blood glucose levels.
Type 2 diabetes can be treated with medication in several ways and
without question, insulin is the right option for certain people with type
2 diabetes.
1 Starting insulin does not mean you failed at caring for your diabetes
Some people see insulin use, or the need to start insulin, as a failure. It’s not. Type 2 diabetes is
a progressive illness, which means that over time the body makes less and less insulin. Even
people without diabetes produce less insulin as they age.
2. Insulin does not cause diabetes complications
Insulin helps bring blood glucose to target, which can prevent complications, not cause them.
The perception that insulin is related to diabetes complications may exist because insulin users
have usually had diabetes longer on average than those who take other medications. Having
diabetes for a long time, even when it is managed, makes some types of complications more
likely. Plus, doctors may tend to prescribe insulin for people who are having trouble managing
their blood glucose and high blood glucose levels also raises the risk for diabetes complications.
3. Insulin is not only for people who’ve had diabetes a long time
Sometimes insulin is the right choice for a person newly diagnosed with type 2 diabetes,
particularly if blood glucose levels are very high at diagnosis. After blood glucose levels are
better managed, it may be possible to reduce or stop insulin and use another type of diabetes medication.
4. Oral medications are not necessarily safer
It’s true that too much insulin can cause blood sugar to go too low (hypoglycemia), but it is
otherwise safe and has no adverse effects on the heart, kidneys, pancreas, or liver.
5. Injections don’t need to hurt
Insulin has to make its way under the skin to work, and for that you need a needle. Some
people may experience discomfort when injecting insulin. However, today’s insulin needles
are short and very thin—making injections less painful than they once were. If concerns about
pain are keeping you from trying insulin, talk to your doctor about testing a needle during a visit
or if inhalable insulin is right for you. You may be pleasantly surprised.
6. Insulin doesn’t necessarily lead to weight gain
Insulin helps the body absorb the calories from the foods you eat, so weight gain is a risk. When
starting insulin, you can take steps to avoid gaining weight. Talk to your diabetes care team
about steps you can take.
7. Insulin can cause hypoglycemia
The occasional low may be hard to avoid when taking insulin, but people with type 2 diabetes
who take only long-acting insulin are less likely to have hypoglycemia than those taking multiple
daily shots of mealtime insulin. It may be scary, but the unpleasant symptoms of low blood
sugar are your body telling you that your blood glucose is too low and you need to eat
something. Before you start a new exercise routine or change your eating plan or if you
experience lows, talk to your doctor about a dose adjustment.
8. Taking insulin may be easier than you think
You may associate insulin with carbohydrate counting, and other tasks. Some insulin users do
benefit from these activities, but not everyone will need to do the extra work. For example, most
people with type 2 diabetes who take insulin use a fixed dose of long-acting insulin, so they may
not need to count carbs, which is a strategy for adjusting mealtime insulin doses.
9. Syringes are not the only way to deliver insulin
There are other insulin delivery options available, such as pens and pumps. Many people who’ve
been drawing up insulin with vials and syringes for years find freedom in insulin pens. They’re
more portable, user friendly, discreet, easier to read, and use pen needles as tiny as 4 mm long.
That said, depending on insurance, they can cost more than vials of insulin. There are also insulin
pumps available. Talk to your diabetes team about what’s right for you.
10. Starting to use insulin doesn’t mean you’ll need to use it forever
Insulin has gotten a reputation for being an “end of the line” medication for type 2 that once
started, can’t be stopped. Once glucose levels are controlled and lifestyle changes are in place,
people may want or need to include other medications that could change how much they use or
the need to keep using insulin
