Insulin: types, effects, therapy and resistance of the diabetes hormone
Created: 12/06/2022, 3:00 p.m
By: Natalie Hull Drawbar
If the function and effect of insulin is disturbed, certain symptoms appear and diabetes can develop.
Which insulin therapy helps.
Insulin is a vital hormone for the human body and the only one that can lower blood sugar.
It ensures that the blood sugar level does not rise too high, especially after meals.
At the same time, it transports glucose (glucose as a naturally occurring carbohydrate) to the body's cells.
A disruption in insulin function and an increased or too low insulin level in the blood results in various symptoms and can lead to diseases such as diabetes.
Not only for people with diabetes it is worth knowing how important insulin is, how it works in our body, what influence it has on our blood sugar and how diabetes can develop.
contents
What is insulin?
Insulin secretion: what is the role of the hormone?
What is the effect of insulin?
What is a normal insulin level?
Blood sugar levels at a glance
Insulin resistance and its consequences
Insulin production: therapy for people with diabetes
Inject insulin: Conventional intensified insulin therapy
Types of insulin at a glance
Side effects of insulin therapy
What is insulin?
Insulin is a vital hormone and the only one that can lower blood sugar.
If its function is disturbed, diabetes can develop.
(Iconic image) © Science Photo Library/Imago
Insulin is an essential hormone produced in the pancreas, also known as the pancreas.
Next to the liver, the pancreas is one of the largest glands in the human body and is located behind the stomach between the spleen and the duodenum.
Insulin is produced in the beta cells of the so-called islets of Langerhans, the islet organ of the pancreas.
The name also derives from these islet gland cells: insulin comes from Latin and means “insula”, meaning “island”.
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The beta cells first produce the precursor proinsulin.
The proinsulin splits into an insulin molecule and a so-called C-peptide, both of which are released into the blood in the same proportion.
According to
Apotheken Umschau
, the C-peptide level in the blood can be used to determine whether the pancreas is still producing enough insulin - values below 0.2 μg/l indicate an insulin deficiency, which is the case with type 1 diabetes.
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Insulin secretion: What is the function of the hormone in the body?
Insulin has the important task of lowering the blood sugar level and keeping it within the normal range.
At the same time, insulin ensures that the glucose from the blood is absorbed by the cells for energy conversion.
Insulin is the only hormone that can lower blood sugar.
Insulin release, also known as insulin secretion, is stimulated by an increase in glucose, blood sugar, and to a lesser extent by free fatty acids, amino acids and hormones in the gastrointestinal tract.
Insulin is secreted in spurts, not evenly.
About every three to six minutes, the insulin-producing beta cells release the blood-sugar-lowering hormone into the blood.
In addition to the blood sugar-lowering function and the "intermediary role" between sugar and cell, insulin also influences the perception of appetite and hunger in the brain.
In addition, the hormone inhibits fat burning in order to regulate the glucose content during food intake and the rising blood sugar level.
If there is a lack of insulin, the body uses the fat cells to generate energy.
The result: free fatty acids flood the organism, which can result in acidification of the blood (ketoacidosis).
This severe metabolic imbalance is more likely to occur in type 1 diabetes and less so in type 2 diabetes.
What is the effect of insulin?
In practice, the hormonal control loop caused by insulin in the human body looks as follows:
The body absorbs food.
Food is converted into glucose, i.e. sugar, during digestion.
Depending on what you eat, the blood sugar level rises more or less.
There are foods that even lower blood sugar.
In response, the insulin-producing beta cells secrete the blood-sugar-lowering hormone insulin.
Only insulin can affect blood sugar levels.
Insulin now takes on the important task of transporting glucose from the blood through the cell wall into the interior of the cell.
To do this, insulin docks onto the insulin receptors on the cell surface.
Now the glucose can get from the blood to the inside of the cell like over a bridge.
This step also reduces the sugar content in the blood plasma.
The body's cells either convert glucose directly into energy or store it as glycogen in liver, muscle and kidney cells as well as in adipose tissue so that it can be made available at short notice when needed.
Only when there is an acute lack of energy does the body fall back on its glycogen stores and convert it into the necessary energy.
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It is the liver and muscle cells in particular that, thanks to insulin, can absorb and store large amounts of glucose.
Because they respond very well to the released insulin.
On the other hand, the nerve cells of the central nervous system (CNS) with the spinal cord and brain as well as nerve nodes (ganglia) absorb the sugar molecules, i.e. glucose, independently of the insulin release.
However, if the insulin-dependent cells show an increased need for glucose, the result can be an undersupply of sugar in the nerve cells.
Severe low blood sugar (hypoglycaemia), which can occur particularly with diabetes, affects the brain.
If the lack of insulin is not remedied by the administration of glucose - for example glucose, juice or sweetened drinks,
Hormonal antagonists to insulin
A certain amount of glucose in the blood is important for the human body to be able to function.
In healthy people, a natural protective mechanism with hormonal opponents such as glucagon, adrenaline and cortisone is triggered so that the blood sugar does not fall below a value of 80 mg/dl due to the released insulin.
These antagonists to insulin regulate the blood sugar back to a normal glucose value.
During this time, insulin production and secretion is greatly reduced.
What works without problems for most people is prone to malfunction in people with diabetes due to their “artificial” insulin therapy.
What is a normal insulin level, which blood sugar levels are normal?
The hormone insulin is the only chemical messenger in our body that regulates or lowers blood sugar.
The higher the blood sugar level, the more insulin is secreted and the more the insulin level in the blood rises to lower the blood sugar level.
The reference value for insulin is the C-peptide.
With its measurement in the blood, it can be assessed how much insulin the pancreas is still producing.
In a healthy person, a normal fasting value (at least 12 hours without food) is between 0.81 and 3.85 μg/l.
Values below 0.2 μg/l indicate an insulin deficiency.
According to the German Center for Diabetes
Research, factors such as hereditary factors, obesity and lack of exercise, insensitivity to insulin (insulin resistance), impaired insulin secretion and impaired production of certain intestinal hormones can cause insulin deficiency
.
People with type 2 diabetes often have an insulin level that is too high (hyperinsulinemia), since in this form of diabetes insulin is produced but it cannot affect the cells.
This is called insulin resistance.
Insulin levels that are too low are typical of type 1 diabetes and hypofunction of the pituitary gland (pituitary insufficiency).
If the insulin supply is disturbed, this can result in low or high blood sugar.
In the case of high blood sugar (hyperglycemia), the insulin value or the blood sugar value is above 7.8 mmol/l (140 mg/dl).
The reason is usually that insulin is missing or not working sufficiently.
The result is an elevated blood sugar level.
In the case of low blood sugar (hypoglycaemia), the blood sugar level is usually below 3.3 mmol/l (60 mg/dl).
Blood sugar levels at a glance
Blood sugar levels – i.e. the concentration of glucose in the blood – can be expressed in two units: “milligrams per deciliter” (mg/dl) or “millimoles per liter” (mmol/l).
Mmol/l is the most widely used unit internationally.
Normal blood glucose levels in healthy people:
Fasting -> less than 100 mg/dl (5.6 mmol/l)
Any time after a meal -> less than 140 mg/dl (7.8 mmol/l)
HbA1c -> between 4, 5 and 5.7 percent
Slightly elevated blood glucose levels in prediabetes:
Fasting -> between 100 and 125 mg/dl (5.6 to 6.9 mmol/l) Anytime
after a meal -> 140 to 199 mg/dl (7.8 to 11 mmol /l
/l)
HbA1c -> between 5.7 and 6.5 percent
Elevated blood glucose levels in people with diabetes:
Fasting -> 126 mg/dL (7.0 mmol/L) or higher
Any time after a meal -> above 200 mg/dL (11.1 mmol/L)
HbA1c -> higher than 6.5 percent
What are the symptoms when insulin levels are too high or too low?
An insulin level that is too high or a blood sugar level that is too low is particularly dangerous for the nervous system and brain, as it requires glucose as an energy source.
If there is a lack of sugar molecules, the body reacts with stress symptoms such as tachycardia, tremors and sweating.
Severe hypoglycaemia can even be life-threatening.
Diabetics are particularly affected by this, as
Netdoktor
says.
A drop in glucose in the body with low blood sugar is reflected in these symptoms:
fatigue
weakness
Tremble
Sweat
confusion
seizures
comatose state
A high blood sugar level or low insulin level in the blood can lead to the following symptoms:
fatigue
listlessness
dizziness
nausea
Strong thirst
Frequent urination
Insulin resistance: The result is hyperinsulinism, diabetes, obesity and high blood pressure
If cells no longer respond adequately to insulin, this is referred to as insulin resistance.
Then enough insulin can be released, but it cannot develop its effect on the cells.
Insulin resistance is indicated by the so-called Homa index, which is calculated from the concentration of insulin and glucose.
You should not eat for at least twelve hours before the measurement.
In the best case, the result should be below 2.5.
In type 2 diabetics, the average value is usually over 5.0.
Doctors assume that insulin resistance can be inherited.
Unhealthy, high-sugar diets and lack of exercise can promote insulin resistance.
People with insulin resistance have persistently high insulin levels in their blood, which can ultimately not only cause diabetes, but also obesity, high blood pressure and dyslipidemia.
Those affected who show all the accompanying symptoms then suffer from what is known as the metabolic syndrome.
Insulin production: therapy for people with diabetes
People with type 1 or type 2 diabetes usually need to be treated with insulin therapy.
Thanks to the two physicians Frederick Grant Banting and Charles Best, diabetics can now be treated well and symptoms alleviated with appropriate insulin preparations.
In 1921, the two of them succeeded in isolating the vital insulin from a dog's pancreas - the foundation stone for diabetes therapy was laid.
For insulin therapy, biosynthetically produced insulin is obtained in the laboratory, which is then injected into the body to replace the endogenous hormone that is missing.
In the early years of insulin therapy, insulin was derived from the pancreas of cattle and pigs.
Nowadays, only insulin from the pig's pancreas is used, since it corresponds more closely to the structure of human insulin.
Around 95 percent of insulin treatments in Germany are now based on genetically engineered human insulin, as its structure is identical to that of human insulin.
Injecting insulin: Conventional intensified insulin therapy for type 1 and type 2 diabetes
Patients with type 1 diabetes receive what is known as intensified conventional therapy (ICT):
Intensified conventional therapy (ICT) for type 1 diabetes
Inject long-acting insulin once or twice a day
Short-acting insulin can also be injected before meals to compensate for increases in blood sugar after meals or to correct temporarily elevated levels
The person concerned calculates the necessary insulin dose independently
Type 2 diabetes patients are usually prescribed conventional insulin therapy (CT) or intensified conventional therapy (ICT):
Conventional insulin therapy (CT) in type 2 diabetes
Inject a fixed dose of insulin before breakfast and dinner
Combination tablets can also lower blood sugar
Intensified conventional therapy (ICT) in type 2 diabetes
Depending on the amount of carbohydrates, inject a short-acting insulin with the meal, the dose of which the patient determines himself.
Long-acting insulin covers the daily basic requirement and is usually only injected once a day before the night.
Types of insulin: NPH insulin, human insulin, old insulin, regular insulin, long-acting insulin
Different types of insulin or combinations of them are used in insulin therapy.
There is long-acting insulin, so-called long-acting insulin or insulin delay, and fast-acting insulin:
Fast-acting insulin
Fast-acting insulin is used to correct blood sugar levels that are too high for a short time, especially around meals.
Compared to long-acting insulins, insulins with a rapid effect have the advantage that a rise in blood sugar after eating and hypoglycaemia as a result of insulin acting for too long can be avoided.
The blood sugar-lowering effect usually sets in after ten to 15 minutes.
If a very fast-acting insulin is injected, the effect can be felt after five minutes.
Regular insulin or old insulin
Regular insulin is a fast-acting insulin with no other additives and is usually genetically engineered.
Its effects set in within 15 to 20 minutes.
The maximum effect is reached after about two to three hours.
Normal insulin was the first insulin to treat diabetes and is therefore also called old insulin.
Human insulin and long-acting insulins
Long-acting insulins or human insulin are designed to mimic the natural activity of the pancreas independent of food.
In healthy people, the gland continuously releases small amounts of insulin into the blood to keep glucose levels stable.
The effects kick in after an hour or more and wear off after around 16 to 48 hours.
Long-acting insulins are usually injected once or twice a day.
The NPH insulin (Neutral Protamin Hagedorn) is a human insulin and long-term insulin or insulin delay, which develops its effect with a delay due to the addition of protamine - amino acids and peptides.
Side effects of insulin therapy: Allergy and obesity possible
Insulin is an endogenous hormone that can lead to side effects in humans as part of synthetic production and therapy.
In addition, the body can get used to the insulin, so that an ever higher dose is required.
Possible consequences are obesity and a higher risk of stroke and heart attack.
Therefore, insulin therapy for type 2 diabetes should only be started if alternative treatment approaches such as weight reduction and dietary changes do not bring the desired success.
Type 1 diabetes requires lifelong insulin therapy.
Patients who develop an insulin allergy react to the insulin preparations with symptoms such as rash, itching and swelling.
Sources
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https://www.ndr.de/ratgeber/gesundheit/Diabetes-Typ-2-Symptome-Urcause-und-treatment,diabetes196.html
https://www.netdoktor.de/symptome/hypoglycaemie-unterzuckerung/
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Prof. Dr. medical Werner A. Scherbaum, Director of the Clinic for Endocrinology, Diabetology and Rheumatology at the University Hospital Düsseldorf
https://www.gesundmed.de/laborwerte/insulin/
https://www.planet-wissen.de/gesellschaft/opathien/diabetes/pwiediediscovererdesinsulinsbantingundbest100.html#Team
https://www.bundesgesundheitsminister.de/themen/praevention/gesundheitsinstrumente/diabetes.html
This article only contains general information on the respective health topic and is therefore not intended for self-diagnosis, treatment or medication. In no way does it replace a visit to the doctor. Unfortunately, our editors are not allowed to answer individual questions about clinical pictures.
