The Causes Of Diabetes Type 1.
This is what used to be known, prior to 1997, as insulin-dependent diabetes mellitus (IDDM), juvenile diabetes, juvenile-onset diabetes, and ketosis-prone diabetes.
As usual, you may read down or use the links below to jump to the part of the page you need.
Information on Environmental Triggers.
1. Viral or Bacterial Infections.
2. Chemical toxins found in food and water.
3. Cow's Milk.
4. Stress.
Type of Type 1 Diabetes.
Type 1A, or Immune Mediated Diabetes.
Type 1B diabetes, or Idiopathic Diabetes Mellitus.
Subtype of Type1B, or Nonautoimmune Fulminant Type 1 Diabetes.
Prevention.
It seems that this type of diabetes comes on very suddenly, sometimes in a matter of days. In actual fact it is possible for it to have been around for years. The beta cells of the pancreas can be slowly destroyed over a period of time and it is only when around 80% of them are no longer working that hyperglycemia shows up.
Generally the older you are the longer it takes to manifest itself as full blown diabetes. In young children it can happen very quickly.
At one time this type of diabetes was thought to have no hereditary genetic connections because around 85% of the folk who developed it appeared to do so spontaneously. There was no sign of the disease in their immediate family. However that did leave the 15% who did not fit the rule.
Likewise when studies were done on identical twins, who share exactly the same genes, it was found that sometimes one had diabetes but not the other. If it was genetic both should have had it.
However, consider these stats:-
1. If there is no diabetes in your immediate family then the risk of getting diabetes is around 0.3 - 0.5%.
2. If one of your parents has diabetes the chances of your getting it rise to 2 - 6%
Strangely enough the risk is less if it is your mother who has the disease, around 3%, than if it is your father, where it becomes around 6%
3. If both your parents have diabetes then your chances of getting it are a whopping 20% - 30%.
4. If you have a brother or sister with diabetes the chance of your getting it too is 5%.
5. If your non-identical twin has Type 1 diabetes, you have a 20% risk.
6. If your identical twin has Type 1 diabetes, you have a 30 - 50% risk. The risk is even higher if the disease appeared before the age of 5. However if your twin only got the disease after the age of 25 the chance of you developing it is substantially lower.
One has to conclude from these facts that there is some sort of hereditary genetic connection, more a susceptibility to diabetes than an actual cause of it. And in fact scientists have identified some inherited genes that put people at a greater risk of getting Type 1 diabetes.
The genes in question are the human leukocyte antigen (HLA) genes. The job of these is to differentiate between 'own' and 'foreign' cells.
There are a whole collection of HLA genes in the system and not all contribute to the predisposition towards diabetes. However if we happen to inherit just the right combination from our parents we will be at greater risk.
For the genetically inclined the website Genetics.Com explains this situation very clearly.
But it is also obvious from the above facts that it cannot be heredity alone that causes folk to develop diabetes, or the numbers would read 100%, not 5%, or even 20%.
So we need to look even further for the cause. There must be some sort of 'trigger', some non-genetic factor, that sets the diabetic process in motion in genetically prone individuals.
Researchers are looking into an interaction between genes and environmental factors. Various environmental triggers have been suggested - note, I said suggested. There have been studies done that indicate a possibility, sometimes a high one, of these factors being involved but more needs to be done before they can say for sure.
Information on Environmental Triggers:-
1. Viral or Bacterial Infections.
One of the things that have made viruses suspect is the fact that there appears to be a seasonal variation in the diagnosis of Type 1 diabetes - it increases in the late autumn and early winter, at just the time when viral infections are at their greatest.
However not everyone agrees with this as they feel that the autoimmune process leading to diabetes is quite a long one and could have been triggered at any time.
During a viral infection antibodies against the virus are produced. As the virus infects the cells the antibodies target those cells and destroy them. Therefor a virus, like those of the Coxsackie group of viruses, that may infects the beta cells of the pancreas, will result in the destruction of those cells and the subsequent development of diabetes.
There may be an even more complex effect of the Coxsackie B4 virus. It has been found to be, in some respects, structurally similar to GAD (glutamic acid decarboxylase) which is an enzyme found on the surface of the beta cells. The immune system, in attempting to destroy the virus is confused by the similarities and turns on the beta cells as well.
It is thought that some viruses can cause changes in the beta cells that produce insulin. These changes will make those cells appear as 'foreign' to the body's immune system, which will then set about destroying them. Once enough have been destroyed to cause a dearth of insulin, diabetes will develop.
A number of different virus have been suggested as being implicated in triggering diabetes but not everyone is in agreement about them. They are mumps, rubella, measles, influenza, polio, cytomegalovirus, Coxsackie and Epstein-Barr virus.
The first three are of particular interest because both the individual vaccines and the combined MMR (measles, mumps and rubella) vaccines uses live viruses to produce their immunity.
However, as usual, there is little agreement within the scientific fraternity on whether these trigger diabetes or not.
Check out the following websites if you are interested in this issue:-
Childhood Vaccinations and Juvenile-Onset (Type-1) Diabetes.
MMR vaccination and Type 1 diabetes.
Current Evidence - No Link Between Vaccination and Type 1 Diabetes Mellitus.
Immunisation And Diabetes.
2. Chemical Toxins found in food and water.
Of particular interest here are nitrosamines. These are found in most cured meats (ham, salami, sausages, bacon etc) because meat itself contains amines and the sodium nitrate that is added to the cured meat as a preservative combines with the amines to form nitrosamines.
This process is aggravated by high temperatures and that is why nitrosamines are increased in fried bacon. Fortunately they have now found that ascorbic acid prevents this action from taking place and so it, or a derivative, is now usually added.
Nitrosamines can also be found in high levels in drinking water, especially in rural areas, as they are the chemical breakdown products of nitrates, and get into the water as a result of run off from nitrogenous fertilisers.
See - Research links child diabetes to nitrates.
3. Cow's Milk.
The evidence that this may be a trigger is mounting. It is the exposure of very young babies to cows milk, or formulas made from this, that seems to be the problem. Some of the large protein molecules in the milk appear to stimulate antibodies to the pancreas, causing an autoimmune reaction.
It is thought that very young, genetically susceptible, infants may have an immature immune system that just cannot cope with these whole protein molecules.
If the protein molecules are broken down (hydrolysed) into smaller pieces then the chances of this reaction occurring is greatly reduced.
It has been found that type 1 diabetes is less common in children who have been breast fed for longer periods so if you are pregnant and feel your child may be genetically predisposed to diabetes it may be worth considering breast feeding for the frist 8 months. If that is not possible then at the least make sure your formula is made with hydrolysed milk.
Examples of these are:-
Carnation Good Start from Nestle, which has partially hydolysed proteins or if you want to take it a step further there are Enfamil Nutramigen LIPIL from Mead Johnson Nutritionals and Alimentum Advance from Abbott Laboratories which are extensively hydrolysed.
HS International Ltd., UK makes Neocate which is a completely predigested formula.
Most of these products are sold for the use of babies who have allergies to milk proteins - avoiding diabetes is not mentioned, which is not surprising seeing that this trigger is still under investigation.
However if it were my child I would definitely use one of these formulas - they will not harm and might well help. They are unfortunately a little more expensive than the normal formulas (but not more than lifelong diabetes).
See websites below:-
Nestle
Good Start.
Ross.com Similac® Alimentum® Advance®.
The Neocate range and Food Allergy.
MeadJohnson.com Nutramigen® LIPIL®
There are 4 varieties of casein protein found in milk but it is only the A1 beta-casein that has been implicated in Type 1 diabetes.
Different cow's produce different amounts of these proteins. For instance Frisian-Holstein cows produce almost 80% A1 beta-casein milk while Jersey and Guernsey cows are mostly A2 beta-casein.
One must remember that the milk we buy is usually a mixture from different breeds of cows. It is possible in some places to buy particular breed milk and there are campaigns going on to get proper labelling stating what casein is present in the milk.
For further information see:-
Cows' Milk, Diabetes Connection Bolstered.
MILK - Questions and Answers on ‘A1’ and ‘A2’
4. Stress.
Stress can be either physical, for instance that caused by an accident or an illness, or mental, like acute anxiety or reaction to a something like the death of a parent.
Stress releases 'stress hormones', such as adrenaline and glucocorticoids, which counteract the effects of insulin, causing glucose levels to rise.
Stress may show up the previously unnoticed deficient insulin production of a pancreas. It has slowly had it's beta cells destroyed to the point where it now cannot make enough insulin to counter a dramatic rise in blood glucose resulting from the stress - a case of the body being 'pushed over the edge' so to speak..
It has been postulated that a sudden shock may trigger the immune system into an autoimmune response resulting in beta cell destruction. This may occur a long time before the diabetes is actually diagnosed.
So I would say we need to consider three things when looking for a cause of Type 1 diabetes.
1. Genetic susceptibility.
2. A trigger of some sort.
3. Autoantibodies - these are not totally definitive but are found in 85-90% of Type1 diabetics .
Type of Type 1 Diabetes.
(no, this is not a result of 'finger trouble!)
If you studied the table at the beginning of this article you will have noticed that there is now a separation within Type 1 diabetes, into immune mediated diabetes, sometimes called Type 1A diabetes and idiopathic diabetes or Type 1B. Lets look at Type 1A one first.
Type 1A
also known as Immune Mediated Diabetes, is the result of an autoimmune response - so what do I mean by that?
Well lets use an analogy. Think of your body as an old time castle. Everyone in that castle has their own position and purpose and each person is known to the rest and accepted as having a right to be there - all is happiness. However, suddenly strangers start appearing in their midst, sowing seeds of discontent. What happens? Well the lord of the castle( lets liken him to the brain) starts marshalling his loyal troops (the immune system) and they come along and evict the strangers, killing them if they offer to much resistance, until normality is restored.
Your body has the mechanisms in place to get rid of it's own invaders. If it did not we would never survive all the foreign substances that enter eg. bacteria and viruses.
But things can go wrong. What if the lord becomes a tad loopy and suddenly starts seeing invaders around every corner, no longer being able to tell friend from foe? He then orders his loyal troops to attack and kill the people who actually have a right to be there.
That is what happens in an autoimmune response. The body turns on itself and orders the immune system to destroy it's own cells, which it now sees as 'foreign'.
In Type 1A diabetes it is the beta cells of the pancreas that are attacked and destroyed, resulting in an ever decreasing amount of insulin being produced until there is no longer enough to control the elevated glucose levels and diabetes is diagnosed.
How do we know if it is type 1A?
We look for antibodies. Antibodies are proteins that the body produces to protect itself against foreign invaders. However in autoimmune disease these antibodies are faulty and begin attacking the bodies own cells. They are now termed autoantibodies.
The main ones that have been found in around 85-90% of newly diagnosed Type 1 diabetics are islet cell autoantibodies, though there are others as well.
It is the presence of these autoantibodies that classifies the disease as Type 1A.
The three most important antibodies that are usually looked for are:-
1. IAA - antiinsulin antibodies
2. GAD65 - anti-glutamic acid decarboxylase
3. ICA512 - a specific islet cell antibody
Sometimes the following two are also included in the assay as people with high levels of autoantibodies tend to have other autoimmune disease as well:-
1. IgA anti-endomysium antibodies (AEA) - these are tested for because they are a sign of celiac syndrome, which is another autoimmune disease found in 3-8% of newly diagnosed Type 1 diabetics.
2. Anti 21-hydroxylase - a diagnostic marker for Addison's disease, also an autoimmune disease found in 2% of newly diagnosed Type 1 diabetics.
Type 1B Diabetes
also known as Idiopathic Diabetes Mellitus, is a condition where the destruction of the pancreatic beta cells is caused by something other than an autoimmune process.
Not very much is known about this uncommon form of Type 1 diabetes and we definitely do not know the cause. It has been suggested that maybe the cells were damaged by a viral infection.
So what do we know?
1. It is found mainly in people of African, Asian and occasionally Hispanic origin.
2. It is definitely an inherited disease but is not associated with the HLA genes.
3. There is no evidence of any autoimmune process.
4. There is permanent pancreatic damage.
5. Patients are prone to ketoacidosis.
6. Their need for insulin comes and goes.
And then, believe it or not, there is a Subtype of Type 1B
called Nonautoimmune Fulminant Type 1 Diabetes. This was first observed in Japanese patients.
The disease had the following symptoms:-
1. Exceedingly rapid onset, sometimes as little as 4 days from first symptom to diagnosis .
2.HbA1c was almost normal (which is in line with the swift onset).
3.There was severe beta cell destruction.
4. The were no autoantibodies present.
5.There was pancreatic exocrine damage (that is damage to the non-insulin producing cells of the pancreas).
6. Pancreatic enzyme levels (of amylase and elastase ) were raised but there were no signs of pancreatitis.
7. Hyperglycemia was sever at diagnosis, in the region of 43mmol/L (774mg/dL)
Prevention.
One of the main reasons so much effort has been put into finding the cause of Type 1 diabetes is so that some way can be found of preventing it.
Those looking at preventative measures see two different ways of approaching them - either prevention prior to diagnosis, called primary prevention, or after diagnosis but before it has developed into a serious situation, called secondary prevention.
Screening for islet cell antibodies in people with a genetic susceptibility can give an indication of how high the persons chance is of developing Type 1 diabetes.
It may be worthwhile to vaccinate these people against the viruses that are seen as possible triggers or give them antiviral medication.
Some folk would say that it would be better NOT to vaccinate at all, - it all depends on your point of view.
Then there is the option of using cytotoxic drugs, such as those used in cancer treatment. The idea here is to destroy the cells which are attacking the beta cells, hopefully delaying the onset of diabetes.
However one would have to weigh up the side effects of the drugs (which are not good) and consider the fact that as yet they have found no way to stop them attacking normal cells along with the faulty ones.
Sometimes steroid drugs are used to treat autoimmune diseases and, as this is what type 1 is, they may help. However they too have harmful side effects, even to inducing diabetes itself (see steroid diabetes). They have also been known to stunt growth and as such would be unable to be used in children, who are the main ones at risk of developing Type 1 diabetes.
There have been studies done to see if taking Nicotinamide, one of the B group vitamins, would help protect the beta cells in susceptible people. There is some evidence to show that it actually does work but nothing conclusive as yet.
In 1993 a study, known as the Diabetes Control and Complications Trial (DCCT) was done, which dealt with the prevention of diabetes and it's complications. This showed that keeping ones blood glucose tightly under control, in fact as close to normal as possible, prevented the chance of diabetics getting complications.
I have to say here that I wonder what took them so long to come up with this choice piece of information when Dr Richard Bernstein had been trying to tell them just that from the 1970's onward. See Dr. Bernstein's Diabetes Solution.
At the moment a Diabetes Prevention Trial (DPT) is underway in the US. It is a study that is attempting to find out if low doses of insulin can stave off diabetes in people with a family history of the disease. The idea behind it is that taking external insulin may make the immune system less sensitive to the beta cells and therefore less inclined to destroy them.
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