Wooa, this is some mind blowing stuff. Type 2 diabetes upon type 1 diabetes. Can this be real? Can someone with with type 1 diabetes develop type 2 diabetes also? Surely you are either type 2 or type 1 right?
I’m here to tell you this is a real thing. To explain how this happens we need to look at the pathophysiology of each disease (how they come about). I’ve done this a few times in several other blogs including what is type 1 and what is type 2 which you can find by clicking on the words.
Type 1 diabetes is the inability to produce your own insulin. An autoimmune response destroys your insulin producing cells in the pancreas. As a result, you cannot control your glucose levels. Your own immune system destroys the insulin producing cells in your pancreas.
Without insulin, your glucose levels will continue to rise. Before the invention of insulin, this condition was fatal.
This is a metabolic disease. In type 2 diabetes you can still produce insulin but it doesn’t work as efficiently. Insulin tells glucose to exit the blood and enter the cells where it can be used or stored as energy.
This message is hindered in type 2 diabetes. So less glucose can enter the cells and so it remains in the blood. We call this insulin resistance.
As a result, glucose levels rise above normal levels but in most instances there is still enough insulin working properly to prevent fatal occurrences. As time goes by the insulin becomes less and less efficient and the pancreas produces less insulin. In other words the pancreas gets tired. This is why people with type 2 usually end up on insulin.
The reasons for developing type 2 are primarily carrying too much weight (internally, externally or both, being unfit, age and genetics).
Why may this be a problem in type 1?
Lifestyle related causes are the main cause of type 2 diabetes. Up to 90% of people diagnosed with type 2 are overweight and/or unfit. Genetics and age also play a part. Regardless of the cause, type 2 diabetes effects metabolism of glucose and therefore is a metabolic disease.
In type 1s, insulin is injected to replace the lost insulin produced in the pancreas. Once injected, that insulin behaves in a similar way to naturally produced insulin. So if you have the same metabolic problems as someone with type 2 your injected insulin may not work as efficiently as it should.
Remember, type 1 is an autoimmune disease and type 2 is a metabolic disease. These are two different systems. Therefore, you can develop both regardless of whether you already have one or other.
If you are overweight, unfit, elderly or have a genetic predisposition to developing type 2 you may very well develop insulin resistance. This is regardless of whether you already have type 1 diabetes.
How is this treated?
Metformin is usually the first line drug used in type 2 diabetes. Therefore, type 1s with insulin resistance will usually be offered Metformin.
Metformin works in several ways but it has two primary mechanisms that can be helpful if you develop insulin resistance.
It slows down the amount of glucose being released from the liver. This helps reduce the amount of excess glucose exiting the liver and into the blood.
Second, and importantly, Metformin helps re-sensitise the cells to insulins message so it can work more efficiently. So you need less insulin to get the same amount of glucose into the cells.
Type 1’s on Metformin
Metformin is certainly prescribed in more type 1 patients that I see. If this happened to you, you will still be classified as type 1. However, it has become evident that you have developed some insulin resistance for any of the aforementioned reasons.
Untreated, it is likely your insulin doses will become very large with little benefit.
In practice most practitioners will not mention to you type 2 upon type 1 and likely just offer Metformin to help glucose levels. This will be one additional medication to add to the repertoire. However, hopefully with this new information you may now understand why.
Is there anything I can do about?
Well there’s not much you can do about age or genetics. BUT if you are overweight or inactive then these are great places to start.
Type 1s with insulin resistance will benefit just as much as type 2’s from lifestyle changes from a metabolic perspective.
I do see quite a few patients who pull the genetics card despite being overweight or inactive. It may very well be genetics. However, my point of view is if you think it is genetics but you are overweight or unfit why not eliminate both these as causes and make some dietary changes and exercise more. Then if the condition doesn’t improve after this you can safely say it’s due to genetics.
It doesn’t take much additional weight before falling into the overweight or obesity categories. Often we think of obese people who are excessively fat. Obesity though is classified on a scale with 3 sub scales within the classification. People with obesity class 1 likely won’t appear grossly overweight despite technically being obese.
When lifestyle changes will not help in type 2 upon type 1
I’ve already mentioned there’s not much you can do about age or genetics. Often, these go hand in hand as those genetically susceptible to type 2 diabetes do not develop it into old age. Usually this can be modestly managed. You may not even notice this if you are type 1 taking insulin.
If you recognise yourself as being overweight and/or unfit making lifestyle changes will help.
This won’t compensate though for mismanaging your insulin. Lifestyle changes will only help if you are giving the correct does of background and rapid acting insulin. If there is an imbalance in your insulin doses, your glucose levels will remain high.
Therefore, the first port of call with any type 1 is to get the insulin doses correct and go from there.