Type 1 diabetes mellitus

Author: Dr Sorin Ioacara | Last update: November 9th, 2020

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Discover here: T1DM Definition | Type 1 vs Type 2 | Is type 1 worse? | Risk of appearance | T1DM causes | T1DM symptoms | T1DM stages | Diabetic ketoacidosis

Type 1 diabetes is not as complicated as it seems at first glance. The nowadays much easier access to science and technology can ensure a long and hassle-free life. Below we will see step by step what to do in this regard. So let’s start with a better understanding of what type 1 diabetes is and why it can be so dangerous.

Further, we will try to see what are the differences between the two classic forms of diabetes. Of course, the next question that arises is which of them is more dangerous. You will find there not only my conclusion, but also the arguments in question. In this way, you have the opportunity to make an opinion on this subject yourself, which may be different from the conclusion proposed by me.

Next, let’s find out how common type 1 diabetes is. Some say that diet can modify the risk of type 1 diabetes. Is that true? As a result, we dedicated an individual chapter to the analysis of the causes of type 1 diabetes. Here, you will also discover the mechanisms of pancreatic beta cells destruction.

Everyone should know the symptoms of diabetes in children. This topic is vital for the community. As a consequence, the section dedicated to symptoms of type 1 diabetes is one of the largest on this website.

The next lesson is about the stages of diabetes development. Knowing them means early diagnosis. Consequently, you’ll have the chance to reduce the risk of diabetic ketoacidosis at the later clinical onset.

Type 1 diabetes definition

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Type 1 diabetes is a disease of the endocrine pancreas characterized by a severe insulin secretion deficiency. This deficiency is due to the destruction of the pancreatic beta cells. Total lack of blood insulin is not compatible with long-term survival. As a result, the first thing a type 1 diabetes patient needs is multiple daily insulin injections. However, it is preferable to use an insulin pump where access is available.

The second thing a patient with type 1 diabetes needs after starting the insulin treatment is a continuous blood glucose monitoring sensor.

Why is type 1 diabetes dangerous?

Before the insulin discovery, all patients with type 1 diabetes died from diabetic ketoacidosis. Nowadays, the same thing can happen in the absence of insulin access. After the discovery of insulin, the onset of type 1 diabetes was no longer synonymous with a death sentence. On the contrary, long-term survival has become very feasible. However, doctors observed quite quickly that these patients had an increasingly poor quality of life.

The reason for the quality of life decrease in type 1 diabetes patients is, of course, the development of chronic complications. Loss of vision, amputations, chronic kidney disease leading to dialysis are just a few of them. These complications do appear if metabolic control over the years is not perfect.

Type 1 diabetes can be very dangerous if you don’t follow all the medical recommendations. But for those of you complying with doctor’s orders, the situation is not that dire nowadays. Carefully read the information on this site, listen to your GP (family doctor), make full use of the new diabetes technology options, and everything will be fine.

What is the difference between type 1 and type 2 diabetes?

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The main difference between type 1 and 2 diabetes consists of treatment indication. Second, treatment options diversity differs. On the third place is the reason and the moment of insulin initiation. The top ten most prominent differences between type 1 and type 2 diabetes are the following:

  1. Treatment options
  2. Treatment indication
  3. Insulin treatment
  4. How frequent it is
  5. Risk factors
  6. Symptoms evolution
  7. Why is blood sugar rising?
  8. The risk of ketoacidosis
  9. Prevention
  10. Cure

Treatment options and insulin indication

In terms of treatment options, their number is significantly higher in type 2 diabetes. Oral antidiabetics are the core long-term medication for type 2 diabetes. Totaly opposite, in type 1 diabetes, we exceptionally use them and only as an adjunctive medication.

The indication to follow the recommended treatment is for immediate survival in type 1 diabetes. On the contrary, in type 2 diabetes, the patient can survive for a long time without following the recommended treatment.

Doctors prescribe insulin in type 1 diabetes to ensure the survival of their patients. In type 2 diabetes, metabolic control is the reason for insulin prescription. The type 2 diabetes patient’s blood glucose levels would be uncontrolled without the needed insulin. Still, but life would not be in immediate danger. The type 2 diabetes patient can survive for a rather long time with blood glucose levels around 200 mg/dl (11 mmol/l).

In type 1 diabetes, all patients receive insulin from the time of clinical onset with persistent hyperglycemia. In type 2 diabetes, even though some may temporarily receive insulin at the time of diagnosis, most will initiate insulin late in the course of the disease. Usually, there are many years of treatment with other therapeutic options besides insulin until its use.

How frequent it is

At the whole population level, type 1 diabetes accounts for about 10% of all diabetes cases of all ages. As a result, type 2 diabetes is more commonly seen compared to type 1 diabetes. However, if we analyze only the population under the age of 25 years old, we will find that here, type 1 diabetes represents 90% of the cases. The conclusion would be that in children and young people, type 1 diabetes is more frequent compared to type 2 diabetes.

Inevitably, above 50 years, the percentage of type 2 diabetes gradually exceeds 90-95% of the total cases. At older ages, type 1 diabetes becomes increasingly difficult to discern within the “ocean” of type 2 diabetes cases.

Risk factors and symptoms evolution

The elements of the modern, western lifestyle have a relatively small impact on the risk of developing type 1 diabetes. In contrast, their impact is high for type 2 diabetes. The main culprits here are obesity and sedentary lifestyle.

Symptoms of hyperglycemia have an accelerated evolution in type 1 diabetes. Here, new traits appear daily. The existing ones are getting worse during 1-2 weeks. Slower progression, for more than a month, is the exception, not the rule.

In contrast, minor symptoms may persist for several years in type 2 diabetes. It may take up to ten years until the mild or medium symptoms will start disturbing the patient sufficiently enough to send him to the doctor. Rapid evolution over a few days or weeks is the exception, not the rule, in type 2 diabetes.

Why is blood sugar rising?

In type 1 diabetes, blood sugar increases as a result of the fall in insulin blood levels. In the fourth stage of type 1 diabetes, the immune system destroys 99,99% of the insulin-secreting pancreatic beta cells. As a consequence, the blood insulin concentration becomes drops to less than 1% of normal. Blood glucose values increase in this case as a direct consequence of the absolute lack of insulin.

On the contrary, in type 2 diabetes, the blood insulin concentration remains similar to that of individuals without diabetes. At least 10% of pancreatic beta cells survive after ten years of diabetes.

In type 2 diabetes, the essence of the problem is the body’s high demand for insulin. There can be a more than five times increase in insulin demand compared with an individual without diabetes. Blood glucose values increase in this situation because of the discrepancy between the high demand and limited supply.

The risk of ketoacidosis

Stopping treatment in type 1 diabetes is equivalent to a 100% risk of developing ketoacidosis. This complication usually appears after a time interval that varies from 12 to 72h. It all depends on the individual characteristics of the patient.

Stopping oral antidiabetic treatment in type 2 diabetes is associated with a negligible risk of ketoacidosis. Also, stopping insulin may not necessarily induce ketoacidosis if there is enough residual insulin secretion.

Glycemia may increase well above 500 mg/dl (27.8 mmol/l) in this case. However, ketoacidosis may be lacking. The persistence of a minimal blood insulin concentration that blocks the production of ketone bodies in the liver is the explanation for this phenomenon.


Unfortunately, in type 1 diabetes, there are currently no effective measures to prevent it. Combating sedentary lifestyle and obesity has some benefits, but the magnitude is small in terms of preventing type 1 diabetes. Hope in this regard appears to stem from rotavirus vaccination and the use of a drug called teplizumab.

Quite the opposite is the situation in type 2 diabetes. Here, weight loss and combating sedentary lifestyle can halve the risk of diabetes in those with prediabetes. However, anti-rotavirus and teplizumab vaccination do not have proven benefits in the prevention of type 2 diabetes.


Currently, there is no question of a cure for type 1 diabetes that has already entered stage 2 of evolution. Recently, there has been some research progress for stage 1 of the disease (teplizumab).

Metabolic surgery applied to a patient with type 2 diabetes and stage 3 obesity can lead to diabetes cure. The complete remission of diabetes can endure for more than ten years, in some situations. This happens only if the weight loss is significant (> 30 Kg) and persistent over time. A similar bodyweight decrease obtained using diet can lead to the same result.

Who is worse, type 1 or type 2 diabetes?

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From the beginning, I would like to point out that both types of diabetes are dangerous. Moreover, the answer to the question of who is more dangerous between type 1 and type 2 diabetes only matters if you ask the question correctly. There is a correct way to ask and an incorrect one. Let’s see together what these are!

Be careful how you put the question because you’ll get the answer to whatever you asked. You will not get the answer to what was on your mind and wanted to find out. The correct way to ask is to indicate that you wish for an evaluation from the perspective of two patients of the same age getting different types of diabetes at the same time.

The wrong way to ask is to demand a comparison between a type 1 diabetes child and a 60-year-old type 2 diabetes adult, both at diabetes onset. In conclusion, what should interest you is to find out the answer to the question: “If I were to get diabetes tomorrow, what would be worse, type 1 or type 2?”.

The short answer

For a patient at diabetes onset, in any age group, type 2 diabetes is a diagnosis associated with a significantly lower life expectancy compared to type 1. Life expectancy means how many years remained for living from that moment. The same is valid from the quality of life perspective.

As a result, we can conclude that, if it does occur, type 2 diabetes is more dangerous than type 1 diabetes.

Arguments related to mortality

The main argument under evaluation refers to life expectancy. Survival is lower in the case of type 2 diabetes diagnosis than for type 1. The reason is that often other metabolic or cardiovascular diseases accompany type 2 diabetes. Studies have shown that a patient with type 2 diabetes lasting for about ten years has a life expectancy similar to a patient who has had a heart attack and has no diabetes.

The main conditions that accompany type 2 diabetes are high blood pressure, dyslipidemia and ischemic heart disease. Each of these conditions can further contribute to the increased risk of death.

High blood pressure and increased fat in the blood

High blood pressure starts before the diagnosis of type 2 diabetes. In type 1, it usually occurs only after diabetes complicated with stage 3 chronic kidney disease.

“Dyslipidemia” means increased fat in the blood. “Atherogenic” refers to the ability of blood fat to stick to vessels and clog them. Atherogenic dyslipidemia is the combination of increased blood triglycerides and low HDL cholesterol. “HDL cholesterol” (“good” cholesterol) is that part of cholesterol that protects us from “bad” cholesterol.

Besides, the LDL cholesterol of patients with type 2 diabetes is composed of numerous, small and very dense particles. “LDL cholesterol” is that part of the cholesterol that is “bad”, that is, it hampers the blood vessels.

Accelerated atherosclerosis

The combination of atherogenic dyslipidemia and small and dense LDL cholesterol characterizes type 2 diabetes. However, it can also occur in chronically uncontrolled type 1 diabetes.

The direct consequence is the emergence of an accelerated ageing process of the blood vessels. In type 2 diabetes, blood vessels become stiffer and clog up faster than expected. This defines accelerated atherosclerosis.

Quality of life arguments

Compared with type 2, type 1 diabetes patients need to pay at least ten times more attention to diabetes care. The time consumed for the various procedures related to type 1 diabetes amounts to about two hours a day, every day. In oral-treated type 2 diabetes, this time is generally less than 30 minutes.

The ten main arguments for the type 1 diabetes patients higher burden are as follows:

  1. Insulin treatment from the onset for all
  2. Multiple doses of insulin per day from the first moment
  3. Multiple blood glucose determinations daily
  4. A temporary complete break from treatment is out of discussion
  5. The diagnosis occurs at an earlier age
  6. The chance for a worry-free childhood suddenly disappears for the affected child
  7. If they revolt and test their limits, they find out what ketoacidosis means
  8. Time spent with diabetes is more extended than without diabetes
  9. More frequent and severe hypoglycemia
  10. They can’t blame anything for the onset of the disease

The quality of life reduction is higher in type 1 diabetes

All these things seem to advocate for a much better quality of life in type 1 diabetes compared to type 2 diabetes. Studies done to elucidate why type 2 diabetes patients have a worse quality of life compared with type 1 have found something interesting.

Who reduces the quality of life the most? It doesn’t seem that the procedures related to diabetes care are the ones that lower the quality of life the most. The highest decrease in the quality of life comes from the onset of diabetes complications. A significantly longer time passes from diagnosis to the first complication in type 1 compared to type 2 diabetes.

Moreover, type 2 diabetes may already have complications at the moment of diagnosis. The explanation is that its actual onset is often at least five years before. Sometimes, a mild form of type 2 diabetes mellitus may persist without symptoms ten or more years before the diagnosis.

The risk of type 1 diabetes

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The risk of type 1 diabetes has a dedicated chapter. In short, it is increasing worldwide. Type 1 diabetes accounts for about 10% of all diabetes cases. Each year, approximately 100,000 children develop type 1 diabetes internationally. Type 1 diabetes most often occurs in a child without other relatives affected by the disease. Thus, only 10% of children with type 1 diabetes have someone in the family with diabetes.

Type 1 diabetes causes

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The causes of type 1 diabetes have a dedicated chapter. They refer to the exact reasons why cells in the immune system begin to attack pancreatic beta cells. Pancreatic beta-cell destruction occurs most often over many years, sometimes even decades. As a result, the causes of type 1 diabetes are complex and often lost in time by the moment of clinical onset.

Type 1 diabetes symptoms

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Type 1 diabetes symptoms have a dedicated chapter. The main symptoms of type 1 diabetes in children are intense thirst and frequent urination, including during the night. Children typically consume more water than an adult. For this reason, an increase in water consumption doesn’t immediately make the parents worry about their child. Weight loss, fatigue, blurred vision and finally, nausea and vomiting are the ones that alert the parents. Unfortunately, all these signs appear only late in the course of the disease onset.

Stages of type 1 diabetes development

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The stages of type 1 diabetes have a dedicated chapter. In short, there are four stages of type 1 diabetes development. Type 1 diabetes is a disease that can run for many years before the blood sugar levels rise. The hyperglycemic onset of type 1 diabetes marks his entry into stage 3. Nowadays, well-trained doctors diagnose type 1 diabetes many years before blood glucose levels start to rise.

Diabetic ketoacidosis

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Diabetic ketoacidosis (DKA) has a dedicated chapter. It is a life-threatening, acute complication of type 1 diabetes. Its main characteristics are hyperglycemia, increased ketone bodies and decreased blood bicarbonate. The leading cause is the lack of sufficient insulin for the body’s temporary need. As a result, severe dehydration, increased heart rate and shortness of breath appear quickly.


  1. American Diabetes Association Guideline 2020
  2. ISPAD Clinical Practice Consensus Guidelines 2018
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