Type 1 vs. Type 2 Diabetes

Type 1 and Type 2 diabetes are two very different conditions that have different causes and require different treatment. Type 1 diabetes is a life-long condition that has no clear cause and no cure. People with Type 1 diabetes cannot produce insulin on their own and require insulin injections for the rest of their lives.

Type 2 diabetes is a progressive condition that can develop due to poor diet and exercise as well as genetics. People with this form of diabetes produce insulin, but cells throughout the body cannot import glucose inside the cell due to an insensitive insulin receptor. While they may be able to manage their blood glucose levels with diet, exercise, and medication, the longer an individual has Type 2 diabetes, the more likely they are to need insulin.

Type 2 diabetics typically do not get diabetic ketoacidosis (DKA) because there is almost always just enough insulin to prevent overt ketosis. However, they typically undergo a pathophysiological state called hyperosmolar hyperglycemic state (HHS). This condition is characterized by blood pH higher than 7.3, and glucose levels are at least 600 mg/dL but often much higher, even over 1000 mg/dL. HHS is more difficult to treat and has a higher mortality rate than DKA.

The decision to initiate insulin in a Type 2 diabetic is dependent on whether the maximum tolerated dosage of typical Type 2 diabetes medicines (such as metformin and semaglutide) is sufficient in controlling mean glucose levels, typically a goal of HbA1C 7% or less. An ideal patient that would benefit from insulin injections in the context of Type 2 diabetes would be a thin patient who has an HbA1C of 8.5% despite taking Type 2 diabetic medications with appropriate lifestyle intervention of diet and exercise.

Type 2 diabetes is typically a disease where there is insulin resistance and there is a lot of insulin production but no response to insulin. However, in later stages of the disease, insulin production is small due to beta cell exhaustion and apoptosis, and therefore the patient becomes insulin dependent to control their blood sugar. Additionally, there are some less common genetic causes of Type 2 diabetes that occur in healthy, thin individuals where they also have little insulin production and are insulin dependent.

How Long Can a Type 2 Diabetic Go Without Insulin?

This is a complicated query, as many Type 2 diabetics do not require insulin. Going without insulin can lead a diabetic to develop HHS which is potentially fatal. Type 2 diabetics are very likely to be able to survive without insulin, especially if they are eating a healthy diabetic diet.

However, if a Type 2 diabetic has started using insulin as part of their diabetes treatment, going without it may be dangerous. Type 2 diabetics may develop hyperglycemia (too much glucose, not enough insulin) if they do not properly manage their blood glucose levels. It can take days or weeks for hyperglycemia to develop. If untreated, hyperglycemia can damage the kidneys, heart, eyes, and nerves. HHS may be prevented by checking sugars periodically.

Symptoms of hyperglycemia include:

  • Blurred vision
  • Frequent urination
  • Extreme thirst
  • Weakness
  • Headache

How Long Can a Type 1 Diabetic Live Without Insulin?

Skipping insulin as a Type 1 diabetic is much more dangerous. If a person has been recently diagnosed, they may still have some insulin in their body that will allow them to go a few days or even a week before succumbing to DKA. However, some Type 1 diabetics, particularly children or teenagers, are so dependent on insulin injections that they may show signs of DKA in less than a day.

How long a person is able to survive without insulin also depends on what kind of insulin they are taking and its duration of effect. At the most, a Type 1 diabetic is likely to start seeing signs of DKA within 24 to 48 hours.

Signs of DKA include:

  • Nausea and vomiting
  • Abdominal pain
  • Shortness of breath
  • Fruity-smelling breath
  • Confusion

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.