Most of us are aware that there are several types of diabetes. Type 1 and type 2 diabetes immediately come to mind. There are significantly fewer who have heard about type 1.5 diabetes.

This is surprising as according to some sources, around 15-20% of people diagnosed with type 2 diabetes may in fact have type 1.5 diabetes.

Type 1 diabetes, is usually diagnosed in children, teens, and young adults, but can in fact appear at any age. Type 1 is a chronic condition in which the pancreas produces little or no insulin, the hormone needed to allow blood glucose to enter our cells to produce energy.

In Type 2 diabetes, which is the most common type of diabetes, the body either resists the effects of insulin or does not produce enough insulin to maintain normal glucose levels.

Some researchers maintain that type 1.5 diabetes is a sub-type of type 1 diabetes, while others believe it falls between type 1 and type 2 diabetes.

Read on to learn more about what type 1.5 diabetes is, how it is diagnosed and whether it’s hereditary.  

What’s type 1.5 diabetes?

Type 1.5 diabetes is an unofficial term that is sometimes used to refer to a form of type 1 diabetes known as Latent Autoimmune Diabetes in Adults (LADA). LADA causes the beta cells in the pancreas to stop functioning more quickly than if you have type 2 diabetes.

Type 1.5 diabetes shares some characteristic features of both the type 1 and the type 2 diabetes. It’s a slow-progressing form of autoimmune diabetes, like type 2 diabetes. Like the autoimmune disease type 1 diabetes, it occurs as the pancreas stops insulin production. But unlike type 1 diabetes, people with type 1.5 often do not need insulin for several months up to years after they are diagnosed. Also, unlike type 2 diabetes, it’s a comparatively rare autoimmune disorder that cannot be reversed even after making healthy lifestyle changes.

The symptoms of type 1.5 diabetes are similar to those of type 1 and type 2 diabetes. The symptoms may be vague initially. The common signs of type 1.5 diabetes include increased thirst and urination, unexplained weight loss, and blurring of vision.

If ignored or left untreated, LADA may lead to serious life-threatening complications like diabetic ketoacidosis that occurs when the body is unable to utilize sugars as a source of fuel due to the lack of insulin and hence, starts to burn fats. This results in the production of excessive ketones that could be toxic to your body.

Type 1.5 diabetes diagnosis

It’s estimated that nearly 10% of diabetic patients have type 1.5 diabetes. People with type 1.5 diabetes are usually diagnosed after they reach 30 years of age. 

Patients with type 1.5 diabetes are at a risk of being misdiagnosed as having type 2 diabetes due to the common risk factors they share. People with type 1.5 diabetes are often older when they develop symptoms than the average for someone with type 1 diabetes. Their pancreases may also still produce some insulin for a while, which may further blur the lines.

Initially, type 1.5 diabetes can often be managed by controlling blood sugar levels with a healthy diet, regular exercise and, possibly, oral medications. When misdiagnosed with type 2 diabetes, they’re often treated with anti-diabetic drugs recommended for the management of type 2 diabetes.

However, these drugs can help to control the symptoms of type 1.5 diabetes only until the pancreas gradually loses its ability to produce insulin. It’s at this point that most patients discover that they have type 1.5 diabetes.

The progression toward the need to use insulin is typically much faster with type 1.5 diabetes than with type 2. Also, the response to medications like oral hypoglycemic drugs for lowering blood sugar levels is also poor with LADA.

Hence, it is important to perform certain specific tests to differentiate between type 2 and type 1.5 diabetes. Patients who have type 1.5 diabetes usually meet the following criteria that are contrary to the diagnosis of type 2 diabetes:

• They are not obese.
• They are above the age of 30 years at the time of diagnosis.
• They have difficulties in managing their blood sugar levels with oral antidiabetic drugs or dietary and lifestyle changes.

Blood tests for the detection of specific antibodies that are released as a response to the autoimmune reaction can also help in differentiating these forms of diabetes.

What Are the Main Causes of Type 1.5 Diabetes?        

Type 1.5 diabetes is usually triggered due to the damage to the pancreas from antibodies formed against the insulin-producing cells called the islets of Langerhans. Genetic factors are often implicated as the possible causes responsible for the generation of these antibodies.

Damage to the pancreas caused due to type 1.5 diabetes results in the destruction of the pancreatic beta cells, just like it occurs during the development of type 1 diabetes. Hence, in case a patient with type 1.5 diabetes also happens to be overweight, insulin resistance may also be one of the precursors.

Patients who have a family history of autoimmune disorders are more likely to develop type 1.5 diabetes due to the inherent tendency of the immune system to develop auto-antibodies against the healthy tissues such as the pancreas.

Is Type 1.5 Diabetes Hereditary?

Diabetes is one of the most common lifestyle disorders known to affect millions of people across the world. The risk of diabetes is linked to several factors such as sedentary lifestyle, obesity, and unhealthy dietary habits. Genetics is also found to play a key role in determining the risk of developing this condition.

Family History

Having one or both the parents diagnosed with diabetes could increase your chances of developing it at a much younger age. This marks the need to explore the genetic component of diabetes and understand whether type 1.5 diabetes can be hereditary.

There is scientific evidence linking genetics to the risk of developing type 1.5 diabetes in patients having a family history of the disease. Researchers who calculated the genetic risk scores for measuring whether patients with LADA had genetic profiles that were more similar to those of patients with type 1 or type 2 diabetes, have found interesting results.

The studies revealed that several genetic regions associated with the risk of type 1 diabetes share the genetic region with the risk of LADA. However, relatively fewer gene regions associated with type 2 diabetes may add to the risk of developing LADA. The genetic link of type 1.5 diabetes is also more strongly correlated with the genetic risk factors associated with type 1 diabetes than with type 2 diabetes.

These studies suggest that the chances of developing type 1.5 diabetes are higher in patients who have a family history of this condition.

Moreover, people, whose parents developed any form of diabetes at a younger age, are more likely to develop type 1.5 diabetes than those whose parents developed it at a comparatively older age. 

Furthermore, the chances of developing LADA due to the genetic alleles associated with type 1 diabetes are lower than that of childhood-onset type 1 diabetes, possibly due to the fact that LADA usually appears later during adulthood.

A gene variant that is believed to be one of the strongest genetic risk factors for type 2 diabetes, has no or minimal role in LADA.  This suggests that type 1.5 diabetes is genetically closer to type 1 diabetes than to type 2 diabetes suggesting that some patients diagnosed with type 2 diabetes might actually have a late-onset insulin-dependent type 1 diabetes.

It is important to integrate the genetic findings and the clinical characteristics of these forms of diabetes to be able to classify them more accurately to ensure more effective treatments can be provided to patients.

Autoimmune Conditions

LADA is marked by the presence of auto-antibodies circulating in the blood. This could be an indicator suggesting that an overactive immune system could be responsible for the damage caused to the insulin-producing beta cells in the pancreas.

However, LADA also shares some clinical signs with type 2 diabetes that tends to appear in adulthood. Like in type 2 diabetes, patients with LADA do not always require insulin treatments immediately following the initial diagnosis. This suggests that LADA is more likely to be an autoimmune disorder that develops due to the faulty response of the immune cells against the body’s healthy tissues.

Genetic Research About Type 1.5 Diabetes   

Researchers investigating a specific form of adult-onset diabetes, which shares features with the two better-known and well-researched types of diabetes have discovered that genetic influences could offer clues to the more accurate diagnosis and better treatment outcomes of these conditions.

Researchers have discovered several genetic regions that can increase the risk of type 1.5 diabetes. There are different sets of variants associated with type 1, type 1.5, and type 2 diabetes. This indicates that the risk of type 1.5 diabetes is genetically linked. The development of this condition could be independent of the development of other forms of diabetes. 

What Physical Conditions Can Lead to Type 1.5 Diabetes?         

Obesity

Being overweight or obese can substantially increase the risk of type 1.5 diabetes. Diabetic patients are advised to maintain a healthy weight by adopting a healthy lifestyle and dietary habits with regular exercise and nutritious foods.

Insulin Resistance

Insulin resistance can develop due to autoimmune conditions that make the cells respond to the insulin secreted by the pancreas less efficiently. This can reduce the effectiveness of insulin thus triggering an increase in the blood sugar levels in patients with type 1.5 diabetes.

What Treatments Are Available for Type 1.5 Diabetes? 

Type 1.5 diabetes develops due to the inability of the pancreas to produce enough insulin. However, since its onset tends to be gradual, oral anti-diabetic drugs that are used to manage type 2 diabetes may be helpful, at least initially.

Patients who have type 1.5 diabetes might test positive for one or more antibodies linked to type 1 diabetes. Hence, as the body slows down the production of insulin, patients with LADA may also need insulin as a part of their treatment protocol. Patients with LADA usually require insulin therapy within 5 years of the diagnosis.

The dosage of insulin may vary among different patients. Also, the insulin requirements may change over a period of time Hence, monitoring your blood glucose levels on a regular basis is essential.

Some studies have revealed that the timely diagnosis and treatment of type 1.5 diabetes with oral anti-diabetic drugs and/or insulin might help to improve the outcomes. This is why; getting a correct diagnosis of this condition is highly critical for improving the prognosis and preventing complications.

In terms of complications and the possible prognosis, it has been found that thyroid diseases tend to be more prevalent in patients with LADA than in those with type 2 diabetes. Patients are also more likely to suffer from non-healing wounds and repeated infections.

How Can You Prevent Getting Type 1.5 Diabetes?

Just like type 1 diabetes, there is no effective way to prevent this form of diabetes, possibly due to the involvement of the genetic factors in the development and progression of both these conditions. However, early diagnosis and proper management could help you avoid the complications linked to type 1.5 diabetes.

Other types of diabetes

There are still other types of diabetes. Some researchers have begun to talk about Type 3 diabetes, which is associated with Alzheimer’s disease. Researchers have known for several years that being overweight and having Type 2 diabetes can increase the risk of developing Alzheimer’s disease. We have gone into detail on the risk factors for developing Type 2 diabetes here.

Then there is Gestational diabetes (GDM), which is a type of diabetes that consists of high blood glucose during pregnancy. It is associated with complications for both mother and child. GDM usually disappears after pregnancy but women affected are at increased risk of developing Type 2 diabetes later in life.

Researchers claim that when neurons in the brain become unable to respond to insulin, which is essential for basic tasks, including memory and learning, Type 3 diabetes occurs. Some have even mentioned Type 4 diabetes to describe age-related insulin resistance that occurs in lean, elderly people.

But that is not all. A group of Nordic researchers has recently proposed that there are actually five types of diabetes. This could have significant implications as it could mean that some people are taking diabetes medications they don’t need, while others aren’t being treated adequately at the time of their diagnosis.

Conclusions

It is clear from new medical findings that the diagnosis of diabetes is not as simple as just types 1 and 2 diabetes. You can read more on the difference between type 1 and type 2 diabetes here.

Improved understanding of the different types could help healthcare professionals better predict which individuals are most likely to develop complications and allow a more personalized approach to their treatment.

As for the patients, proper control of your blood sugar levels through regular monitoring, eating a nutritious diet, and adopting healthy lifestyle habits can neutralize some of the influence of genetic factors on your risk of developing LADA. It may also protect you against the risk of complications and enable you to enjoy a healthy and active life.