When people think about diabetes, they typically think of type 1 or type 2 diabetes. But, a new form of diabetes has recently gained attention: Type 4 diabetes. Though it isn’t yet a formal diagnosis, experts estimate that around 20% of recently diagnosed diabetes cases in patients older than 65 should be categorized as type 4 diabetes.

This article will provide an overview of type 4 diabetes, including its causes, symptoms, and available treatments.

What Are The Other Types of Diabetes?

Understanding the other types of diabetes can help clarify the unique properties of type 4 diabetes.

Type 1 Diabetes

Type 1 diabetes is an autoimmune disease that most commonly appears in kids, teens, and young adults, though it can occur at any age. It develops when the patient’s pancreas produces insufficient insulin, or none at all, because the immune system mistakenly attacks insulin-producing pancreatic cells. Insulin is a necessary hormone for blood sugar management.

An estimated 5% to 10% of diabetes cases in the U.S. are type 1 diabetes, making it significantly less common than type 2 diabetes.

Type 2 Diabetes

Type 2 diabetes may also be referred to as adult-onset diabetes, though it can develop in childhood. It’s more prevalent among older adults because its risk factors are primarily lifestyle-related, including a lack of physical activity and being overweight or obese. Additionally, type 2 diabetes develops over time, so it often doesn’t begin to cause symptoms until later in life.

Latent Autoimmune Diabetes in Adults

Latent autoimmune diabetes in adults, or LADA, is a type of autoimmune diabetes that progresses slowly over time. Unlike type 1 diabetes, patients frequently don’t require insulin for many months (or even years) after receiving the diagnosis.

LADA is commonly considered a subtype of type 1 diabetes because it occurs when the immune system attacks insulin-producing pancreatic cells. However, some researchers categorize LADA as “type 1.5” diabetes, occurring on a spectrum between type 1 and type 2 diabetes.

Gestational Diabetes

Gestational diabetes is a form of diabetes that can appear during pregnancy. Approximately 2% to 10% of pregnancies in the U.S. involve gestational diabetes.

Pregnancy triggers hormonal fluctuations and various bodily changes, including weight gain. In some women, these shifts lead to insulin resistance, which occurs when the body’s cells don’t respond effectively to insulin.

Gestational diabetes often doesn’t cause any symptoms. This makes it crucial to get tested for gestational diabetes early in pregnancy. Beginning treatment as early as possible helps protect the health of the mother and baby.

Type 3 Diabetes

Like type 4 diabetes, the existence of type 3 diabetes has only recently been indicated by researchers. Type 3 diabetes is a term used in conjunction with the idea that insulin resistance may lead to Alzheimer’s disease.

Type 3 diabetes isn’t an official diagnosis and is still being explored by medical experts.

Type 4 Diabetes: Overview

Type 4 diabetes is a suggested diagnosis for cases of diabetes in older adults who aren’t overweight or obese. Since this form of the condition isn’t associated with weight, it doesn’t fall under the umbrella of type 2 diabetes and may be related to the aging process.

Physicians and patients alike often believe that maintaining a healthy weight protects against diabetes. So, the type 4 classification may help address the underdiagnosis of diabetes in older adults who are at a healthy weight.

Type 4 Diabetes Research

The possibility of type 4 diabetes was first discovered in a study conducted by Ronald Evans and Ye Zheng’s labs at the Salk Institute. This study revealed that some cases of diabetes in old, slender mice didn’t result from the same cellular cause as type 2 diabetes, which is triggered by excess weight.

Instead, the older mice with type 4 diabetes exhibited unusually high amounts of T regulatory cells (a type of immune cell) in fat tissue. In the mice with type 2 diabetes, unusually low amounts of T regulatory cells were found in the fat tissue. These levels were recorded even though the mice with type 2 diabetes had more fat tissue.

Treatment to block the buildup of T regulatory cells in fat tissue helped eliminate type 4 diabetes in mice. The researchers of this study have now partnered with research institutes and hospitals to conduct clinical trials, which will determine if this form of treatment could help humans with type 4 diabetes.

What Causes Type 4 Diabetes?

Given that researchers are still in the early stages of learning about type 4 diabetes, its exact causes aren’t yet known. However, researchers theorize that it’s associated with the aging process. Although not all older adults develop age-related insulin resistance, in some people, aging causes a buildup of T regulatory cells.

What Are The Symptoms of Type 4 Diabetes?

The symptoms of type 4 diabetes are similar to those seen in type 2 diabetes cases. These include:

  • Fatigue
  • Frequent urge to urinate
  • Increased thirst and hunger
  • Unexplained weight loss
  • Impaired wound healing
  • Blurry vision

Several of the symptoms listed above are associated with other conditions, which can make it difficult to decisively diagnose diabetes. However, if you’re experiencing any of the symptoms listed above, schedule an appointment with your physician.

Fatigued female senior

How is Type 4 Diabetes Diagnosed?

As aforementioned, type 4 diabetes isn’t yet an official diagnosis. However, if you’re over the age of 65, at a healthy weight, and experiencing diabetes symptoms, your physician can conduct an evaluation for age-related insulin resistance. You’ll likely need to undergo a physical exam, blood work, and other testing to conclusively determine the cause of your symptoms.

With your test results, your physician can provide the best treatment route to address your symptoms.

How is Type 4 Diabetes Treated?

Considering its recent discovery, a treatment for type 4 diabetes is still in the early stages of research and development. Researchers at the Salk Center aspire to produce an antibody medication that could lower T regulatory cells, thus addressing the root cause of type 4 diabetes.

However, as this medication is developed, physicians generally treat patients with type 4 diabetes as they would treat type 2 diabetes patients. Type 2 diabetes treatment often involves medications and lifestyle adjustments.

Diabetes Medications

Insulin is one of the most common medications for diabetes management. Treating diabetes with an insulin pump or injections helps regulate patients’ blood sugar levels.

Not all type 2 and type 4 diabetes patients will require insulin. But, those that do can choose between many different types of insulin available today, including short-acting, rapid-acting, intermediate-acting, long-acting, and premixed insulin.

Other medications that may be used to treat type 2 or type 4 diabetes include:

  • GLP-1 receptor agonists (i.e. Ozempic® and Mounjaro®), medications that help the body use more insulin, decrease appetite, and slow down stomach emptying
  • Biguanides (i.e. metformin), medications that lower the amount of glucose produced by the liver
  • Alpha-glucosidase inhibitors (i.e. acarbose and miglitol), medications that aid the body’s ability to break down table sugar and starches
  • Bromocriptine, a dopamine-2 agonist that may help avert insulin resistance
  • GLP-
  • DPP-4 inhibitors, medications that can lower blood sugar levels without triggering hypoglycemia
  • Meglitinides, medications that support the body’s ability to release insulin
  • Thiazolidinediones, medications that reduce glucose in the liver
  • SGLT-2 inhibitors, medications that help the body get rid of glucose through urine

Injecting insulin

Diabetes Lifestyle Changes

Type 4 diabetes is characterized by insulin resistance despite a healthy weight. So, several of the lifestyle adjustments that help type 2 diabetes, like weight loss, don’t improve cases of type 4 diabetes.

Can Type 4 Diabetes Be Prevented?

With the current information about type 4 diabetes, aging is thought to be the condition’s leading risk factor. Of course, aging is inevitable. So, without further information, there’s little that patients can currently do to prevent type 4 diabetes.

However, patients can work to maintain healthy blood sugar levels with the following tips:

  • Stay physically active
  • Eat a balanced diet that’s rich in plant-based and fiber-rich foods
  • Be mindful of your carb intake
  • Staying hydrated, as water helps the kidneys remove excess sugar from the body
  • Effectively managing stress
  • Getting at seven to nine hours of high-quality sleep each night