In the beginning there were two types of diabetes: juvenile and adult. But the names were poorly chosen. First, they can actually refer to different diseases. And second, either one can strike at any age.

That is, type 1 diabetes is an autoimmune condition in which the immune system mistakenly kills off the cells in the pancreas that make insulin, nature’s blood sugar regulator. Type 2 diabetes is a condition of “insulin resistance” in which the body still makes insulin, but is unable to process it properly.

Once upon a time, it was believed that only children get type 1 diabetes, therefore it was called “juvenile diabetes.” But in recent years it has become clear (and increasingly common) that adults of all ages get the autoimmune type of diabetes too.

This has become known as LADA (latent autoimmune diabetes in adults), but the term is a controversial one.

In 1979 the terms “adult diabetes” and “juvenile diabetes” were replaced with our modern type 1 and type 2. Gestational diabetes was thrown in to describe a sometimes temporary diabetes diagnosed during pregnancy, and the experts thought they had all the bases covered.

But then a problem arose. Some people who developed the autoimmune type 1, especially as adults, were… well… different. The disease didn’t follow the normal rules. In particular, adults with this slow-motion type 1 could go for many months, sometimes years, before insulin had to be started. So eventually in the mid-1980s, the research community coined the term latent autoimmune diabetes in adults, aka LADA.

But despite the fact that today many adult onset PWDs (people with diabetes) self-identify as LADA, it is not an officially recognized nor universally accepted label. Leading medical organizations that do not use or recognize the term include the American Diabetes Association, American Association of Clinical Endocrinologists, American College of Endocrinology, World Health Organization, Centers for Disease Control, and National Institutes of Health.

So how is this even a thing? Why is the term still used and how is it defined?

In fact, the only professional diabetes organization that officially recognizes LADA is the Immunology of Diabetes Society, which proposes a definition that boils down to:

  1. Diagnosis of diabetes in a person over 30 years old.
  2. Presence of any islet cell antibody.
  3. No insulin needed for at least 6 months.

But it’s not so simple. For one thing, the hallmark slow onset of LADA is also sometimes seen in people younger than 30. And some patients older than 30 can go longer without insulin than “typical” type 1s, but still end up needing it in less than 6 months.

In short, the lines are fuzzy here. Many experts believe LADA is different disease from type 1, others say it’s just another flavor of type 1, and others still think the LADA label should be thrown out altogether.

Paolo Pozzilli and Umberto Di Mario, writing a commentary in the journal Diabetes Care, said of LADA, “This term has been largely used in the last few years when referring to autoimmune forms of diabetes not requiring insulin initially. Now it is clear that diabetes in these patients is not latent and is not limited to adults.”

Yet other researchers are calling for a refined definition, or a different one, including ADASP, for “autoimmune diabetes in adults with slowly progressive beta-cell failure.” That’s a mouthful.

In addition to this scientific wrangling over LADA, it creates a significant problem for clinicians and, more importantly, for patients. Since LADA doesn’t fit neatly into a shoebox, many patients with LADA (or whatever you call it) are misdiagnosed and wrongly treated.

Because this flavor of autoimmune diabetes generally strikes older people, who are sometimes heavier, develops more slowly than traditional type 1, and often responds initially to oral medications, it is frequently mistaken for type 2 diabetes — leading to inappropriate therapy, especially a delayed start of insulin.

So… wait a sec… just how is LADA diagnosed?

In most cases, when an adult is discovered to have elevated blood sugar, and the person isn’t in a metabolic crisis, it’s assumed they have type 2 diabetes, and treatment proceeds accordingly. It is only when treatment begins to fail, generally in 6 months to several years, that a deeper dive is undertaken and the true nature of the diabetes — an autoimmune assault — is discovered.

For some adults, however, the onset of autoimmune diabetes is more dramatic and obvious. It presents just the way type 1 diabetes does in younger people: with a bought of incessant thirst, frequent urination, rapid weight loss, fatigue, and blurry vision.

And even then, some clinicians will call it LADA, while others simply call it type 1. Like Supreme Court Justice Potter Stewart’s classic definition of pornography, LADA defies definition, but… we know it when we see it.

Technically, a formal diagnosis of LADA would include insulin antibody tests, but in the absence of any diagnostic criteria for LADA, this is rarely done in the trenches.

Meanwhile, like everything about LADA, experts argue about the length of time that it simmers below the surface before presenting, with some doctors arguing that it could be as long as 15 years.

Like type 1, LADA is caused by the immune system destroying the insulin-producing beta cells in the pancreas. Unlike type 1, however, this destruction is a somewhat slow process. For some patients, oral medications or very tiny amounts of insulin may be effective for a while.

In other words, people with LADA tend to experience a prolonged diabetes “honeymoon phase,” in which there is some residual beta cell function, and they can achieve normal or near-normal blood sugar levels by taking only minimal amounts of insulin.

But the end result of LADA and type 1 are the same: a total dependence on external insulin. And like other forms of diabetes, it’s now clear that LADA can happen at any age.

How common is it? One study suggests that LADA is almost as common as type 1, is more common in males than females, and that — like type 2 — family history has a larger part to play than it does with traditional type 1.

Research published in the journal Diabetes Care in 2007 notes, “Interestingly, people with LADA who have higher levels of antibodies are less likely to have a family history of diabetes. Those with lower levels of antibodies are more likely to have a family history of diabetes…

A tentative explanation could be that less autoimmune activity is required to cause LADA in individuals with genetic susceptibility to diabetes (i.e., genetic susceptibility of a kind that is unrelated to autoimmunity).”

What is an autoimmune disease? And why do people get them?

See: Autoimmune Diseases: Types, Symptoms, Causes, and More

What scientists know is that type 1 (autoimmune) diabetes involves an inherited susceptibility to developing the disease, and if a family member has (or had) type 1, you are at a higher risk. If both parents have (or had) type 1, the likelihood of their child developing type 1 is higher than if just one parent has (or had) it.

But they don’t know exactly how it is passed down. A sweeping nationwide study called TrialNet has been researching that since 2000.

Some patients, doctors, and researchers refer to LADA as type 1.5 diabetes, another nonofficial term for “late” autoimmune diabetes in adults. This is further complicated by the fact that a rare genetic form of diabetes called MODY is also sometimes referred to as type 1.5.

The bottom line is that all adults who require insulin to survive will have the same treatment options, and face the same health risks, known as “complications” of diabetes.

The only real difference is the progression of the disease, which has kicked off later for those diagnosed later in life. As diabetes is a progressive disease, all patients generally need to increase their insulin (or other medication) doses over time.

Like all forms of diabetes, a cure for LADA remains elusive, and even the proper course of treatment remains controversial.

The core treatment is of course insulin, but the timing of the start of insulin is problematic. If started too early, the patient will suffer lots of hypoglycemia (severe low blood sugar). If started too late, the risk of complications increases. Unlike other forms of diabetes, there’s no therapeutic guidance or treatment algorithms from professional organizations. Doctors have to wing it.

Meanwhile, researchers are investigating what future therapies might be brought to bear to extend the already lengthy (relatively speaking) insulin-free “honeymoon period” that is the agreed-upon hallmark of so-called LADA.

One company in this area is Diamyd Medical, which is developing a vaccine to prolong that honeymoon period when insulin is not (or barely) needed. This is still in study phase so it will be some time before it could be used in clinical practice.

Any diagnosis of diabetes signals a major change in lifestyle, and this is no different for those with LADA, which generally hits in young-to-middle adulthood, when people are already set in their ways.

One advantage of being diagnosed in adulthood, rather than childhood, is that the negative health complications have less time to develop. But the sudden adjustment in lifestyle required and the psychosocial impact of being diagnosed with the autoimmune form of diabetes later in life is profound.

Some describe it as an “identity crisis” that can bring confusion, sadness, and anger. Others describe mourning a loss a freedom in a way that those diagnosed with type 1 as children never knew.

Open communication with loved ones, and both in person and online support from peers also living with diabetes, are key.

There is a lot of research on LADA, but much of it focuses on how blurred the lines are between type 1 diabetes and LADA. Meanwhile, much of the professional literature focuses on how the label should be defined, and whether or not the label should even exist.

Is further research even necessary?

“(LADA) probably has its own genetics and autoimmunity to it, an overlap with ‘classic’ type 1 and even possibly with type 2… But currently definitions are less important than treatment, which is with insulin, like a ‘classic’ type 1. So clinically we should care less about the name and more about the whole patient,” says Dr. Anne Peters, director of clinical diabetes programs at the University of Southern California.

There is an unfortunate lack of books or toolkits designed specifically for people with LADA. But since it is nearly indistinguishable from type 1 once fully developed, most resources for that disease apply.

In the end, LADA is a different route to the destination — type 1 diabetes — but once you’ve arrived, all the tools and tactics brought to bear on type 1 will work for you.

A few places for LADA-specific info:

This article has been medically reviewed by Marina Basina, MD, on 10/9/2019.