Latent autoimmune diabetes in adults, or LADA, is an atypical type of diabetes. Meaning, it has features of both type 1 diabetes (T1D) and type 2 diabetes (T2D).

At first, LADA looks a lot like T2D, but over time, insulin production diminishes. That’s because LADA is a slow, progressive form of autoimmune diabetes primarily occurring in adults. Like a person with T1D, those with LADA produce autoantibodies against their insulin-producing beta cells, which is why it is often mistaken for and misdiagnosed as T2D.

Research suggests about 10% of adults living with LADA are initially misdiagnosed with T2D, which isn’t an insignificant finding. Given that misdiagnoses can contribute to life-long complications, quality of life, and even mortality — should autoantibody screening for LADA become common practice?

One research review says yes, calling for longer, longitudinal studies to provide more evidence for GAD screening. Or, with low clinical suspicion of LADA, using C-peptide testing as an affordable secondary screening tool.

 

What distinguishes LADA from T2D? 

Having at least one positive autoantibody test can help to identify what type of diabetes someone has. However, testing is not being done regularly, and people’s health can be left hanging in the balance.

Current recommendations are that all individuals newly diagnosed with T2D undergo glutamic acid decarboxylase (GAD) testing for LADA — in addition to other tests —when T2D treatments remain ineffective, and suspicion for LADA is increased.

While there are many autoantibody tests, the one used most frequently to identify LADA is glutamic acid decarboxylase (GAD) testing. In addition, C-peptide testing may be ordered, and often, both tests are used. Despite the availability of testing, they’re often underutilized. Let’s look at what they measure.

 

Glutamic acid decarboxylase (GAD) testing is looking for autoantibodies against GAD, whose presence may be a sign of early autoimmune activity. Meaning, the beginning of an attack on insulin-producing beta-cells.

C-peptide testing measures how much insulin your body is making, which can help to provide a differential diagnosis because:

  • People with autoimmune diabetes typically have low C-peptide levels (low insulin levels)
  • People with T2D typically have high C-peptide levels (high insulin levels)

 

Receiving a diagnosis of one type of diabetes, only to be diagnosed with another years later, can take its emotional and physical toll. Lynda Jimenez, also known as @ladawithlynda, shared her diagnosis story with T1D Exchange.

“As an 18-year-old college freshman, I didn’t know enough about diabetes to ask questions when a doctor at the campus health center told me I had T2D,” said Jimenez. “I accepted it and, along with it, the stigma, shame, and loneliness. I felt odd being a young adult with a type 2 diabetes diagnosis. I didn’t question my diagnosis until years later — nearly eight years, to be exact.”

“After having my son, the methods I was using to manage my pre-pregnancy condition were no longer working. While I had started taking insulin during my pregnancy, I was supposed to go back to the same diet, exercise, and oral medication routine I was on. But that didn’t happen.”

“My insulin needs kept rising, leaving my endocrinologist and I wondering. That’s when she asked me if I was ever tested for ‘what type of diabetes’ I had. I hadn’t even known such a test existed! She tested both my GAD antibodies and C-peptide levels. With my GAD antibodies high and my C-peptide levels low, she re-diagnosed me with Latent Autoimmune Diabetes in Adults (LADA),” explained Jimenez.

 

Managing LADA

In general, people with LADA may not need insulin therapy for a year or so after it develops. Throughout this time, lifestyle changes and T2D medications may help to balance glucose levels. But over time, as basal cell functioning declines, glucose levels won’t be as responsive, and insulin will be necessary.

Moreover, with a delayed LADA diagnosis and prescriptions for T2D medications, such as sulfonylureas (i.e., Metformin), the loss of beta cell functioning can be accelerated. Which is a devastating side effect that highlights the importance of proper diagnosis and treatment.

Regardless of growing attention to LADA, this life-long autoimmune condition continues to be unrecognized, misdiagnosed, and mistreated.

If you’ve been diagnosed with T2D, consider asking your healthcare provider if you’ve been tested for LADA, especially if you went through a successful management phase followed by a decline phase. Discovering LADA can help to change the trajectory of your health with diabetes.

“Since I’ve been re-diagnosed, I have been able to gain better management of my diabetes. I am once again on insulin, this time permanently, and while it was an adjustment, it has helped me have better blood sugars and more freedom around eating,” explained Jimenez. “I also have greater access to therapies like a CGM and insulin pump — items previously denied to me with a T2D diagnosis. And, most of all, I have an answer. An answer to the questions I should have asked years ago.”