What Is Latent Autoimmune Diabetes in Adults (LADA)?

Latent autoimmune diabetes in adults (LADA) is an irreversible autoimmune disease that affects insulin function. Although similar to type 1 diabetes, which typically is diagnosed during childhood, LADA develops in adulthood, usually after age 30. For this reason, and because the symptoms are similar, LADA is sometimes first misdiagnosed as type 2 diabetes. In fact, LADA may account for up to 10% of diabetes cases of all types.

Although early on LADA may be manageable with lifestyle changes such as diet and exercise, the condition eventually requires insulin therapy, diabetes medication, or both.

Symptoms of LADA

When it first appears, latent autoimmune diabetes in adults is often misdiagnosed as type 2 diabetes. This is because the symptoms align closely with those of type 2 diabetes and tend to come on slowly over the course of several months.

They include:

• Increased thirst (even with adequate fluids)
• Xerostomia (dry mouth)
• Frequent urination
• Extreme fatigue
• Extreme hunger
• Blurry vision
• Nerve tingling

Whereas type 1 diabetes develops rapidly, the progression of LADA is much slower and may appear to be a slowly progressing form of type 1. (When type 1 diabetes affects a child, it tends to come on suddenly and dramatically.)

One thing to note about LADA is that, unlike type 2 diabetes, it is not associated with excess body weight or obesity. Most people with LADA are unlikely to be overweight and have a body mass index (BMI) below 25 and a low waist-to-hip ratio.

Complications

Without proper diagnosis and prompt treatment, LADA can result in a complication called diabetic ketoacidosis. This is a dangerous condition in which the body starts to break down fat for fuel because no glucose can get into cells.

This occurs when the function of beta cells in the pancreas, which are responsible for the production of insulin, begins to decline. Ketoacidosis can require immediate insulin injection.

Other complications of LADA are the same as those of all types of diabetes, including:

• Diabetic retinopathy
• Diabetic neuropathy
• Diabetic nephropathy
• Cardiovascular complications, such as stroke and acute coronary events

Causes

Like type 1 diabetes, LADA is an autoimmune disease in which the body views beta cells as foreign and attacks them, resulting in a shutdown of insulin production. That said, people with LADA also may develop insulin resistance—the cause of type 2 diabetes.

What may cause someone to develop autoimmune diabetes later in life is not fully understood, but researchers have been able to pinpoint certain risk factors for LADA:

• A family history of autoimmune conditions
• A genetic predisposition to type 1 or type 2 diabetes

Thyroid disease is a common comorbidity with LADA, meaning that the two conditions often coexist. It is not known if one causes the other, however.

Diagnosis

Diagnosing LADA can be tricky. Not all practitioners recognize it as a distinct type of diabetes and may mistake it for type 2 diabetes—at least initially.

Once the disease is suspected, bloodwork may be done to test for the following factors associated with LADA:

• Fasting plasma glucose test: A blood test to measure levels of glucose in the blood after a period of not eating
• Oral glucose tolerance test: A blood test to measure glucose levels after an eight-hour fast followed by consumption of a special sugary beverage
• Random glucose tolerance test: A blood test that looks at glucose levels without fasting
• Hemoglobin A1C test: A blood test that looks at the percentage of glucose attached to hemoglobin (a primary component of red blood cells), which indicates blood glucose control over the past two to three months. A review study found that some patients with LADA had worse blood sugar control and higher A1C levels than patients with type 2 diabetes.
• C-peptide test: A measurement of C-peptides, substances made along with insulin in the pancreas that can show how much insulin your body makes. Low-to-normal C-peptides are associated with LADA.
• Antibody testing: Tests to determine the presence of antibodies, such as autoantibodies to glutamic acid decarboxylase 65 (GAD), islet cell autoantibodies (ICA), tyrosine phosphatase-related islet antigen 2 (IA-2), and insulin autoantibodies (IAA). The presence of at least one of these may signify an underlying autoimmune process taking place. Antibody testing may be a key way to identify LADA and distinguish it from type 2 diabetes.

Treatment

Like type 1 diabetes, LADA is an irreversible condition that requires treatment for life.

Some people with the disease may be able to control their blood sugar early on by making lifestyle changes similar to those necessary for managing type 2 diabetes. These include following a carbohydrate-conscious diet and increasing physical activity.

Treatment may also include oral diabetes medications to help control blood sugar and support insulin output.

However, oral medications and lifestyle changes likely won't be enough to preserve insulin function and control blood sugar levels in the long term. After that point, insulin support will be needed—typically within five years of diagnosis.

Specific oral medications that may be helpful in treating LADA include:

• Dipeptidyl peptidase-4 inhibitors, such as Januvia (sitagliptin)
• Glucagon-like peptide 1 receptor agonists: Ozempic (semaglutide), Trulicity (dulaglutide), Byetta (exenatide), and others)
• Thiazolidinediones

Metformin, a biguanide, which is typically used as a first-line treatment in type 2 diabetes, should be used with caution in LADA. There is a potential risk for a condition called lactic acidosis, a dangerous buildup of lactic acid in the body that may be fatal.

Sulfonylureas, another class of anti-diabetes drugs, should be avoided. They may exhaust beta cells (the cells in the pancreas responsible for producing insulin) and further deplete insulin levels.

A Word From Verywell

A diagnosis of LADA is often surprising given that autoimmune-type diabetes typically is associated with children. If you find yourself worried about or struggling with living with LADA, ask your endocrinologist or a certified diabetes educator about how you might get additional support—for example, through a local or online support group. With time, you'll get to know your disease and how to care for yourself.