Latent Autoimmune Diabetes of Adulthood (LADA) is adult onset type 1 diabetes that progresses more slowly than type 1 diabetes diagnosed in younger years.

People with LADA are usually able to produce a significant amount of insulin for a number of years after diagnosis and so insulin therapy may be withheld until it is strictly necessary.

However, research indicates that earlier insulin treatment can help to prolong the body’s ability to keep producing insulin.

LADA is defined by the International Diabetes Federation (IDF) as autoimmune diabetes, characterised by the presence of glutamic acid decarboxylase (GAD) antibodies in the blood, diagnosed in adults between 30 and 50 years old.

It is otherwise referred to as type 1.5 diabetes, or late-onset type 1 diabetes.

LADA symptoms

The symptoms of diabetes mellitus are often found in patients with LADA, but a delay in these symptoms developing can be expected if allowed to progress.

It could between several months and a few years for more noticeable symptoms to appear, but early signs of LADA can be spotted following meals when blood sugar levels are higher, such as:

  • Tiredness
  • Hunger
  • Irritability
  • Brain fog – difficulty thinking clearly

With high blood sugars a common early symptom of LADA, fatigue may be likely as the body struggles to move glucose from the blood into cells.

Some may also experience vomiting and nausea due to a collection of built-up ketones in the blood, especially if LADA is misdiagnosed as type 2 diabetes. Infections and wounds will also generally take much longer to heal.

LADA diagnosis

The first step in diagnosing LADA is to initially test for the presence of hyperglycemia (high blood glucose levels) through one of the following methods:

  • Oral glucose tolerance test
  • A1c test
  • Fasting plasma glucose test

Find out which levels indicate a diagnosis of diabetes.

If the presence of diabetes is confirmed, and LADA is suspected, the next test required is a GAD antibodies test. If the test identifies higher than normal levels of glutamic acid decarboxylase autoantibodies, a diagnosis of LADA will follow.

Another test which can be used is a C-peptide test which measures the amount of insulin in the blood. Typically people with LADA will have lower blood insulin levels than normal.

The GAD antibodies test can also predict the progression rate in which people will become insulin dependent.

Causes of LADA

The causes of LADA are the same for type 1 diabetes, in which the immune system starts to destroy its own insulin-producing beta cells.

The body cannot control its own blood glucose levels once enough insulin-producing cells have been killed off, and diabetes symptoms will start to appear.

Risk factors for LADA include the following:

  • History of type 1 diabetes or autoimmune diseases in the family
  • Having another autoimmune disease

LADA treatment

Controlling hyperglycemia and preventing the onset of any complications is the primary focus of LADA treatment.

People diagnosed with LADA typically do not require insulin treatment within the first six months of diagnosis and can go up to six years before requiring insulin therapy.

Studies have since shown bias towards immediate insulin treatment, however. Many diabetologists prefer to treat LADA patients with insulin upon diagnosis as the immune system starts to destroy beta cells, leaving no reason, in most cases, to postpone insulin therapy. As with type 1 diabetes,

LADA treatment is best accompanied by carbohydrate counting and exercise. Regular blood glucose testing will be required as soon as insulin therapy is initiated.

Once blood sugar levels have come under control, people with LADA often have a lower risk of heart problems.

Short term complications of LADA

As with type 1 diabetes, ketoacidosis is a threat in people with LADA but one that can be prevented with insulin therapy.

Taking insulin means being exposed to the risk of hypoglycemia and so insulin doses must be managed well to minimise the risk of hypos occurring.

Long term complications of LADA

The long term complications for LADA are the same as those for type 1 diabetes and therefore notably include heart disease, stroke, retinopathy, nephropathy and neuropathy.

Because LADA develops slowly, long term complications could start to develop before the condition has been diagnosed.

On the plus side, because the loss of insulin producing beta cells is slower than in juvenile type 1 diabetes, if LADA is diagnosed early and well controlled, it may be easier for people with LADA to avoid complications in their lifetime than for people with type 1 diabetes diagnosed at a younger age.

Misdiagnosis of LADA

LADA is typically diagnosed in adulthood, but is often misdiagnosed as type 2 people in people who are not overweight and have low or no resistance to insulin. LADA can also be diagnosed by people who are overweight.

Misdiagnosis of LADA can result in patients being given incorrect treatment, which can lead to complications later in life.

The slow progression of LADA is another similarity to type 2 diabetes that can result in people being wrongly diagnosed.

As noted above, under diagnosis, specific tests can be run to determine whether LADA is present. These tests are not routinely given, but if you believe you may have been misdiagnosed then you should seek to have these tests performed to clarify your diagnosis.