People with type 1 diabetes have a high level of the pancreatic autoantibodies that attack and destroy the beta cells that produce insulin. This causes blood glucose to increase without any control.
People with type 2 diabetes have a combination of increased insulin resistance and decreased insulin secretion. They usually don’t have the autoantibodies that are present with type 1 diabetes.
In people with LADA varying amounts of pancreatic autoantibodies can be found. Depending on the level of these autoantibodies the beta cells are destroyed at a slower rate than those with type 1 diabetes. This means people with LADA do not need insulin at the beginning of treatment but they will do in the future.
Whereas those who have type 1 diabetes need treatment with insulin from the onset.
Since some beta cell function is preserved, symptoms of diabetes develop slowly over weeks or months. If you have LADA you may lack some of the typical features of type 2 diabetes. People with LADA are usually younger (average age of 30) when they’re diagnosed. They’re less likely to be obese and are often physically fit. Their blood sugar remains high despite taking some oral anti-diabetic medications. There may also be no evidence of ketoacidosis on diagnosis, but this may develop later on.
Ketoacidosis occurs where there is insufficient insulin to use the circulating glucose for energy and the body then starts to break down fatty tissue for energy. This ultimately leads to the production of ketones which may cause a serious condition called metabolic ketoacidosis.
What are the symptoms of LADA?
The symptoms are usually similar to the classic symptoms of other forms of diabetes such as excessive thirst, frequent urination, blurred vision, extreme weakness and fatigue, slow healing of the wounds and dry itchy skin.
How is it diagnosed?
Initially, a patient is diagnosed as having diabetes in the usual way, either by fasting blood glucose measurement or by an HbA1c measurement.
If someone isn’t responding to treatment with oral medications, has other autoimmune conditions (such as certain thyroid diseases, rheumatoid arthritis or coeliac disease) or is not overweight then the diagnosis of LADA should be considered. In these cases, a blood test for pancreatic autoantibodies called a ‘GAD (Glutamic acid decarboxylase) antibody test’ may help to distinguish people with LADA from those with type 2 diabetes.
The presence of autoantibodies can identify LADA and can also predict how quickly the person is likely to stop producing their own insulin. It’s important to note that the GAD antibody test is not routinely carried out in the UK at this time.
Why LADA is often misdiagnosed as type 2 diabetes?
LADA is often misdiagnosed as type 2 diabetes because the symptoms are often similar. The initial tests to confirm the diagnosis of diabetes are the same. Unless someone suspects the diagnosis of LADA at this point, then the initial management and treatment is the same.
As previously mentioned, failure to respond to treatment with oral medications, the presence of other autoimmune conditions and not being overweight often then prompts someone to consider a diagnosis of LADA.
What’s the treatment?
The aim of treatment of LADA is focused on preserving the beta cells from being destroyed and maintaining blood glucose within normal limits to avoid complications.
As in type 1 and type 2 diabetes, LADA is treated with the correct diet and exercise regime. Unlike type 1 diabetes, insulin injections aren’t prescribed at diagnosis because people with LADA have some of their own natural insulin.
Medications such as ‘metformin’ or ‘pioglitazone’ may be prescribed. Insulin injections are introduced at a later stage depending on the degree of blood glucose control, level of autoantibodies present and the risk of complications.
What are the complications of LADA?
The complications of LADA are similar to that of type 2 diabetes:
- macrovascular complications such as cardiovascular disease and
- microvascular complications such as retinopathy.
What about diet?
As with other forms of diabetes, a healthy diet should be followed. Many people with LADA aren’t obese and are physically active but they should aim to keep their blood sugars stable and avoid sudden surges of high blood sugars. Your doctor may refer you to a dietician to help maintain stable blood sugars especially if you’re on insulin.