Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by a less intensive autoimmune process compared to classical type 1 diabetes mellitus due to a lower evolution of B-cells failure. It shares similar features with both type 1 and type 2 diabetes mellitus with initial insulin dependence which later advances to a degree similar to type 1 diabetes (1). This can lead to a misdiagnosis of type 2 diabetes. A typical characteristic of LADA is the presence of specific autoantibodies for the islet cells. LADA is more prevalent in adults(30-50years) than in children.
LADA versus other types of diabetes.
- It is a form of type one diabetes that shares some similar characteristics as type 2 diabetes hence is sometimes called type 1.5 diabetes (3).
- LADA is a form of type 1 diabetes because it is an autoimmune disease in which autoimmune cells destroy islet cells
- LADA can be mistaken for type 2 diabetes because it takes a longer period to develop than type one diabetes in children. LADA can develop over a period of years
- Due to the slower onset of symptoms in LADA patients, it may lead to the misdiagnosis of LADA as type 2 diabetes
Signs and symptoms of LADA
The initial symptoms of LADA include:
- Persistent tiredness
- Excessive hunger immediately after meals
As the disease progresses, insulin secretion is depleted and leads to symptoms such as:
- Excessive thirst (polydipsia)
- Excessive urination(polyuria)
- Excessive hunger
- Excessive weight loss
- Blurred vision
- Slow healing of cuts
Noticing the symptoms at an early stage reduces the risk of developing complications of diabetes such as heart failure, nephropathy, kidney disease, and glaucoma.
Diagnosis of LADA
LADA is diagnosed by usual diagnostic methods for diabetes. After the diagnosis, your doctor might want to determine the specific type of diabetes. LADA is specifically diagnosed by examining the presence of autoantibodies against islet cells in diabetic patients who do not require insulin. The autoantibodies can be measured using the GAD antibody test.
GAD antibody test can diagnose LADA and also predict the extent to which the disease is progressing towards insulin dependency.
The C-peptide test can also be used to diagnose LADA. The test is however less sensitive because it cannot draw conclusive results in patients at the earlier stages of LADA.
LADA can be misdiagnosed.
Due to the slow onset of the condition, LADA can be misdiagnosed as type 2 diabetes (2). If wrongly diagnosed, it could lead to inappropriate treatment and diabetes control methods. This situation makes the patient more prone to diabetes complications and can also deplete the body’s ability to secret insulin.
Below are some clues that can help in the differentiation of LADA from diabetes type 2:
- Persistent glucose spite despite administration of diabetes drugs
- Presence of other autoimmune diseases like anemia
- Absence of high blood pressure, obesity, and high cholesterol(metabolic syndrome features)
Treatment of LADA.
Due to the slow development of LADA, diagnosed patients may depend on their insulin for a couple of months or years to regulate blood sugar levels. They will however require insulin in the long run due to the progression of the disease (1)
It is advised for LADA patients to check their blood sugar levels regularly (3-4) times a day just like type 1 diabetes patients, especially before and after meals.
Complications of LADA.
The most prominent short term complication of LADA is diabetic ketoacidosis 3). This happens mostly when auto-destruction of the pancreas has killed its ability to produce insulin. Thus LADA patients should pay attention to the signs of ketoacidosis and also know how to test for ketones.
The long term complications of LADA are similar to those of type 1 diabetes. These complications include
The possible long term complications of diabetes include:
- Heart and blood vessel disease
- Nerve damage (neuropathy)
- Kidney damage (nephropathy)
- Eye damage
- Foot damage
- Skin and mouth conditions
- Pregnancy complications
Management of LADA.
When treating LADA, the focus should be drawn towards lowering blood glucose to target levels, and also preventing the development of both short and long term complications. Emphasis should also be laid on the preservation of beta cells for as long as possible. Thus recommended treatments for LADA include insulin, metformin, and thiazolidinediones . Any other drug which can help preserve beta cells is recommended too.
LADA consists of a broad spectrum of clinical and metabolic features, ranging from insulin resistance to insulin deficiency. Affected patients show midway features between type one and type 2 diabetes mellitus. Consequently, LADA remains unnoticed with a high rate of misdiagnosis. Once diagnosed with LADA, the autoantibodies of the patient should be monitored closely. The treatment of LADA is mostly with the use of insulin and insulin sensitizers.