Latent autoimmune diabetes in adults (LADA) is a disorder in which,
despite the presence of islet antibodies at diagnosis
of diabetes, the progression of autoimmune β-cell
failure is slow. LADA patients are therefore not insulin requiring, at
least
during the first 6 months after diagnosis of
diabetes. Among patients with phenotypic type 2 diabetes, LADA occurs in
10%
of individuals older than 35 years and in 25% below
that age. Prospective studies of β-cell function show that LADA
patients
with multiple islet antibodies develop β-cell
failure within 5 years, whereas those with only GAD antibodies (GADAs)
or only
islet cell antibodies (ICAs) mostly develop β-cell
failure after 5 years. Even though it may take up to 12 years until
β-cell
failure occurs in some patients, impairments in the
β-cell response to intravenous glucose and glucagon can be detected at
diagnosis of diabetes. Consequently, LADA is not a
latent disease; therefore, autoimmune diabetes in adults with slowly
progressive
β-cell failure might be a more adequate concept. In
agreement with proved impaired β-cell function at diagnosis of
diabetes,
insulin is the treatment of choice.
As part of their study, the researchers also looked for the same auto antibodies in the general population and in people with type 2 diabetes (which is not an autoimmune disease). The proteins were virtually absent in the general population, but they showed up, to the scientists’ surprise, in about 10 percent of people diagnosed with type 2. This suggested that there was a subcategory of people who could now be diagnosed as having LADA instead, even though there was no obvious difference in their symptoms from those of people with type 2.
While not everyone has settled on calling the condition LADA (some prefer “type 1.5”), or even whether it’s distinct from type 1, researchers are working on a set of criteria for its diagnosis: 1) the presence of autoantibodies in the blood, 2) adult age at onset, and 3) no need for insulin treatment in the first six months after diagnosis. This definition would distinguish LADA from type 1—because people diagnosed with type 1 typically need to start insulin immediately—and from type 2, because of the presence of auto antibodies in the blood.
1. You are diagnosed with Type 2 diabetes while at a normal weight.
2. Whatever your weight, either you or a member of your family has some other autoimmune disease such as thyroid disease, rheumatoid arthritis, lupus, or multiple sclerosis.
3. You lower your carbohydrate intake shortly after diagnosis to no more than 15 grams a meal and still have a fasting blood sugar over 110 mg/dl and blood sugars that rise 40 mg/dl or more after each meal.
4. No matter what your weight, you do not see a dramatic drop in your blood sugar when you take metformin, Avandia, Actos, Januvia or Byetta in combination with a lowered carbohydrate intake.
5. Your blood sugar deteriorates significantly over the period of a year despite treatment with oral drugs and carbohydrate restriction.
If you think you have LADA ask your doctor for:
1. A fasting C-peptide test. If the value is low, it is suggestive of LADA.
2. GAD and Islets antibody tests. High levels of these antibodies are diagnostic of LADA especially in combination with lowered C-peptide.
| Diabetes Types Key characteristics of type 1, LADA (latent autoimmune diabetes in adults), and type 2. | |||
| Type 1 | LADA | Type 2 | |
| Typical age of onset | Youth or adult | Adult | Adult |
| Progression to insulin dependence | Rapid (days/weeks) | Latent (months/years) | Slow (years) |
| Presence of autoantibodies* | Yes | Yes | No |
| Insulin dependence | At diagnosis | Within 6 years | Over time, if at all |
| Insulin resistance | No | Some | Yes |
SURPRISE FINDING
Doctors stumbled upon the LADA phenomenon quite by accident back in
the 1970s. They were testing a way of identifying proteins called
auto antibodies in the blood of people with type 1. The presence of
these proteins is evidence of an attack by one’s own immune system. The
new test was successful and confirmed for the first time that type 1 is
an autoimmune disease in which the body’s immune system kills off the
beta cells in the pancreas, the makers of insulin. As part of their study, the researchers also looked for the same auto antibodies in the general population and in people with type 2 diabetes (which is not an autoimmune disease). The proteins were virtually absent in the general population, but they showed up, to the scientists’ surprise, in about 10 percent of people diagnosed with type 2. This suggested that there was a subcategory of people who could now be diagnosed as having LADA instead, even though there was no obvious difference in their symptoms from those of people with type 2.
While not everyone has settled on calling the condition LADA (some prefer “type 1.5”), or even whether it’s distinct from type 1, researchers are working on a set of criteria for its diagnosis: 1) the presence of autoantibodies in the blood, 2) adult age at onset, and 3) no need for insulin treatment in the first six months after diagnosis. This definition would distinguish LADA from type 1—because people diagnosed with type 1 typically need to start insulin immediately—and from type 2, because of the presence of auto antibodies in the blood.
The Warning Signs YOU May Have LADA
1. You are diagnosed with Type 2 diabetes while at a normal weight.
2. Whatever your weight, either you or a member of your family has some other autoimmune disease such as thyroid disease, rheumatoid arthritis, lupus, or multiple sclerosis.
3. You lower your carbohydrate intake shortly after diagnosis to no more than 15 grams a meal and still have a fasting blood sugar over 110 mg/dl and blood sugars that rise 40 mg/dl or more after each meal.
4. No matter what your weight, you do not see a dramatic drop in your blood sugar when you take metformin, Avandia, Actos, Januvia or Byetta in combination with a lowered carbohydrate intake.
5. Your blood sugar deteriorates significantly over the period of a year despite treatment with oral drugs and carbohydrate restriction.
What To Do To Get A LADA
Diagnosis
If you think you have LADA ask your doctor for:
1. A fasting C-peptide test. If the value is low, it is suggestive of LADA.
2. GAD and Islets antibody tests. High levels of these antibodies are diagnostic of LADA especially in combination with lowered C-peptide.
