Some adults who have type 1 diabetes (T1D) get diagnosed after the age of 30 and present with characteristics that are usually specific to type 2 diabetes (T2D), such as gradual onset of hyperglycemia and overweight. This form of diabetes is called LADA (latent autoimmune diabetes in adults) or slow-onset diabetes.
Approximately 8% of adults who have signed up for the BETTER registry had a LADA diagnosis.
Despite this large percentage, there are very few studies or guidelines for the care of people with LADA. That’s why an expert panel developed a care consensus for these patients.
Getting the right diagnosis
People with LADA are often misdiagnosed with T2D right from the start.
Since their pancreas still produces some insulin, their blood sugar levels are only moderately high, and they present with clinical signs that are similar to those of T2D. But they also have antibodies that are destroying their pancreas’s beta cells (the insulin-producing cells), which is a sign of T1D. Most of the time, these patients start taking T2D medication that doesn’t treat their high blood sugar.
This misdiagnosis affects the patient’s daily life and can be quite frustrating. Some patients reported that the lack of glycemic control in spite of the medication and lifestyle changes (diet, physical activity, etc.) brought about feelings of guilt and anxiety.
The expert panel recommends that every person who receives a T2D diagnosis get screened for anti-GAD antibodies—which indicate an autoimmune response directed against the beta cells—in order to rule out a LADA diagnosis. However, this protocol would be expensive.
If this protocol is not possible for financial reasons, the experts suggest that screening be limited to patients who present with the following characteristics:
- family history of T1D or autoimmune disease
- normal or slightly overweight body mass index (BMI) (below 27)
- diagnosis at a young age (under 60)
- poor metabolic control
This would help to start an adequate treatment as early as possible.
Choosing the right treatment
When treating LADA, one of the main goals is to preserve the natural secretion of insulin for as long as possible. Since every patient’s beta cells are destroyed at a different rate, the treatment must be customized. LADA patients will eventually need to take four insulin injections per day (or use an insulin pump). But first, treatments that are usually exclusive to T2D are considered because it may be a good option for LADA patients in some cases.
The expert panel’s recommendations include three sets of treatment to administer based on blood C-peptide levels, which indicate how much insulin is produced by the pancreas (the pancreas releases a C-peptide molecule for every insulin molecule it secretes). The treatment can therefore be adapted according to the ability of the pancreas to produce insulin. Here are the consensus recommendations:
- High C-peptide levels (over 0.7 nmol/L): Treat according to recommendations for T2D patients, but closely monitor C-peptide levels, especially when blood sugar levels are difficult to keep in range.
- Moderate C-peptide levels (between 0.3 and 0.7 nmol/L): This is what the experts call the “grey area.” Treatment is defined according to risks of heart and kidney disease and glycated hemoglobin (HbA1c), and is reviewed every six months based on C-peptide levels.
- Low C-peptide levels (under 0.3 nmol/L): Multiple daily insulin injections (i.e., the typical T1D treatment) are recommended.
The consensus includes general and specific recommendations, so that healthcare teams can better support patients with LADA.
Between 2% and 12% of adults with diabetes are estimated to have LADA type 1 diabetes.
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- Buzzetti, Raffaella, et al. (2020). “Management of Latent Autoimmune Diabetes in Adults: A Consensus Statement From an International Expert Panel.” Diabetes, 69(10), 2037–2047. doi:10.2337/dbi20-0017