Myth: Any adult diagnosed with autoimmune diabetes has LADA.
Fact: Some adults will have rapid onset type 1 diabetes and require insulin immediately. LADA is slowly progressive type 1 diabetes. The Latent Autoimmune Diabetes in Adults (LADA) definition, from the International Diabetes Federation (IDF):
• Age of onset >30 years
• Presence of pancreatic islet cell autoantibodies (GAD-65, IA-2, IAA, ZnT8)
• Insulin independent at diagnosis: Unlike classic Type 1 diabetes, the progression of beta-cell damage is slow enough that patients do not require insulin injections for at least the first 6 months following diagnosis.
If a person has been diagnosed with diabetes and is positive for any one autoantibody, the person has Type 1 diabetes. From the ADA Standards of Care in Diabetes (2023): Type 1 diabetes is due to autoimmune β-cell destruction, usually leading to absolute insulin deficiency, and includes latent autoimmune diabetes of adulthood; all forms of diabetes mediated by autoimmune β-cell destruction are included under the rubric of Type 1 diabetes.
Myth: Type 1 diabetes is a childhood disease.
Fact: Adults represent the majority of new-onset Type 1 diabetes; recent epidemiological data have shown that more than half of all new cases of type 1 diabetes occur in adults (R David Leslie et al. Adult-Onset Type 1 Diabetes: Current Understanding and Challenges. Diabetes Care 2021;44:2449-2456). Also, "Adult-onset type 1 diabetes is frequently misdiagnosed as type 2 diabetes, leading to inappropriate care. Emerging data suggest that up to 62% of type 1 diabetes cases develop after age 20 years" (Annals of Internal Medicine "Age at Diagnosis in U.S. Adults With Type 1 Diabetes," 26 September 2023).
Myth: We don’t know how to treat adult-onset type 1 diabetes/LADA.
Fact: Insulin is the correct treatment for people with Type 1 diabetes, according to a 2021 consensus report by the ADA/EASD: “Most people with Type 1 diabetes should use [insulin] regimens that mimic physiology as closely as possible, irrespective of the presentation.” Regarding adjunct therapies (metformin, pramlintide, GLP-1s, SGLT inhibitors), the authors state, “before these drugs are prescribed, insulin therapy should be optimized.” In other words, the initial treatment of a person with adult-onset Type 1 diabetes should not be to treat them as if they have Type 2 diabetes; the standard initial therapy is insulin (and then adjunct therapies can be considered). (The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) (Diabetes Care, September 30, 2021)).
Myth: You must have two or more positive autoantibodies to be classified as having type 1 diabetes.
Fact: Some doctors have claimed that a person must be positive for two or more autoantibodies, but that is a misinterpretation of the T1D TrialNet study (which excluded people over age 40). The TrialNet study was looking at the likelihood of people developing T1D, not diagnostic criteria. The ADA Standards of Care in Diabetes, Diagnosis and Classification of Diabetes, says that all forms of diabetes mediated by autoimmune beta cell destruction are included under the rubric of type 1 diabetes. From TrialNet's official webpage (where they are referring to people not yet in Stage 3 T1D): "If someone tests positive for one autoantibody, they are at increased risk of type 1 diabetes."
Myth: people with type 1 diabetes do not have detectable c-peptide.
Fact: From the American Diabetes Association/JDRF “Type 1 Diabetes Sourcebook,” (ADA/JDRF, 2013), “It is often unappreciated that many individuals with type 1 diabetes will have significant amounts of c-peptide, representing residual beta cell function. The standard teaching that T1D is defined as complete absence of beta cells is inaccurate and is a disservice to both patients and providers.”
Myth: a person must be in diabetic ketoacidosis (DKA) at presentation to have type 1 diabetes.
Fact: In the United States, about 30% of children are in DKA at diagnosis (70% NOT in DKA), and fewer adults (number unknown) are in DKA at diagnosis. From the National Institutes of Health (NIH), “Pediatric Diabetic Ketoacidosis,” Noha EL-Mohandes; Garrett Yee; Beenish S. Bhutta; Martin R. Huecker (2023), “DKA occurs at the time of diagnosis of type 1 diabetes in approximately 30 percent of children in the United States and Canada.” According to the ADA Standards of Care in Diabetes (2026), “adults [with new-onset T1D] may retain sufficient β-cell function to prevent DKA for many years.”
Myth: Slightly positive autoantibodies may not indicate type 1 diabetes.
Fact: The ADA Standards of Care in Diabetes, Figure 2.1 (2026) states that in a newly diagnosed adult with suspected type 1 diabetes, islet autoantibody positivity is classified as type 1 diabetes.
