Latent autoimmune diabetes in adults

Background:Latent autoimmune diabetes in adults (LADA) is a relatively common form of autoimmune diabetes mellitus (DM) that is diagnosed based on the presence of DM-associated autoantibodies in patients who present with clinical features of type 2 DM.Objective:The goal of this article was to review the available data regarding LADA versus type 1 and type 2 DM, and the role of insulin in treating these diseases.Methods:Major English-language articles published since 1984 on autoimmune DM, including LADA and type 1.5 DM, were identified through a MEDLINE search on the topic.Results:The precise definition of LADA varies among investigators, but in addition to the presence of autoimmune markers, common elements of the definition have included disease onset in adulthood and the lack of an insulin requirement at diagnosis. The relevance of identifying LADA patients is primarily based on studies demonstrating a more aggressive clinical course in autoantibody-positive compared with autoantibody-negative individuals, with loss of β-cell function and progression to insulin dependence in most LADA patients soon after diagnosis. The commonalities between LADA and type 1 DM are not surprising, as these disease processes share similar immunogenetic features, which distinguish this population from patients with type 2 DM and from the general population. The LADA and type 2 DM populations can also be distinguished from each other based on clinical features. However, clinical features are not able to distinguish LADA from type 2 DM patients on an individual basis due to a large degree of overlap between the 2 groups. Therefore, the use of immunogenetic markers, in particular the measurement of autoantibodies, remains the gold standard for identifying these patients. The question remains as to whether identification of these patients is clinically relevant to their management. The early use of insulin resulted in β-cell preservation in several pilot studies; however, a much larger study found no beneficial effect of insulin on the prevention of type 1 DM onset in at-risk relatives.Conclusions:Screening recommendations await larger studies that will help elucidate the disease course of LADA, highlight the differences between LADA and type 1 or type 2 DM, and provide more information about the effects of intervention studies on this population.