C-Peptide Levels in Latent Autoimmune Diabetes in Adults Treated With Linagliptin Versus Glimepiride: Exploratory Results From a 2-Year Double-Blind, Randomized, Controlled Study

Latent autoimmune diabetes in adults (LADA) is a slowly progressing form of immune-mediated diabetes often misdiagnosed as type 2 diabetes because of its typical clinical presentation, i.e., an adult without weight loss or ketoacidosis not initially requiring insulin (1). Prior to insulin dependence, pharmacological options for reducing hyperglycemia comprise the oral glucose-lowering drugs used in type 2 diabetes; however, none has been established as the drug of choice in LADA because of the scarcity of evidence for or against the various agents (2). This study was a prespecified, exploratory analysis of a large ( n = 1,519) trial in which patients diagnosed with type 2 diabetes and HbA1c of 6.5–10.0% (48–86 mmol/mol) on metformin were randomized to additional once-daily linagliptin 5 mg or glimepiride 1−4 mg for 2 years (NCT00622284) (3). Fasting plasma samples taken during the study were tested for autoantibodies against GAD 65-kDa isoform (GAD65), islet cell cytoplasm, tyrosine phosphatase IA-2 (IA-2A), or insulin (IAA), and patients were classified as having LADA if positive for …