Latent Autoimmune Diabetes of Adult Masquerading as Type 2 Diabetes Mellitus

Abstract

Latent autoimmune diabetes of adults (LADA) is a slowly progressing subtype of type 1 diabetes mellitus (DM) that shares features of both type 1 and type 2 diabetes mellitus (T2DM), leading to its misdiagnosis and mismanagement. We present a case of a 30-year-old man who was diagnosed and managed as T2DM but later confirmed as a case of LADA. He was sent to the endocrinology clinic by his primary care physician for management of “uncontrolled T2DM”. He had been placed on glipizide and metformin, but was noted to have suboptimal blood glucose control and unintentional weight loss of about 20 - 30 lbs over a 3-month period. A diagnosis of LADA was confirmed by the presence of autoantibody to glutamic acid decarboxylase 65 (anti-GAD-65 antibody). His oral medications were discontinued and he was started on basal and mealtime insulin. It is important to identify LADA in adult patients thought to have T2DM, as these patients respond poorly to oral hypoglycemic drug therapy, require insulin and are at increased risk for developing ketoacidosis. Clinical presentation of LADA is often similar to T2DM, with diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) being uncommon complications. J Med Cases. 2015;6(7):327-329 doi: https://doi.org/10.14740/jmc2183w