Latent autoimmune diabetes of adults is phenotypically similar to type 1 diabetes in a minority population.

Abstract

Latent autoimmune diabetes of adults (LADA) is a form of autoimmune diabetes that has been classified as part of type 1 diabetes or as a distinct clinical entity. Its precise place as a disease category is therefore controversial. The objective of this study was to further examine this issue by comparing the phenotypes of LADA and type 1 diabetes in a predominately minority population. We studied 126 subjects who were anti-glutamic acid decarboxylase antibody-positive in two separate studies--63 subjects in an outpatient study (study 1), and 63 inpatients after resolution of ketoacidosis (study 2). Clinical and biochemical phenotyping was performed in all patients in each group. Few significant differences were found in the clinical or biochemical phenotypes in patients classified as LADA when compared with type 1 diabetes. Adiposity, body mass index, waist/hip ratio, fasting plasma C-peptide, serum high-density lipoprotein cholesterol, and triglycerides were all similar. The only distinguishing feature was a history of hypertension (study 1) or systolic blood pressure (study 2). Also, a history of ketoacidosis did not influence the phenotype of LADA in the outpatients in any discernable way. We conclude that LADA and type 1 diabetes are phenotypically indistinguishable in this predominantly minority population with a mean duration of glutamic acid decarboxylase antibody-positive diabetes of about 8 yr.