The prevalence of metabolic syndrome is significantly higher in patients with type 2 diabetes than in those with autoimmune diabetes.
Dr. Richard David G. Leslie, of the Institute of Cell and Molecular Science, London, UK, and colleagues explain in their paper that “autoimmune diabetes” includes type 1 diabetes as well as “adult-onset non-insulin-requiring diabetes,” also referred to as latent adult-onset autoimmune diabetes (LADA).
LADA is associated with histocompatability (HLA) genes, diabetes-associated autoantibodies, and reduced insulin secretion. Patients do not require insulin initially after diagnosis.
“The key question,” the researchers write, “is whether LADA is distinct from type 1 diabetes, that is, whether LADA is one end of a rainbow of pathophysiological variations encompassing autoimmune diabetes with a frequency of metabolic syndrome similar to that of childhood-onset type 1 diabetes, or whether LADA is a distinct form of autoimmune diabetes that resembles type 2 diabetes, showing evidence of insulin resistance with a high frequency of metabolic syndrome.”
To determine whether the prevalence of metabolic syndrome is associated with type of diabetes, the authors studied 2,011 subjects: 1,247 with type 2 diabetes without glutamic acid decarboxylase autoantibodies (GADAs), 117 diabetic patients with GADAs who had not received insulin for at least 6 months after diagnosis (LADA), 288 patients with type 1 diabetes, and 359 normal control subjects.
The frequency of metabolic syndrome was 31.9% in patients with type 1 diabetes, 41.9% in those with LADA, and 88% in type 2 diabetics.
When glucose was eliminated as a variable, the prevalence of metabolic syndrome was similar in subjects with autoimmune diabetes (17.3%) and control subjects (23.7%) but significantly higher in patients with type 2 diabetes (47.8%) (p=0.001 for all groups).
“Whether glucose was or was not used as a variable, we found that individual components of the metabolic syndrome in both patients with type 1 diabetes and those with LADA were similar but in each group were less than those seen in type 2 diabetic patients,” Dr. Leslie’s team notes.
They add, “There is no evidence from this data set that autoimmune diabetes is distinct in terms of prevalence of metabolic syndrome from that in normal subjects, and the hypothesis that it would be distinct is rejected.”
Diabetes Care 2009;32:160-164.