• Vol. 43 No. 2, 107–112
  • 15 February 2014

Comparison of Adults with Insulin Resistance (IR) in Latent Autoimmune Diabetes Versus IR in Glutamic Acid Decarboxylase Antibody-negative Diabetes



Introduction: Insulin resistance in latent autoimmune diabetes in adults (LADA) patients is controversial. The aim of this study was to evaluate insulin resistance and its related factors (metabolic syndrome parameters) among subjects with LADA and glutamic acid decarboxylase antibodies (GADA) negative diabetes, as well as the impact of these factors on insulin resistance.

Materials and Methods: GADA levels were investigated in 1140 diabetic patients aged between 30 and 70 years. Insulin resistance and metabolic syndrome parameters were assessed in LADA and GAD-negative diabetic patients by general linear model. In addition, the impact of metabolic syndrome factors on insulin resistance was assessed in LADA and glutamic acid decarboxylase (GAD)-negative diabetic patients.

Results: LADA was diagnosed in 33 subjects from 1140 Malaysian diabetic patients (prevalence = 2.9%). The results showed that LADA patients had higher insulin resistance and high density lipoprotein cholesterol (HDLc) (P = 0.003 and 0.00017 respectively) and lower body mass index (BMI) (P = 0.007) compared to GAD-negative diabetic patients. The HDLc was associated with decreased insulin resistance in LADA patients (P = 0.041), whereas HbA1c, triacylglycerides (TG) and waist were associated with increased insulin resistance in GAD-negative diabetic patients (P = 3.6×10-12, 1.01×10-5 and 0.004 respectively). HbA1c was highly associated with decreasing β-cell function in both LADA (P = 0.009) and GAD-negative diabetic subjects (P = 2.2×10-28).

Conclusion: Insulin resistance is significantly higher in LADA than GAD-negative diabetic Malaysian subjects.

Latent autoimmune diabetes in adults (LADA) is a term used to describe the adult onset autoimmune diabetes, characterised by the presence of type 1 diabetes-associated antibodies but has a slower progression toward an absolute insulin requirement. LADA is characterised by autoimmune destruction of pancreatic β cells with the presence of T-cell reactivity to circulating auto-antibodies, more frequently, glutamic acid decarboxylase antibodies (GADA). GADA is the most sensitive marker for LADA. Recent studies showed that GADA titers have a bimodal distribution in LADA and identify 2 subgroups of patients with distinct clinical, autoimmune and genetic features. Patients with high GADA titers tend to be younger, leaner and have a lower prevalence of metabolic syndrome and its components, with more prominent traits of insulin deficiency (lower C-peptide, higher HbA1c) than individuals with lower GADA titers. Epidemiological studies showed that LADA prevalence among T2D varies from 2% to 12% and tends to be higher in Western countries compared to Asian countries. Prevalence of LADA has not been studied in Malaysia, which has a multiethnic population including Malays (50.4%), Chinese (23.7%) and Indian (7.1%). These 3 ethnic groups represent the major portion of the population residents in Asia.

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