Endocrine Abstracts

Introduction: Insulin resistance, often implicated in the pathophysiology of Type 2 Diabetes Mellitus, can also occur in patients with Type 1 Diabetes Mellitus (T1DM), giving rise to a distinct phenotype that some authors describe as Double Diabetes - a population with a higher risk of developing chronic complications. The estimated glucose disposal rate (eGDR) is a validated marker of insulin resistance in Type 1 Diabetes (T1DM), based on data obtained from the hyperinsulinemic-euglycemic clamp method. The eGDR formula uses common predictor variables in clinical practice: body mass index (BMI), glycated hemoglobin (HbA1c), and the presence of arterial hypertension (HTN). Insulin resistance is often reported as eGDR <8 mg/kg/min, and its relationship with macro-and microvascular complications is unclear. This study aims to investigate the relationship between eGDR and macro-and microvascular complications in T1DM patients from our Endocrinology – Diabetes outpatient clinic.

Methods: Patients with T1DM followed in the Endocrinology – Diabetes outpatient clinic were included, excluding those with hemoglobinopathies, pregnant individuals, and those with less than 5 years of disease duration. The eGDR was calculated using the formula: 19.02 - [0.22 × BMI (kg/m²)] - [(3.26 x HTN (0=absent; 1=present)] - [0.61 × HbA1c(%)]. Prevalences of complications and comorbidities were compared between insulin-resistant and insulin-sensitive groups, and odds ratios were calculated for three eGDR categories (<6; 6-7.99; ≥8 mg/kg/min), defined according to an observational study that related eGDR to mortality differences, whenever possible.

Results: A total of 182 individuals with T1DM were included, with 51% being male. The average age was 38.5 years, and the average disease duration was 18.5 years. Approximately 30.9% of the sample was overweight, and 12.6% had obesity. The eGDR was less than 8 mg/kg/min in about 44% of individuals, and this group was associated with the presence of at least one chronic complication of T1DM (OR 5.344 [95% CI 2.824–10.112], P-value<0.001). The eGDR inversely varied with the prevalence of microvascular complications, with statistical significance for diabetic kidney disease, diabetic retinopathy, and peripheral neuropathy. Due to the low prevalence of macrovascular complications in the sample, it was not possible to calculate statistically significant odds ratios.

Conclusions: The eGDR is a validated tool for estimating insulin resistance. It is associated with the prevalence of chronic complications of T1DM, making it a potentially helpful tool for personalized therapy in T1DM patients.