Insulin resistance in type 1 diabetes: the silent burden unmasked by eGDR

Type 1 diabetes mellitus (T1DM) is primarily characterized by insulin deficiency; however, insulin resistance also contributes to poor metabolic outcomes and microvascular complications. The estimated glucose disposal rate (eGDR) is a simple, validated surrogate for insulin resistance. This study evaluated the utility of eGDR in predicting microvascular complications and metabolic syndrome (MetS) among Iraqi patients with type 1 diabetes mellitus (T1DM).

A cross-sectional study was conducted between November 2024 and July 2025 at the diabetic center in Baghdad Medical City and Al-Mustansiriyah University, a total of 263 adults with T1DM (> 1 year duration) were enrolled. Clinical, anthropometric, and biochemical parameters were collected, and eGDR was calculated. Participants were stratified into quartiles of eGDR. Logistic regression analysis and ROC analysis were performed to evaluate the predictive role of eGDR.

The mean age of participants was 25 ± 4.82 years, with an average diabetes duration of 8.62 ± 2.3 years. Suboptimal glycemic control was observed (HbA1c 9.11% ± 1.73). MetS was present in 36.9% of participants, while retinopathy, neuropathy, and nephropathy were detected in 4.6%, 5.7% and 4.6% respectively. Lower eGDR values were significantly associated with higher waist circumference, elevated HbA1c, and hypertension. eGDR independently predicted microvascular complications, with ROC analysis showing excellent discrimination for nephropathy (AUC 0.976), neuropathy (AUC 0.926), and retinopathy (AUC 0.914). The Predictive ability for MetS was moderate (AUC 0.731).

eGDR is a promising predictor of microvascular complications and MetS in T1DM.Its simplicity and low cost make it a practical clinical tool for early risk stratification, particularly in resource-limited settings.