6-OR: Estimated Glucose Disposal Rate and Major Vascular Events in Type 1 Diabetes: A 10-Year Follow-Up Study

Estimated Glucose Disposal Rate (eGDR), a validated tool to estimate insulin sensitivity (IS) in T1DM [eGDR = 21.158 - (0.09 x WC, cm) - (3.47 x hypertension, yes = 1) - (0.551 x HbA1c, %)], has been associated to all-cause death. The relationship between eGDR and major vascular (CV) events was evaluated in 736 T1DM enrolled in an observational, single-centre study over a 10-year follow-up. Incidence of CV and coronary events were obtained by interrogating hospital discharge registers. Mean eGDR was 7.51±2.26 (M±SD) mg/kg/min (median 8.26; IQR 5.53-9.29). According to the “Swedish National Diabetes Register,” eGDR was stratified in: C1: ≥8.0 (N. 399, 54.2%, ref); C2: 6.0-7.99 (N. 121, 16.4%); C3: 4.0-5.99 (N. 144, 19.6%) and C4: <4.0 mg/kg/min (N. 72, 9.8%). Compared to C1, C2-4 showed a worse risk profile. A total of 49 CV events (defined as first of MI, stroke, coronary, carotid or peripheral revascularization) occurred over a follow-up of 10.38±2.88 years (6.7%, 6.42 x1000 PYs). By Kaplan-Meier, incidence increased across eGDR categories: C1, 2.3%; C2, 4.1% (HR [95% CI] 1.79 [0.60-5.35]); C3, 11.8% (5.68 [2.53-12.75]); C4, 25.0% (12.76 [5.73-28.43], p<0.0001). After adjustment for multiple confounders, risk of CV events was significantly increased in C4 (5.18 [2.11-12.72], p<0.0001). Further adjustment for variables strictly related to IS (HDL, triglycerides, ACR) did not exclude C4 eGDR as an independent covariate. Over a follow-up of 10.47±2.74 years, 35 coronary events (first of MI or coronary revascularization) occurred (4.8%; 4.54 x 1000 PYs). Incidence increased across eGDR categories: C1, 2.3%; C2, 0.8% (0.35 [0.04-2.76]); C3, 7.6% (3.65 [1.51-8.81]); C4, 19.4% (9.64 [4.17-22.30], p<0.0001). After adjustment for multiple confounders, risk of coronary events was significantly increased in C4 (4.78 [1.90-12.04], p=0.001). Even so after further adjustment for variables strictly related to IS. Thus, in our T1DM, eGDR was a long-term independent predictor of vascular events.