Insulin resistance and abdominal adiposity discriminate early vascular aging (higher vascular risk) in adults with type 1 diabetes without cardiovascular events

AIMS: Adults with type 1 diabetes (T1D) and early vascular aging (EVA; higher arterial stiffness) are at increased risk for vascular complications and all-cause mortality. Because insulin resistance (IR) may promote arterial stiffness, we investigated this association and its potential to discriminate EVA. METHODS: Adults with T1D without cardiovascular events were assessed for arterial stiffness (aortic pulse wave velocity [aPWV]) and IR (by estimated insulin sensitivity [eIS] using a validated equation incorporating hypertension, HbA1c and waist-to-hip ratio [WHR]). Additional measures of abdominal adiposity (waist circumference [WC], waist-to-height ratio [WHtR]) were also analyzed. EVA definition: aPWV > 10 m/s. RESULTS: Among 179 participants (48.6 % female, aged 41.2[13.1] years, disease duration 16[12-23] years, aPWV (7.1[6.1-8.4] m/s, -18 with EVA-, eIS (8.59[6.12-10.00] mg/kg/min)), an independent association between eIS and aPWV was found (ß=-0.218, P < 0.001), mainly driven by WHR (P < 0.001). eIS (cutoff:<7.10 mg/kg/min, C-statistic 0.77[0.66-0.88]) and WHR (cutoff:>0.93, C-statistic 0.77[0.66-0.88]) performed similarly (P = 1.000) in discriminating EVA, whereas eIS was outperformed by both WC (cutoff:>90.8 cm, C-statistic 0.87[0.81-0.93] P = 0.025) and WHtR (cutoff:>0.56, C-statistic 0.91[0.85-0.96] P = 0.011). CONCLUSIONS: In adults with T1D without cardiovascular events, higher IR is associated with vascular aging driven by abdominal adiposity. Simple measures of abdominal adiposity (WHtR, WC) effectively discriminate those adults with EVA.