Can augmentation index substitute aortic pulse wave velocity in the assessment of central arterial stiffness in type 1 diabetes?

The aim of this study was to test whether the augmentation index adjusted for heart rate (AIx@HR75) can be used as a substitute for aortic pulse wave velocity (aPWV) in the measurement of arterial stiffness (AS) in type 1 diabetes. Sixty-eight patients with type 1 diabetes and 68 age- and sex-matched controls were evaluated. AS was assessed by aPWV and AIx@HR75 using applanation tonometry. Subjects with type 1 diabetes had higher aPWV compared to controls, but no differences were found between groups regarding AIx@HR75 [men: 10.75 % (2.63-20.75) vs. 8.25 % (4.00-11.38); p = 0.462. Women: 20.75 % (5.00-30.16) vs. 14.50 % (11.38-22.16); p = 0.418]. In univariate analyses, aPWV correlated positively with AIx@HR75 in both groups (type 1: r = 0.340, p = 0.005; healthy subjects: r = 0.451, p < 0.001). However, AIx@HR75 was not associated with aPWV after adjustment for cardiovascular risk factors in multivariate models (type 1: p = 0.342; healthy subjects: p = 0.976). Our findings suggest that AIx@HR75 should not be used as a substitute for aPWV for measuring AS in type 1 diabetes.