Abstract 17013: The Reason Why Radial Augmentation Index is Low in Patients With Diabetes - The J-HOP Study -
Background: Radial augmentation index (AI), a marker of aortic wave reflection, is usually lower in patients with diabetes (DM) than in non-DM, despite the fact that atherosclerotic change is advanced in DM.
Objective: We sought to explore the reason why radial AI in DM is lower than non-DM.
Methods: We performed radial applanation tonometry in 1788 patients who had at least one cardiovascular risk factor in the J-HOP study. HOMA-R, a marker of the insulin resistance, was calculated by the standard equation. Radial AI was defined as [late systolic shoulder pressure amplitude (PP2)]/[radial pulse pressure (rPP)]. Central SBP and PP (cPP) were defined as the late systolic shoulder pressure (SBP2) and amplitude (PP2) of radial pressure wave. PP amplification defined as rPP/cPP.
Results: The mean age was 65.7±11.6 years; 47.4% were male; 436 (25.9%) patients of DM; and 87.7% had hypertension. The age and mean brachial SBP (141 vs. 141mmHg), were similar between the DM and non-DM groups. Radial AI was lower in the DM group, but clinic PP and cPP were higher in the DM group (Figure ). In multivariate linear regression analyses adjusting for age, sex, BMI, clinic SBP, the use of vasodilating drugs, beta-blockers, and insulin, significant determinants of radial AI were eGFR (beta=0.17, P<0.001) in the DM group, and log-transformed HOMA-R (beta=-0.15, P<0.001) in the non-DM group. The same trends were also seen for radial AI adjusted by HR 75bpm, central SBP and cPP in each group, respectively. The correlation coefficient between eGFR and radial AI was negative (r=-0.06; P=0.03) in the non-DM, whereas that was positive (r=0.13; P=0.006) in the DM group.
Conclusions: Lower radial AI in DM associated with higher cPP compared to non-DM suggests proximal conduit-predominant arterial stiffening causing reduced reflection coefficients at systemic reflection sites. As renal function decreases, a cPP increase may overcome the increase of augmentation pressure in the DM group.
- © 2013 by American Heart Association, Inc.