GeeHee Kim,1 Ji-Hoon Kim,1 Keon-Woong Moon,1 Ki-Dong Yoo,1 Sang-Hyun Ihm,2 Ho-Joong Youn,2 Chul-Min Kim11Division of Cardiology, Department of Internal Medicine, St Vincent's Hospital, Catholic University of Korea, Suwon, 2Division of Cardiology, Department of Internal Medicine, School of Medicine, Catholic University of Korea, Seoul, South KoreaObjective: Diastolic dysfunction is associated with increased arterial stiffness in patients with hypertension. However, the role of arterial stiffness in diastolic dysfunction in subjects without hypertension has not been fully established.Materials and methods: A total of 287 subjects (male:female ratio 121:166, mean age 53.0±14.4 years) without hypertension or any heart disease who simultaneously received transthoracic echocardiography and noninvasively semiautomated radial artery applanation tonometry (with an Omron HEM-9000AI) in the Department of Internal Medicine, St Vincent’s Hospital, from July 2011 to September 2012, were enrolled in this study.Results: A total of 147 subjects (male:female ratio 59:88, mean age 61.7±9.9 years), representing 51.2% of the 287 subjects, had diastolic dysfunction (defined as abnormal relaxation pattern of mitral inflow). There were significant differences in systolic blood pressure (BP), pulse pressure, late systolic peak pressure (SBP2), and radial augmentation index (RaAIx) between normal diastolic function and diastolic dysfunction. ΔBP was defined as systolic BP minus SBP2, because of the difference in systolic BP between the two groups. ΔBP (odds ratio [OR] 1.059, 95% confidence interval [CI] 1.005–1.115; P=0.032) and RaAIx (odds ratio 1.027, 95% CI 1.009–1.044, P=0.003) were associated with diastolic dysfunction. A receiver operating-characteristic curve showed that ΔBP (area under the curve 0.875, 95% CI 0.832–0.911) and RaAIx (area under the curve 0.878, 95% CI 0.835–0.914) were associated with diastolic dysfunction.Conclusion: We found that ΔBP and increased RaAIx were associated with diastolic dysfunction in subjects without hypertension after adjustment for age and sex. Therefore, it is suggested that noninvasive estimation of central BP may be useful to reflect diastolic dysfunction in subjects with normal peripheral BP.Keywords: central blood pressure, augmentation index, diastolic dysfunction