1. ¹Department of Geriatric Medicine, Ehime University School of Medicine, Ehime, Japan
2. ²Department of Medical Genetics, Ehime University School of Medicine, Ehime, Japan
3. ³Omron Healthcare Company, Ltd., Kyoto, Japan

Correspondence: Dr. Katsuhiko Kohara, Department of Geriatric Medicine, Ehime University School of Medicine, Toon, Ehime 791-0295, Japan

Received 30 September 2004; Accepted 4 October 2004.

Abstract

Background: It has been shown that the systolic augmentation index (AI) in the central arteries, including the aorta and carotid arteries, changes with age. The AI can also be obtained from the peripheral arteries. The possible usefulness of AI obtained from the radial artery as an index for vascular aging was investigated.

Methods: Radial arterial waveforms were obtained from 632 subjects with no cardiovascular disease, using radial tonometry. Radial AI was calculated as follows: (Second peak systolic blood pressure [SBP2] - diastolic blood pressure [DBP]) / (first peak SBP - DBP) 100 (%).

Results: Radial AI was significantly higher in women than in men (81.1% 16.1% compared with 69.5% 16.3%, P < .001). Radial AI was positively related to age in healthy men and women (r = 0.619, P < .001, and r = 0.644, P < .001, respectively). When comparing subjects in their 20s to those in their 70s, radial AI increased 1.56 times (from 53.2% to 83.0%) in men and 1.49 times (from 64.6% to 96.4%) in women. Multiple regression analysis showed that age is a potent predictor of radial AI in addition to gender, DBP and pulse rate.

Conclusions: These findings indicate that simple and easily-obtainable radial AI is age-dependent and could be a useful index of vascular aging.