The Effect of Peripheral Pulse Arrival Time(PPAT) Measurement in Evaluating Endothelial Function: a Comparison with Flow-Mediated Vasodilation(FMD)

ABSTRACT

BACKGROUND AND OBJECTIVES: Endothelial dysfunction is an early change in the process of atherosclerosis. To evaluate endothelial function, expensive and specialized medical devices like high-resolution vascular ultrasound are necessary. Therefore, we sought to compare this atherosclerotic parameter of endothelial function using the inexpensive and simple method of peripheral pulse arrival time (PPAT) measurement. SUBJECTS AND METHODS: Before and after meals, we measured PPAT and flow-mediated vasodilation (FMD). Resting PPAT in both arms was measured with a PPAT device that was designed by the authors. Hyperemic effect was tested in both arms after raising the blood pressure to 250 mmHg for 5 minutes by using a blood pressure cuff, after which the cuff was released to 0 mmHg. PPAT was measured within the first 1 minute to observe the hyperemic response. FMD was measured in the same process by 7 MHz high-resolution ultrasound in the left brachial artery. The percent change was calculated from the baseline value and that of the hyperemic response. RESULTS: In low-fat diet, PPAT change was not different (3.8% vs. 4.7%, p>0.05). In high-fat diet, PPAT tended to be shorter, but without statistical significance (4.8% vs. 2.7%, p>0.05). In low-fat diet, the change of FMD was not different (11.7% vs. 11.4%, p>0.05). In high-fat diet, there was a significant difference in FMD (11.4% vs. 6.5%, p<0.05). CONCLUSION: The PPAT measurement could be a method for evaluating endothelial function, but is less sensitive than flow-mediated vasodilation.