Effects of Occlusion Cuff Pressures for Determining Brachial Artery Flow-Mediated Dilation in Healthy Thai Adults

Abstract

Variability in cuff occlusion pressure used during flow-mediated dilation (FMD) measurement may cause differences in FMD results and discomfort sensation. The objective of this study was to compare FMD data and sensations of pain and numbness using three levels of occlusion cuff pressures commonly used for FMD assessment in healthy adults. A within-subject design was conducted in 12 healthy adults aged 20-40 years. FMD was measured using brachial artery Doppler ultrasound at three different occlusion pressures: 25 and 50 mmHg above systolic blood pressure (SBP) and 200 mmHg. Pain and numbness were recorded using the Numeric Pain Rating Scale and the Visual Analog Scale, respectively, at baseline and every minute during the 5-minute occlusion and 3 minutes after cuff deflation. The results showed that %FMD and mean blood flow velocity after using cuff pressure at 25 mmHg above SBP (10.11 ± 2.58% and 11.52 ± 3.96 cm/s) were comparable to those of 50 mmHg above SBP (10.08 ± 2.70% and 12.54 ± 4.31 cm/s) and at 200 mmHg (10.15 ± 2.74% and 12.28 ± 4.30 cm/s) (all P >0.05). The pain intensity was significantly greater at 200 mmHg compared to 25 mmHg at the first, second, and fourth minutes during occlusion (all P <0.05). The numbness scale was not different among the three pressure conditions. In conclusion, the minimum occlusion pressure above SBP by 25 mmHg generated an insignificant FMD response compared to the other two cuff pressures, caused minor pain, and may be the favorable pressure for determining endothelium-dependent FMD in healthy Thai adults.