Blood pressure variability between radial artery and finger is influenced by haemodynamic factors, age and insulin resistance.

摘要

BACKGROUND: In clinical practice, blood pressure (BP) is typically assessed using brachial measurements, whereas finger plethysmography is widely used in vascular physiology research. However, agreement between BP levels at the finger and more proximal sites is not straightforward because of interindividual differences in BP gradients along the arterial tree. METHODS: We investigated factors associated with the mean arterial pressure (MAP) difference between non-invasive radial artery and finger measurements in 574 normotensive and hypertensive individuals without cardiovascular disease, diabetes or antihypertensive medication. Recordings included pulse wave analysis from radial BP, plethysmographic finger BP and whole-body impedance cardiography. Radial BP signals were calibrated using oscillometric contralateral brachial artery measurements. RESULTS: Simultaneous mean radial and finger BP (systolic/diastolic) were 131/75 and 122/69 mmHg, respectively (p < .001). When examined in quartiles of the radial-finger BP gradient, the average MAP difference was -7, 4, 10 and 20 mmHg, respectively. In linear regression analysis (enter method), a greater MAP difference was significantly associated with higher radial MAP (p < .001), age (p = .001) and stroke index (p = .015); and with lower pulse wave velocity (p < .001), pulse pressure amplification (p = .002) and insulin sensitivity check index (p = .022). CONCLUSIONS: High MAP is a major factor contributing to greater BP difference between the radial and finger sites. However, the difference is also more pronounced in the presence of lower large artery stiffness, lower pulse pressure amplification, and higher stroke index, older age and greater insulin resistance. Blood pressure (BP) is a crucial measure in both clinical practice and research. Continuous BP monitoring using finger-based devices is increasingly used, but measurements from the finger may differ from those taken closer to the heart or at more central arteries. Previous research has shown that BP measured at the radial artery at the wrist is often higher than BP measured at the finger, indicating systematic differences between sites and methods.We examined 574 adults without diagnosed cardiovascular disease, diabetes or BP medication to identify physiological and metabolic factors that explain why finger-derived BP differs from radial artery measurements.BP was recorded simultaneously and non-invasively at the radial artery and at the finger. In addition, detailed measurements of cardiac function, arterial properties and metabolic markers were performed.Finger BP was generally lower than radial artery BP. The difference varied widely between individuals. Larger differences were associated with higher arterial BP, age and stroke volume; and with lower large arterial stiffness, pressure transmission towards the periphery and lower insulin sensitivity.Many continuous BP monitoring systems use finger cuff technologies based on volume-clamp/plethysmography methods. While very useful, these do not provide values identical to more central arterial measurements. Finger BP devices are valuable tools for continuous monitoring. However, the results should be interpreted with some caution when precise BP estimation is crucial.