Valuation of Normal Range of Ankle Systolic Blood Pressure in Subjects with Normal Arm Systolic Blood Pressure

Abstract

SubjectThis study aimed to establish a normal range for ankle systolic blood pressure (SBP).MethodsA total of 948 subjects who had normal brachial SBP (90-139 mmHg) at investigation were enrolled. Supine BP of four limbs was simultaneously measured using four automatic BP measurement devices. The ankle-arm difference (An-a) on SBP of both sides was calculated. Two methods were used for establishing normal range of ankle SBP: the 99% method was decided on the 99% reference range of actual ankle BP, and the An-a method was the sum of An-a and the low or up limits of normal arm SBP (90–139mmHg).ResultsWhether in the right or left side, the ankle SBP was significantly higher than the arm SBP (right: 137.1±16.9 vs 119.7±11.4 mmHg, P<0.05). Based on the 99% method, the normal range of ankle SBP was 94~181 mmHg for the total population, 84~166 mmHg for the young (18–44 y), 107~176 mmHg for the middle-aged(45–59 y) and 113~179 mmHg for the elderly (≥60y) group. As the An-a on SBP was 13mmHg in the young group and 20mmHg in both middle-aged and elderly groups, the normal range of ankle SBP on the An-a method was 103–153 mmHg for young and 110–160 mmHg for middle-elderly subjects.ConclusionA primary reference for normal ankle SBP was suggested as 100-165 mmHg in the young and 110-170 mmHg in the middle-elderly subjects.

Defining the relationship between arm and leg blood pressure readings

“…Subgroup and sensitivity analyses by cardiovascular disease history, cardiovascular disease risk, measurement method/device and methodological quality did not sufficiently explain the observed variation, although exclusion of studies not using auscultation or a validated upper arm device did reduce some the observed heterogeneity, suggesting this may have been a contributing factor. Although age has previously been shown to affect the magnitude of arm-ankle blood pressure difference, [5] meta-regression by age revealed no such association in the present data. Other factors contributing towards the observed heterogeneity might include the blood pressure device and model used, number of readings taken and the observer making the measurement (e.g.…”

“…[10][11][12][13][14] Few studies have set out to measure the arm-leg blood pressure difference in the general population to aid interpretation of leg measurements in clinical practice. One study by Gong et al, [5] showed in 948 patients that blood pressure was 17.4 mmHg (95% CI 16.7 to 18.1 mmHg) higher when measured in the ankle than when measured in the arm, findings which are consistent with the present review. Implications for clinical practice Current clinical guidelines pay little attention to measurement of blood pressure in the leg and there is no guidance on the most appropriate method of measurement.…”

“…Generally, older studies used Doppler probes and strain-gauge plethysmography techniques. [15][16][17][18][19] Newer studies using validated oscillometric sphygmomanometers found similar arm-leg blood pressure differences to those using other devices [4,5,10], although the statistical heterogeneity across studies was reduced. When measuring armleg blood pressure differences, for example in the assessment of peripheral vascular disease, the present data suggest similar differences can be observed using sequential versus simultaneous methods.…”

“…A number of previous studies have compared blood pressure readings made in the leg to those in the upper arm. [4][5][6] However, these studies have examined different populations using varying measurement techniques, so it is unclear what standard blood pressure difference between upper and lower limbs should be expected. It is also unclear how diagnostic and treatment thresholds should be adjusted when leg blood pressure measurements are relied upon to guide treatment.…”

Screening, Sensitivity, Specificity, and So Forth: A Second, Somewhat Skeptical, Sequel

“…When ankle blood pressure is divided by brachial blood pressure, the single-figure outcome is known as the anklebrachial index, or ABI. For a healthy person, ankle pressure is typically higher than brachial pressure (Goldstein et al, 2014;Gong et al, 2015;Xu et al, 2010), (Note 2) and therefore the ABI is likely to be > 1.0, often in the range 1.1 to 1.3. In a person with PAD, the ABI is, at least theoretically, likely to be noticeably < 1.0, and an ABI ≤ 0.90 is often regarded as indicative of PAD (Bundó et al, 2013;Xu et al, 2010).…”