PLoS One. 2015 Jun 8;10(6):e0122248. doi: 10.1371/journal.pone.0122248. eCollection 2015.
Valuation of Normal Range of Ankle Systolic Blood Pressure in Subjects with Normal Arm Systolic Blood Pressure.
Gong Y1, Cao KW1, Xu JS1, Li JX1, Hong K1, Cheng XS1, Su H1.
Department of Cardiology, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China.
This study aimed to establish a normal range for ankle systolic blood pressure (SBP).
A 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 (90-139 mmHg).
Whether 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 (≥ 60 y) group. As the An-a on SBP was 13 mmHg in the young group and 20 mmHg 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.
A primary reference for normal ankle SBP was suggested as 100-165 mmHg in the young and 110-170 mmHg in the middle-elderly subjects.
The Bland-Altman plots for SBP between right ankle and arm in three age groups.
Y: the youth; M: the middle-aged; E: the elderly; SBPan: ankle SBP; SBPa: arm SBP.