Effect of static body and arm position on blood pressure in young healthy college students

Abstract

While interarm blood pressure differences have been regularly reported in older, diseased populations, it is not entirely known whether interarm BP differences exist in young, healthy populations. It is also well established that body and arm position influence BP measurements, but it isn't fully clear whether this observation holds true for both arms. The purpose of this study was to examine whether interarm BP differences exist in different static body and arm positions in young, healthy subjects. It was hypothesized that no interarm BP differences would be observed, independent of body and arm position. Young (20.4y/o; SD=1.20), college student subjects (n=18; 9 males; 9 females) had BP taken from both arms while standing, sitting, and supine, with arm parallel and perpendicular to the body. Respiratory rate was locked at 15-20bpm for each subject, and BPs were obtained 1 minute after the change in body or arm position. Subject mean body mass index was 27.5kg/m2 (SD=5.74) and all subjects were college athletes. No within arm differences in BP were observed for the right or left arm, independent of body and arm position. The left arm tended to have higher mean systolic BP when parallel (stand 149.2mmHg, SD=22.2; sit 140.5mmHg, SD=20.8; supine 134.6mmH, SD=19.1) or perpendicular (stand 129.5mmHg, SD=20.7; sit 124.2mmHg, SD=18.0) compared to the right arm mean systolic BP when parallel (stand 125.3mmHg, SD=12.6; sit 124.6mmHg, SD=9.8; supine 121.2mmHg, SD=10.7) or perpendicular (stand 113.6mmHg, SD=13.1; sit 110.3mmHg, SD=11.2). The left arm also tended to have higher mean diastolic BP when parallel (stand 88.2mmHg, SD=14.4; sit 79.4mmHg, SD=13.4; supine 74.1mmHg, SD=10.2) or perpendicular (stand 68.1mmHg, SD=11.6; sit 64.1mmHg, SD=11.3) compared to the right arm mean diastolic BP when parallel (stand 75.6mmHg, SD=8.3; sit 74.0mmHg, SD=8.8; supine 66.8mmHg, SD=8.8) or perpendicular (stand 64.8mmHg, SD=9.6; sit 60.1mmHg, SD=9.4). However, no statistically significant interarm BP differences were observed, independent of arm or body position. Heart rate tended to decline as subjects moved from standing (86.7bpm, SD=12.8) to sitting (75.9bpm, SD=10.3) to supine (66.4bpm, SD=7.6), but this was not statistically significant. The results of this study should be taken into consideration when obtaining BPs from young, healthy people. This is particularly important given the regular reporting of interarm BP differences in older, diseased populations. Future studies should examine whether interarm BP differences exist in older, diseased populations in different body and arm positions.