Body position and blood pressure measurement in patients with diabetes mellitus

AIMS: World Health Organization (WHO) guidelines recommend that the blood pressure (BP) should be routinely measured in sitting or supine followed by standing position, providing that the arm of the patient is placed at the level of the right atrium in each position. The aim of our study was to test the influence of body and arm position on BP measurement in diabetic patients. METHODS: In 142 patients with diabetes mellitus the BP was measured using a semiautomatic oscillometric device (Bosomat-R): (i) after 5 min of rest sitting on a chair with one arm supported at the right atrial level and with the other arm placed on the arm support of the chair, (ii) after 5 min of rest lying on a bed with both arms placed on a bed, and (iii) after 30 s and after 2 min of standing with one arm (the same as in sitting position) supported at the right atrial level and with the other arm vertical, parallel to the body. RESULTS: Both systolic (SBP) and diastolic (DBP) blood pressures were significantly lower in sitting position with the arm at the right atrial level than in supine position (by 7.4 and 6.6 mmHg, respectively, P < 0.01). In sitting and standing positions, SBP and DBP were higher when the arm was placed either on the arm support of the chair or vertical, parallel to the body, than when the arm was supported at the level of the right atrium (by 6-10 mmHg, P < 0.001). Duration of standing did not influence the estimation of orthostatic hypotension. CONCLUSIONS: The data of this study indicate that the WHO recommendation with regard to the equivalence of sitting and supine BP readings is incorrect at least in diabetic patients, as the sitting BP is lower than the supine BP when the arm was positioned at the right atrial level. In addition, incorrect positioning of the arm in standing position results in an underestimation of prevalence of orthostatic hypotension. We conclude that during BP measurement the arm should be placed at the right atrial level regardless of the body position.     

Arm position and blood pressure: a risk factor for hypertension?

The objective of this study was to re-evaluate the effect of arm position on blood pressure (BP) measurement with auscultatory and oscillometric methods including ambulatory blood pressure monitoring (ABPM). The setting was the hospital outpatient department and the subjects chosen were normotensive and hypertensive. The effect of lowering the arm from heart level on indirect systolic BP (SBP) and diastolic BP (DBP) measurement as well as the importance of supporting the horizontal arm were measured. In the sitting position, lowering the supported horizontal arm to the dependent position increased BP measured by a mercury device from 103+/-10/60+/-7 to 111+/-14/67+/-10 mmHg in normotensive subjects, a mean increase of 8/7 mmHg (P<0.01). In hypertensive subjects, a similar manoeuvre increased BP from 143+/-21/78+/-17 to 166+/-29/88+/-20 mmHg, an increase of 23/10 mmHg (P<0.01). Combined results from normotensive and hypertensive subjects demonstrate a direct and proportional association between BP (SBP and DBP) and the increase produced by arm dependency. Similar changes and associations were noted with oscillometric devices in the clinic situation. However, supporting the horizontal arm did not alter BP. Of particular interest, analysis of 13 hypertensive subjects who underwent ABPM on two occasions, once with the arm in the 'usual' position and once with the arm held horizontally for BP measurement during waking hours, demonstrated changes comparable to the other devices. The mean 12-hour BP was 154+/-19/82+/-10 mmHg during the former period and significantly decreased to 141+/-18/74+/-9 mmHg during the latter period (P<0.01). Regression analysis of the change in SBP and DBP with arm position change again demonstrated a close correlation (r(2)=0.8113 and 0.7273; P<0.001) with the artefact being larger with higher systolic and diastolic pressures. In conclusion, arm movements lead to significant artefacts in BP measurement, which are greater, the higher the systolic or diastolic pressure. These systematic errors occur when using both auscultatory and oscillometric (clinic and ABPM) devices and might lead to an erroneous diagnosis of hypertension and unnecessary medication, particularly in individuals with high normal BP levels. Since clinical interpretations of heart level vary, the horizontal arm position should be the unambiguous standard for all sitting and standing BP auscultatory and oscillometric measurements.     

Both body and arm position significantly influence blood pressure measurement

The position of both the body and the arm during indirect blood pressure (BP) measurement is often neglected. The aim of the present study was to test the influence of the position of the patient on BP readings: (1) sitting with the arms supported precisely at the right atrium level and (2) supine: (a) with the arms precisely at the right atrium level and (b) with the arms on the examination bed. In a first group of 57 hypertensive patients, two sessions of BP and heart rate (HR) measurements were performed in two positions: sitting and supine with the arms supported precisely at right atrium level in both positions. BP was measured simultaneously at both arms, with a Hawksley Random Zero sphygmomanometer at the right arm, and with an automated oscillometric device (Bosomat) at the left arm. BP and HR readings obtained in the two positions were then compared. In a second group of 25 normo- and hypertensive persons, two sessions of BP and HR readings were performed in supine with the arms in two different arm positions: (a) the arm placed precisely at right atrium level and (b) the other arm on the examination bed. The measurements were performed at both arms with two automated devices (Bosomat). The readings taken in the two positions were compared. Both systolic BP (SBP; by 9.5 +/- 9.0 (standard deviation, s.d.); right arm) and diastolic BP (DBP; by 4.8 +/- 6.0 mmHg; right arm) were significantly higher in the supine than in the sitting position. When the two different arm positions (body continously supine) were compared in the second part of the study, significantly higher SBP (by 4.6 +/- 6.1 mmHg) and DBP (by 3.9 +/- 2.8 mmHg) were obtained when the arm of the patient was placed on the bed (below the right atrium level), than when the arm was placed at the level of the right atrium. BP readings in sitting and supine positions are not the same. When according to guidelines the arm of the patient is meticulously placed at the right atrium level in both positions, the difference is even greater than when the arm rests on the desk or on the arm support of the chair. Moreover, in the supine position small but significant differences in BP are measured between arm on a 5 cm-high pillow and arm on the bed. In every study reporting BP values, the position of both the body and especially the arm should be precisely mentioned.     

Blood pressure variations from clinostatism to orthostatism

The reactivity of blood pressure (BP) and heart rate (HR) to change from supine to standing position was examined in 257 healthy adults, adolescents and children divided into equivalent group of both sexes. BP and HR were measured every minute during 14 minutes in a supine position then during 5 minutes in a standing position with an automatic device using the oscillometry method. A second measurement session was repeated two weeks later. On most patients an increase of diastolic BP (7.73 +/- 4.34 mmHg) and HR (16.40 +/- 7.47/mn) was observed after standing whereas systolic BP modifications were inconstant (2.19 +/- 5.55 mmHg). A comparison of variability indices according to postural state showed a significant higher variability index in a standing position only in female subjects. There was no difference according to age groups. Reproducibility of diastolic BP and HR increase is good two weeks later in respectively 65 p. 100 and 80 p. 100 subjects but it appears very poor for systolic BP. The results in healthy subjects would be compared to those observed in hypertensives to determinate if a postural change test may provide a clinical simple way to discriminate abnormalities in blood pressure regulation.     

How does deep breathing affect office blood pressure and pulse rate?

Little is known about the relation between deep breathing (DB) and blood pressure (BP). We studied the relationship between DB and BP in a large Japanese population. The subjects were recruited from randomly selected clinics and hospitals that were members of a medical association, and divided into two groups. In one group, BP was measured before and after taking 6 DB over a period of 30 s, and in the other group BP was measured before and after a 30-s rest in a sitting position without DB. Before these measurements, all patients rested 10 min or more in the waiting room and another 2 min or more in the doctor's office. Analyses were performed on data collected from 21,563 subjects. In both groups, systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse rate (PR) were significantly reduced after DB or a 30-s rest compared with the baseline measurements (p < 0.001). SBP reductions were greater in the DB group than in the 30-s rest group (normotensives: -6.4 +/- 8.3 vs. -3.0 +/- 7.4 mmHg, p < 0.001; untreated hypertensives: -9.6 +/- 10.2 vs. -5.9 +/- 9.1 mmHg, p < 0.001; treated hypertensives: -8.3 +/- 9.6 vs. -4.4 +/- 8.3 mmHg, p < 0.001). Greater BP reductions were found in patients with a higher baseline BP in both the DB and 30-s rest groups. In conclusion, the present study showed a baseline BP-dependent BP reduction by DB, suggesting that BP measurement should be done without DB in the office because DB lowers BP.     

Altered aortic properties in elderly orthostatic hypertension.

To investigate the impact of arterial properties on orthostatic blood pressure (BP) dysregulation in older hypertensives, orthostatic BP dysregulation, a common phenomenon in elderly hypertensives, is associated with target organ damage and falls. However, the mechanism of orthostatic BP dysregulation remains unclear. The pulse wave velocity (PWV), related arterial stiffness, and the augmentation index (AI), a measure of arterial wave reflection, were measured in 365 older hypertensives. We classified the study patients into an orthostatic hypertension (OHT) group with orthostatic increase of systolic BP (SBP) of > or = 220 mmHg (n = 27) and an orthostatic normotension (ONT) group with an orthostatic increase of SBP of < 20 mmHg and orthostatic SBP decrease of < 20 mmHg (n = 338). Orthostatic AI was significantly greater in the OHT group than in the ONT group (OHT: 6.5 +/- 12% vs. ONT: -5.6 +/- 12%, p < 0.001), while supine AI and supine and orthostatic pulse rate were comparable between the two groups. There was no significant difference in the PWV between the OHT and ONT groups. Orthostatic hypertension was affected by altered aortic properties and associated with augmented wave reflection of arterial pressure.     

Validation of a wrist‐type home nocturnal blood pressure monitor in the sitting and supine position according to the ANSI/AAMI/ISO81060‐2:2013 guidelines: Omron HEM‐9601T

This study aimed to validate the accuracy of the Omron HEM‐9601T, an automatic wrist‐type device for self‐blood pressure (BP) measurement with a timer function for automatic measurement of nocturnal BP, in the sitting position according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060‐2:2013 guidelines, and to assess its performance in the supine position by applying the same protocol as conducted in the sitting position. The mean differences between the reference BPs and HEM‐9601T readings were 1.2 ± 6.9/1.1 ± 5.5 mmHg, 2.2 ± 6.5/1.8 ± 5.7 mmHg, 0.1 ± 6.6/1.5 ± 6.2 mmHg, and ?0.8 ± 7.2/0.5 ± 6.4 mmHg for systolic BP/diastolic BP for criterion 1 in the sitting position, supine with sideways palm position, supine with upward palm position, and supine with downward palm position, respectively. In addition, the mean differences and their standard deviations for systolic BP and diastolic BP calculated according to criterion 2 in the ANSI/AAMI/ISO 81060‐2:2013 guidelines were acceptable in all four positions. In conclusion, the Omron HEM‐9601T fulfilled the validation criteria of the ANSI/AAMI/ISO81060‐2:2013 guidelines when used in the sitting position with the wrist at heart level, and its accuracy in the supine position was acceptable and roughly equivalent to that in the sitting position. The wrist‐type home BP monitor could be a more suitable tool for repeated nocturnal BP measurements at home than upper‐arm devices, and could improve the reliability of diagnosis and management of nocturnal hypertension.     

Influence of different supine body positions on blood pressure: consequences for night blood pressure/dipper-status

OBJECTIVES: To investigate the influence of different supine body positions on blood pressure measured by an ambulatory device. DESIGN AND METHODS: Twenty hypertensive and 20 normotensive subjects of a tertiary hospital outpatient clinic participated. Blood pressure was measured with an ambulatory blood pressure device while lying in the back, left side, right side and abdominal positions. The distance between the antecubital fossa and sternum was measured in all four body positions. An expected blood pressure difference between the arm of measurement and the right atrium (i.e. the midsternum) was calculated for the different body positions. RESULTS: When blood pressure was measured in side position at the left arm in hypertensive subjects, the mean systolic and diastolic blood pressure differences (+/- SD) between the left arm in the lower position and in back position at the same arm were +5/+4 (8/6) mmHg. These differences were -14/-17 (6/4) mmHg for the left arm lying above heart level in side position. Values of the right arm in hypertensives and the measurement at both arms in normotensive subjects yielded similar differences. CONCLUSIONS: Body and arm position can both significantly influence the ambulatory blood pressure and therefore the day-night difference. This comprises one of the main reasons for the moderate individual reproducibility of the blood pressure fall at night.     

Blood pressure response during maximal exercise in apparently healthy men and women

The blood pressure (BP) response during a maximal ergometer bicycle test was studied in 190 apparently healthy subjects (95 men and 95 women) aged 21-70 years. The starting load was 50 W and was increased by 50 W every 4 min until exhaustion. Mean physical performance expressed as cumulative work was 2276 +/- 789 W in men and 1109 +/- 276 W in women (P less than 0.0001). The maximum heart rate was similar in men and women and declined significantly with age (r = -0.78, P less than 0.001 for men and r = -0.64, P less than 0.0001 for women). The mean maximal systolic blood pressure (MSBP) was 193 +/- 23 mmHg in men and 171 +/- 21 mmHg in women (P less than 0.0001). Men aged greater than or equal to 50 years had a MSBP of 201 +/- 22 mmHg, compared to 188 +/- 22 mmHg in those aged less than 50 years (P less than 0.01). Women aged greater than or equal to 60 years had a MSBP of 190 +/- 21 mmHg compared to 166 +/- 19 mmHg in their younger counterparts (P less than 0.001). The diastolic BP showed a similar modest increase at all ages and in both sexes. SBP is dependent on age and gender and this must be taken into consideration when assessing a normal response in individual patients.     

Postprandial hypotension predicts all-cause mortality in older, low-level care residents

OBJECTIVES: To evaluate which indices of blood pressure (BP) homeostasis are the strongest predictors of mortality in older low-level-care residents in long-term health facilities. DESIGN: Prospective cohort study. SETTING: Eight long-term healthcare facilities in Canberra, Australia. PARTICIPANTS: A total of 179 randomly selected semi-independent residents aged 65 and older (mean age+/-standard deviation 83.2+/-7.0; 80% women). MEASUREMENTS: Baseline BP levels taken while lying, after standing for 1 and 3 minutes, and sitting before and 1 hour after meal intake were recorded, as well as demographic information, chronic medical conditions, medications, and all-cause mortality during follow-up. Postprandial hypotension (PPH) was defined as a fall in systolic BP (SBP) of 20 mmHg or more 1 hour postmeal while sitting. Orthostatic hypotension (OH) was defined as a fall in SBP of 20 mmHg or more or in diastolic BP (DBP) of 10 mmHg or more within 3 minutes of standing from a supine position. Hypertension was defined as BP greater than 160/90 mmHg at commencement of the study. Mean arterial pressure (MAP) and pulse pressure (PP) were calculated. RESULTS: At baseline, 47% of participants had hypertension, 38% PPH, and 23% OH; PP was 70 mmHg or greater in 54%, and DBP was 65 mmHg or lower in 6%. Over 4.7 years, 97 (54%) participants died. Those who died were significantly older and more likely to have PPH (47% vs 28%) and atrial fibrillation (35% vs 17%) and a significantly greater decrease in BP after meal intake. Mortality rates in those with and without PPH were 145.0 and 98.5 per 1,000 person-years, respectively. Using multivariate Cox proportional hazards models after adjustment for age, sex, presence of atrial fibrillation, Parkinson's disease, and use of diuretics, PPH was the only BP parameter that significantly and independently predicted 4.7-year all-cause mortality (relative risk (RR)=1.79; 95% confidence interval (CI)=1.19-2.68; P=.005). Further adjustment for the presence of OH, hypertension, low resting BP, coronary artery disease, cerebrovascular disease, congestive heart failure, history of syncope, cognitive impairment, cancer, diabetes mellitus, chronic obstructive pulmonary disease, and history of smoking did not reveal any new statistically significant associations. There was a dose-response relationship between postprandial fall in SBP and mortality rates. Absolute postprandial SBP of 120 mmHg or less was also significantly associated with total mortality (RR=1.69, 95% CI=1.04-2.78; P=.04). Low DBP was also associated with increased mortality (RR=1.10, 95% CI=1.01-1.13; P=.03), although this association became nonsignificant in multivariate analysis. CONCLUSION: In older low-level-care residents, PPH is an independent predictor of all-cause mortality with no added predictive value explained by other BP indices: OH, hypertension, PP, MAP.     

Office blood pressure underestimates ambulatory blood pressure in peripheral arterial disease in comparison to healthy controls

Patients with peripheral arterial disease (PAD) constitute a subgroup of high-risk hypertensives, but controlled studies on 24-h blood pressure (BP) and diurnal variation of BP are lacking. This study was performed in order to test the hypothesis that office BP (OBP) may underestimate 24-h BP in PAD patients in comparison to a matched control group. In all, 98 male patients (mean age 68 years) with a history of intermittent claudication and an ankle/brachial index less than 0.9, and 94 controls matched for age but without PAD or ischaemic heart disease performed 24-h recordings of ambulatory BP. A total of 59 patients had a history of hypertension and 69 were on treatment with BP-lowering drugs as compared to 17 and 23 of the control subjects, respectively. Office as well as 24-h systolic BP (SBP) were higher in patients as compared to controls (151 +/- 22 vs 140 +/- 20 mmHg, P < 0.001 and 142 +/- 14 vs 133 +/- 15 mmHg, P < 0.001, respectively), but did not differ with regard to diastolic BP. In an analysis of covariance with the continuous factors age, office SBP and the categorical factor antihypertensive treatment, 24-h SBP was higher in PAD patients compared to controls (P < 0.05). The difference between office and night SBP was lower in PAD patients with antihypertensive treatment compared to controls (P = 0.01). In conclusion, Male patients with PAD had higher systolic but not diastolic BP than age-matched control subjects. In PAD patients, 24-h SBP was higher than expected from OBP compared to controls. Night SBP was higher only in patients with antihypertensive treatment. In PAD patients, especially when on antihypertensive treatment, the severity of hypertension may be underestimated when based on OBP only.     

Reproducibility of intra-arterial ambulatory blood pressure: effects of physical activity and posture

OBJECTIVE: To examine the effects of physical activity, body posture and sleep quality on the reproducibility of continuous ambulatory blood pressure monitoring. METHODS: Measurements were performed in 35 subjects (18 hypertensive, 11 male), mean +/- standard deviation age 49 +/- 13 years. Blood pressure (BP) was measured in the brachial artery, and beat-to-beat values of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure and heart rate (HR) were computed. Physical activity and posture were continuously measured with five accelerometers. Subjective quality of sleep was assessed with a questionnaire. Reproducibility was expressed as an intraclass correlation coefficient and as the standard deviation of the within-subject differences. RESULTS: Posture and activity significantly influenced BP and HR. From lying to sitting, the SBP, DBP and HR increased 6 mmHg, 8 mmHg and 8 beats/min, respectively. From sitting to standing these respective increases were 4 mmHg, 2 mmHg and 13 beats/min. A further rise in activity (from standing to moving generally or walking) increased the SBP by 7 mmHg and the HR by 7 beats/min, and decreased the DBP by 8 mmHg. For daytime SBP, DBP and HR, the intraclass correlation coefficient (standard deviation of the within-subject differences) values were 0.93 (7.2 mmHg), 0.94 (3.8 mmHg) and 0.90 (4.1 beats/min). For night-time these respective values were 0.98 (4.4 mmHg), 0.97 (2.5 mmHg) and 0.96 (2.2 beats/min). Correction for physical activity level and posture hardly improved the reproducibility of daytime BP and HR. Reproducibility of night-time BP and HR was not improved by correction for physical activity, supine position or self-reported sleep quality. CONCLUSIONS: Within-subject differences between ambulatory BP recordings cannot be explained by differences in physical activity and body posture.     

Interarm differences in seated systolic and diastolic blood pressure: the Hypertension Genetic Epidemiology Network study

OBJECTIVE: To examine whether blood pressure (BP) differs between arms in hypertensive siblings and randomly selected volunteers, and whether this difference is explained by cardiovascular risk factors. METHODS: The Hypertension Genetic Epidemiology Network recruited 2395 hypertensive siblings and 854 volunteers. BP was measured six times (three measurements per arm) in seated participants using a Dinamap monitor. The average of three measurements was calculated per arm and the difference taken between arms (i.e. interarm BP differences). RESULTS: The mean age of the subjects was 56 years, and about one-half of the sample was male. More than one-half of the sample was African-American. The mean diastolic BP was equal in the two arms in the random sample (68.8 versus 68.7 mmHg) and in hypertensive siblings (73.4 versus 73.1 mmHg), as was systolic BP (random, 119.6 versus 119.3 mmHg; hypertensives, 130.8 versus 130.7 mmHg). The mean interarm diastolic and systolic BP differences were 2.96 +/- 2.51 and 4.61 +/- 4.10 mmHg, respectively, in the random sample and were 3.09 +/- 2.73 and 5.35 +/- 4.98 mmHg, respectively, in hypertensive siblings. Few (random, 1.6%; hypertensives, 2.8%) had interarm diastolic BP differences > 10 mmHg, but 9.2% of the random sample and 14.2% of hypertensive siblings had systolic BP differences > 10 mmHg. Obesity, higher heart rate, and higher systolic BP were associated with larger interarm BP differences. These results have implications for blood pressure measurement in research settings and in screening programs.     

Hypotension associated with prone body position: a possible overlooked postural hypotension.

Conditions related to the dysregulation of blood pressure (BP), such as orthostatic hypotension, have been shown to be significantly associated with cardiovascular disease. Recently, the prone body position has been recognized as a possible postural factor leading to BP dysregulation. We conducted a cross-sectional study to investigate the BP response to a change in body position from supine to prone. The study subjects consisted of 271 middle-aged healthy males, randomly selected from the employees of a large manufacturing enterprise in Ehime Prefecture, Japan. Brachial BP and heart rate were measured in a sitting, supine and prone position, in that order, and each difference was defined as a postural change. The postural changes in aortic hemodynamics were also assessed using a SphygmoCor system. The basal BP measured in the sitting position was significantly decreased in the supine position (132+/-18 to 130+/-17 mmHg, p<0.001). A further reduction was observed after the postural change from supine to prone (130+/-17 to 125+/-16 mmHg, p<0.001). The heart rate was increased with the supine-to-prone postural change (4.1+/-5.8 beats/min, p<0.001), while it showed a significant decrease with the sitting-to-supine postural change (-7.6+/-5.6 beats/ min, p<0.05). The impact of BP reduction was more prominent in the aortic artery (-3.3+/-6.7%) than the brachial artery (-3.0+/-6.3%, p=0.020). Multiple regression analysis showed that basal systolic BP was a solely significant determinant of the prone-hypotension (beta=-0.309, p<0.001). In conclusion, these results indicate that lying in a prone posture could lead to unregulated postural hypotension, which has the possibility of being a novel predictor of cardiovascular frailty.     

Treatment of orthostatic hypotension with sleeping in the head-up tilt position, alone and in combination with fludrocortisone.

We studied the effect of sleeping in the head-up tilt (HUT) position, alone and in combination with fludrocortisone, on orthostatic tolerance and blood pressure (BP) in six patients with hypoadrenergic orthostatic hypotension. A high salt diet of 150-200 mmol Na+ d-1 was also administered. Combined treatment reduced orthostatic dizziness in all patients (P less than 0.001), and increased the maximal standing period to at least 10 min. HUT alone (n = 4) reduced the BP decrease after 1 min of standing from -64/-42/-25 +/- 29/21/17 mmHg to -53/-37/-23 +/- 31/24/20 mmHg (P less than 0.01 for systolic BP). Addition of fludrocortisone to HUT (HUT/fludro) (n = 5) further reduced the BP decrease after 1 min of standing from -63/-40/-24 +/- 20/12/11 mmHg to -21/-19/-8 +/- 12/10/5 mmHg (P less than 0.05 for systolic, mean and diastolic BP, respectively). BP at maximal standing time increased from 58/47/42 +/- 9/8/7 mmHg initially to 95/69/57 +/- 27/22/20 mmHg during combined treatment (P less than 0.05 for systolic and mean BP), and remained unchanged during the 14-month (range 8-70 month) follow-up period. Nocturnal sodium excretion decreased from 8.0 +/- 2.3 mmol h-1 to 5.9 +/- 1.9 mmol h-1 with combined treatment; body weight increased by 1.6 kg on average (range 0.5-2.4 kg) (P less than 0.01). We conclude that the combination of HUT and fludrocortisone effectively minimizes orthostatic symptoms and increases orthostatic BP in patients with hypo-adrenergic orthostatic hypotension.     

Systolic blood pressures are not comparable when home blood pressure is measured with a wrist or an arm validated monitor

OBJECTIVES: To compare home blood pressure values obtained with two validated OMRON (wrist or arm) monitors used sequentially in the same subject. METHODS: In 265 hypertensive subjects referred to hypertension specialists, a self measurement of blood pressure was performed sequentially with an OMRON M4-I (arm cuff, A/A, BHS validation) or OMRON RX-I (wrist cuff, B/B, BHS validation). Each patient recorded home blood pressure during two periods of 4 days with 3 measures in the morning and 3 in the evening. Order for use of each monitor was randomised. With wrist devices, subjects were advised to keep the arm at heart level during measurements. BP values were reported on a standardized document. Patients were asked by a questionnaire about the tolerance and feasibility of the 2 methods. RESULTS: In this population, aged 59 +/- 14 years, with 60% of men and a mean blood pressure of 152 +/- 21 / 86 +/- 14 mmHg, the home blood pressure values were 143 +/- 20/81 +/- 11 mmHg with the arm monitor and 135 +/- 10 / 80 +/- 11 mmHg with the wrist monitor. Mean SBP adjusted on age, initial blood pressure level and period order was significantly lower when home blood pressure monitoring has been recorded with a wrist monitor as compared to an arm monitor (p < 0.001). Self measurement of blood pressure was felt as easy in 92% with the arm monitor and in 96% with the wrist monitor (p < 0.05). Self measurement of blood pressure was felt as constraining in 14% with the arm monitor and in 7% with the wrist monitor (p < 0.01). The feasibility between the two devices was good with none of the value missing in 86% with the arm monitor and in 85% with the wrist monitor. The missing values were in 56% the fourth day. CONCLUSION: Despite the use of two validated monitors, mean SBP is significantly lower when home blood pressure monitoring is recorded with a wrist monitor as compared to an arm monitor. Uncertainty in the arm position with the use of wrist device could explain these results. When advising home blood pressure monitoring, care should be taken to recommend only the use of validated devices and to prefer the use of arm devices in order to avoid the uncertainty of an inadequate utilisation.     

Assessment of body position to quantify its effect on nocturnal blood pressure under ambulatory conditions

BACKGROUND: Nocturnal blood pressure readings may be influenced by body position because of variation in the vertical distance between heart and cuff level. OBJECTIVES: To quantify the effect of body position on nocturnal blood pressure and to assess whether this effect influences the reproducibility of nocturnal blood pressure. PATIENTS AND METHODS: In 16 individuals (three normotensive and 13 hypertensive) 24 h ambulatory measurement of blood pressure and body position was performed twice, separated by an interval of 2-6 weeks. Body position was measured with five acceleration sensors, which were mounted on the trunk and legs. RESULTS: During the first night, 43 +/- 31% of blood pressure values were measured while participants were in the supine position, 29 +/- 28% when they were lying on their side with the cuffed arm down and 28 +/- 29% when they were lying on their side with the cuffed arm up. During the second night these percentages were 40 +/- 29%, 32 +/- 29% and 28 +/- 25% respectively. Blood pressure readings obtained while individuals were lying with the cuffed arm up were about 10 mmHg lower than those obtained with the individual in either the supine position or lying with the cuffed arm down. After correction for the underestimation attributable to 'cuff-up' readings, nocturnal blood pressure increased by 3 mmHg and the number of non-dippers increased from two to four. Correction did not affect the reproducibility of nocturnal blood pressure measurements (standard deviation of the differences 8.3 mmHg for systolic and 6.0 mmHg for diastolic blood pressure after correction). Dipping status was reproduced in 88% of individuals before correction, and in 87% after correction. CONCLUSIONS: Under ambulatory conditions, a highly variable but sometimes substantial number of blood pressure readings are taken with the cuffed arm above heart level. These readings result in underestimation of nocturnal blood pressure and hence influence dipper-non-dipper classification. However, body position does not seem to have an important influence on the reproducibility of nocturnal blood pressure or dipping status.     

Ambulatory blood pressure in the young adult with hypertension history during childhood]

The tendency of subjects to maintain their relative position within the distribution of blood pressure (BP) has been defined as "tracking". Regarding this phenomenon, the purpose of the study was to evaluate the interest of ambulatory BP monitoring (ABPM) in the assessment of arterial hypertension in young adults (YA) with childhood hypertension history (CHH). 52 subjects, 20.1 +/- 2.4 years old, 26 men, 26 women issued from a cohort of 150 children with high BP levels (greater than 97.5 th percentile) during their infancy (school check-up), were included in the study. An ABPM was performed with space-labs system 90202 from 8 a.m. to 6 p.m., measurements every 15 minutes (37.6 +/- 7.4 readings). Left ventricular mass index (LVMI) was determined with echocardiography, (Penn convention). Office BP, measured with mercury apparatus in lying and standing position, was respectively, 131.0 +/- 14.6/81.9 +/- 9.7 and 130.1 +/- 14/86.6 +/- 9.9. According to JNC 1988, this casual BP identified 40 normotensives (NT), 9 borderlines (BL) and 5 hypertensives (HT); 10 of them had a "high normal" diastolic BP (85-90 mmHg) ABP recordings of the study group were compared to day-time reference values of NT. Three subgroups are individualized: G1 NT, G2 HT, G3 BL. [table; see text] *p: less than 0.001; p: less than 0.01. Wall thickness (WTh) and LVMI were significantly higher in hypertensives (G2 + G3) than in normotensives (G1): [table; see text] There was a significant correlation between LVMI and mean systolic ABP (p less than 0.01: r = 0.44), but not with office SBP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidemiological Perspective of Body Position and Arm Level in Blood Pressure Measurement

According to official recommendations, indirect blood pressure (BP) measurement should be performed in the brachial artery at heart level in the seated position. At lower levels the hydrostatic pressure of the column of blood in between the heart and the point of measurement is added. The clinical relevance of deviations from the recommendations was investigated in a population-based sample of 401 healthy men and women of ages 15-84 years. In the seated position, the systolic BP measured with the upper arm parallel to the sternum was higher than that with the forearm elevated at heart level. The difference was 9.4 (SD 6.6) mm in men and 8.2 (6.9) mm in women. The corresponding differences in diastolic BP were 13.6 (4.4) mm in men and 12.4 (4.5) mm in women. At heart level, the supine systolic BP was 7.9 (7.5) mm higher than the seated in men, and 8.2 (8.0) mm higher in women, while the diastolic BP was the same up to the age of 40. It is concluded that deviations from the recommended body position and arm level are clinically relevant. The pattern of discrepancy, falsely high BPs below the heart level and a higher pulse pressure in the supine position, is uniform in both sexes at all adult ages.     

Comparison of the Omron HEM-637 wrist monitor to the auscultation method with the wrist position sensor on or disabled

BACKGROUND: To determine whether the Omron HEM637 wrist model with the wrist positioning sensor turned on (Son) is more accurate relative to upper arm auscultation by trained professionals than when the sensor was manually turned off (Soff). METHODS: Forty-four subjects, at least 30 years old, had repeated, sequential dual-observer upper arm auscultatory measurements (5 to 6 each) and oscillometric Omron HEM637 wrist measurements (4 each). Nineteen subjects were assigned to the wrist sensor On group and 25 were assigned to the wrist sensor Off group. A total of 425 auscultatory and 164 wrist measurements were analyzed. RESULTS: The Omron HEM-637 measured the blood pressure (BP) with equal accuracy to the observers using the auscultatory technique (difference -1.37 +/- 8.51/3.47 +/- 8.07 mm Hg, P =.71/.14). The wrist sensor did improve the accuracy of the measurements compared to the subjects that had the sensor deactivated. The sensor On group (Son) measured the systolic BP (0.82 +/- 9.83 mm Hg) and diastolic BP (-0.72 +/- 9.07 mm Hg) statistically the same as by auscultation (P =.86 for systolic BP and P =.83 for diastolic BP). The sensor Off (Soff) group measured the SBP (-3.03 +/- 7.12 mm Hg) and diastolic BP (-5.56 +/- 6.68 mm Hg) statistically different than auscultation (P =.46 for systolic BP and P =.02 for diastolic BP). The higher (negative) measurement for both the systolic BP and diastolic BP suggests that the average position of the wrist was 1.75 inches (4.4 cm) below the heart level in this group with the sensor off. CONCLUSIONS: This study demonstrated that the Omron HEM-637 monitor with a wrist sensor more accurately measured BP compared to the same model with the sensor turned off.