Changes in home versus clinic blood pressure with antihypertensive treatments: a meta-analysis

Home blood pressure (HBP) monitoring is recommended for assessing the effects of antihypertensive treatment, but it is not clear how the treatment-induced changes in HBP compare with the changes in clinic blood pressure (CBP). We searched PubMed using the terms "home or self-measured blood pressure," and selected articles in which the changes in CBP and HBP (using the upper arm oscillometric method) induced by antihypertensive drugs were presented. We performed a systematic review of 30 articles published before March 2008 that included a total of 6794 subjects. As there was significant heterogeneity in most of the outcomes, a random effects model was used for the meta-analyses. The mean changes (+/-SE) in CBP and HBP (systolic/diastolic) were -15.2+/-0.03/-10.3+/-0.03 mm Hg and -12.2+/-0.04/-8.0+/-0.04 mm Hg respectively, although there were wide varieties of differences in the reduction between HBP and CBP. The reductions in CBP were correlated with those of HBP (systolic BP; r=0.66, B=0.48, diastolic BP; r=0.71, B=0.52, P<0.001). In 7 studies that also included 24-hour BP monitoring, the reduction of HBP was greater than that of 24-hour BP in systolic (HBP; -12.6+/-0.06 mm Hg, 24-hour BP; -11.9+/-0.04 mm Hg, P<0.001). In 5 studies that included daytime and nighttime systolic BP separately, HBP decreased 15% more than daytime ambulatory BP and 30% more than nighttime ambulatory BP. In conclusion, HBP falls approximately 20% less than CBP with antihypertensive treatments. Daytime systolic BP falls 15% less and nighttime systolic BP falls 30% less than home systolic BP.     

The bedtime administration of doxazosin controls morning hypertension and albuminuria in patients with type-2 diabetes: evaluation using home-based blood pressure measurements

The control of high blood pressure (BP) after awakening in the morning (morning hypertension) as determined by home BP (HBP), as well as BP control throughout the day, may prevent diabetic vascular complications. We examined the effect of an alpha-adrenergic blocker (doxazosin) on BP measurements taken by HBP after awakening and during clinic visits (CBP) in 50 patients with type-2 diabetes and morning hypertension. We evaluated the urinary albumin excretion rate as an indicator of nephropathy. Doxazosin was taken orally once at bedtime for 1 to 3 months. The mean (+/- SD) dose was 2.9 +/- 2.1 mg/day (1 to 8 mg/day). The BP was measured monthly at the clinic during the day and at home after awakening in the morning. In this short-term trial (2.8 +/- 0.4 months), the systolic HBP decreased significantly from 164 +/- 17 mmHg before treatment to 146 +/- 19 mmHg after treatment, and the diastolic HBP decreased significantly from 85 +/- 14 mmHg before treatment to 80 +/- 9 mmHg after treatment. The systolic, but not the diastolic CBP, decreased significantly after treatment. There was no significant difference in the systolic or diastolic values between the HBP and the CBP after treatment. The percentage change in the systolic HBP after treatment was three times greater than for the systolic CBP. The median (interquartile) urinary albumin excretion rate decreased significantly (P < 0.001) from 62 (25-203) mg/g creatinine before treatment to 19 (9-76) mg/g creatinine after treatment. On multiple regression analysis, the decrease in the systolic HBP with treatment positively correlated with the reduction in urinary excretion of albumin. The control of morning hypertension reduced the albuminuria found in both untreated and treated hypertensive patients with type-2 diabetes. Bedtime administration of doxazosin appears to be safe and effective in reducing morning hypertension as measured by HBP. This finding also demonstrates that HBP taken in the morning has a stronger predictive power for the albuminuria level than does CBP.     

Masked Hypertension Assessed by Ambulatory Blood Pressure Versus Home Blood Pressure Monitoring: Is It the Same Phenomenon?

BACKGROUND: Masked hypertension is defined as normal clinic blood pressure (CBP) and elevated out-of-clinic blood pressure assessed using either self-monitoring of blood pressure (BP) by the patients at home (HBP) or ambulatory BP (ABP) monitoring. This study investigated the level of agreement between ABP and HBP in the diagnosis of masked hypertension. METHODS: Participants referred to an outpatient hypertension clinic had measurements of CBP (two visits), HBP (4 days), and ABP (24 h). The diagnosis of masked hypertension based on HBP (CBP <140/90 mm Hg and HBP > or =135/85) versus ABP (CBP <140/90 and awake ABP > or =135/85) was compared. RESULTS: A total of 438 subjects were included (mean age +/- SD, 51.5 +/- 11.6 years; 59% men and 41% women, 34% treated and 66% untreated). Similar proportions of subjects with masked hypertension were diagnosed by ABP (14.2%) and HBP (11.9%). In both treated and untreated subjects, the masked hypertension phenomenon was as common as the white coat phenomenon. Among 132 subjects with normal CBP, there was disagreement in the diagnosis of masked hypertension between the HBP and the ABP method in 23% of subjects for systolic and 30% for diastolic BP (kappa 0.56). When a 5-mm Hg gray zone for uncertain diagnosis was applied to the diagnostic threshold, the disagreement was reduced to 9% and 6% respectively. CONCLUSIONS: Similar proportions of subjects with masked hypertension are detected by ABP and HBP monitoring. Although disagreement in the diagnosis between the two methods is not uncommon, in the majority of these cases the deviation of the diagnostic BP above the threshold in not clinically important. Both ABP and HBP monitoring appear to be appropriate methods for the detection of masked hypertension.     

Circadian rhythm of blood pressure in patients with obstructive sleep apnea.

AIMS: The aims of this study were to examine the circadian variation in blood pressure (BP) in obstructive sleep apnea (OSA) and to compare this between normotensive and hypertensive subjects. METHODS: We measured 24-hour ambulatory BP (ABP) in 72 men (mean age 51 +/- 8 years), with OSA diagnosed on overnight sleep study. Measurements of BP were made at 15 min intervals for 24 h using either an Oxford Medilog ABP or Spacelabs 90207 recorder. All recordings were performed after > or = 3 week washout of anti-hypertensive drugs. The day-time monitoring period was defined as 07:00 hrs to 22:00 and night-time 22:00 to 07:00. The ratio of night:day systolic and diastolic BP was calculated. RESULTS: The patients were obese (mean body mass index 33 +/- 5 kg/m2) with a central pattern of obesity (waist:hip ratio 0.99 +/- 0.14, normal < 0.94). The mean 24-h ABP (systolic/diastolic) was 138 +/- 18/88 +/- 12 mmHg. The mean daytime ABP was 143 +/- 18/93 +/- 12 and night-time ABP 128 +/- 20/80 +/- 12 Hg. The night:day BP ratio was 0.90 +/- 0.07 (systolic) and 0.87 +/- 0.09 (diastolic) indicating that average BP was lower during the night. This pattern was similar in normotensive and hypertensive subjects. In contrast there was a significant relationship between increasing BMI and night:day blood pressure ratio (r = 0.56, p < 0.001) independent of the effects of OSA. CONCLUSION: In contrast to previous studies, men with OSA have a normal diurnal pattern of blood pressure levels. These findings suggest that any influence of OSA on BP is manifested throughout the 24-h period.     

White coat effect in treated versus untreated hypertensive individuals: a case-control study using ambulatory and home blood pressure monitoring

BACKGROUND: Some studies have shown a significant white coat effect (WCE) (i.e., difference between clinic blood pressure [CBP] and awake ambulatory blood pressure [ABP]) to be present not only in untreated but also in treated hypertensive individuals. This study aims to assess 1) the prevalence and the magnitude of the WCE in treated versus untreated hypertensive persons, and 2) the usefulness of home blood pressure (HBP) versus ABP in the detection of this phenomenon. METHODS: A case-control study was conducted in 138 treated hypertensive patients and same number of sex- and age-matched untreated hypertensive subjects who had measurements of CBP (at least three visits), HBP, and ABP. Subjects with a WCE of >20/10 mm Hg (systolic/diastolic) were classified as clinic reactors. RESULTS: There was a trend for a larger WCE assessed by ABP monitoring in the untreated group (mean difference in systolic WCE, 1.8 +/- 22.2 mm Hg, 95% CI -2.0 to 5.5; diastolic 1.8 +/- 11.9 mm Hg, 95% CI -0.2 to 3.8) and for more untreated clinic reactors (27% untreated v 20% treated, odds ratio 1.5, 95% CI 0.9 to 2.7). The sensitivity, specificity, and positive and negative predictive values of HBP to detect clinic reactors correctly were 56%/62% (treated/untreated), 87%/84%, 52%/59%, and 89%/86%, respectively, with moderate agreement between HBP and ABP (kappa 0.42/0.46). CONCLUSIONS: In treated hypertensive patients, WCE seems to be reduced compared with that in untreated hypertensive persons but is not eliminated. In both untreated and treated hypertensive individuals HBP monitoring appears to be useful in the detection of the WCE, but it may not be appropriate as an alternative to the ABP method.     

Self-measured versus ambulatory blood pressure in the diagnosis of hypertension

OBJECTIVE: We examined to what extent self-measurement of blood pressure at home (HBP) can be an alternative to ambulatory monitoring (ABP) to diagnose white-coat hypertension. METHODS: In 247 untreated patients, we compared the white-coat effects obtained by HBP and ABP. The thresholds to diagnose hypertension were > or = 140/> or = 90 mmHg for conventional blood pressure (CBP) and > or = 135/> or = 85 mmHg for daytime ABP and HBP. RESULTS: Mean systolic/diastolic CBP, HBP and ABP were 155.4/100.0, 143.1/91.5 and 148.1/95.0 mmHg, respectively. The white-coat effect was 5.0/3.5 mmHg larger on HBP compared with ABP (12.3/8.6 versus 7.2/5.0 mmHg; P < 0.001). The correlation coefficients between the white-coat effects based on HBP and ABP were 0.74 systolic and 0.60 diastolic (P < 0.001). With ABP as a reference, the specificity of HBP to detect white-coat hypertension was 88.6%, and the sensitivity was 68.4%. CONCLUSION: Our findings are in line with the recommendations of the ASH Ad Hoc Panel that recommends HBP for screening while ABP has a better prognostic accuracy.     

The ambulatory blood pressure in normotensive and hypertensive subjects: results from an international database

Objective: To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement.Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (systolic CBP ≤ 140 mmHg and diastolic CBP ≤ 90 mmHg) and 1773 were hypertensive (systolic CBP ≥ 160 mmHg and/or diastolic CBP ≥ 90 mmHg). Of the latter, 1324 had systolic and 1310 had diastolic hypertension.Results: Ninety-five percent of the normotensive subjects had a 24-h ABP below (systolic and diastolic, respectively) 133 and 82 mmHg. Of the patients with systolic hypertension, 24% had a 24-h systolic ABP of < 133 mmHg. Similarly, 30% of those with diastolic hypertension had a 24-h diastolic ABP of < 82 mmHg. The probability that hypertensive patients had a 24-h ABP below these thresholds was higher in women than in men, increased with age and was 2- to 4-fold greater if the CBP of the patient had been measured at only one visit and if fewer than 3 CBP measurements had been averaged to establish the diagnosis of hypertension. By contrast, for each 10-mmHg increment in systolic CBP, this probability decreased by 54% for the 24-h systolic ABP and by 25% for the 24-h diastolic ABP, and for each 5 mmHg increment in diastolic CBP it increased by 6 and 9%, respectively.Conclusion: The ABP distributions of the normotensive subjects included in the present international database were not materially different from those in previous reports in the literature. One-fifth to more than one-third of the hypertensive patients had an ABP which was below the 95th centile of the ABP in normotensive subjects, but this proportion decreased if the hypertensive patients had shown a higher CBP upon repeated measurement. The prognostic implications of elevated CBP in the presence of normal ABP remain to be determined.     

Significance of white-coat hypertension in older persons with isolated systolic hypertension: a meta-analysis using the International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes population

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding persons with diastolic hypertension by CBP (≥90 mm Hg) or by daytime ABP (≥85 mm Hg), a history of cardiovascular disease, and persons <18 years of age, the present analysis totaled 7295 persons, of whom 1593 had isolated systolic hypertension. During a median follow-up of 10.6 years, there was a total of 655 fatal and nonfatal cardiovascular events. The analyses were stratified by treatment status. In untreated subjects, those with white-coat hypertension (CBP ≥140/<90 mm Hg and ABP <135/<85 mm Hg) and subjects with normal BP (CBP <140/<90 mm Hg and ABP <135/<85 mm Hg) were at similar risk (adjusted hazard rate: 1.17 [95% CI: 0.87-1.57]; P=0.29). Furthermore, in treated subjects with isolated systolic hypertension, the cardiovascular risk was similar in elevated conventional and normal daytime systolic BP as compared with those with normal conventional and normal daytime BPs (adjusted hazard rate: 1.10 [95% CI: 0.79-1.53]; P=0.57). However, both treated isolated systolic hypertension subjects with white-coat hypertension (adjusted hazard rate: 2.00; [95% CI: 1.43-2.79]; P<0.0001) and treated subjects with normal BP (adjusted hazard rate: 1.98 [95% CI: 1.49-2.62]; P<0.0001) were at higher risk as compared with untreated normotensive subjects. In conclusion, subjects with sustained hypertension who have their ABP normalized on antihypertensive therapy but with residual white-coat effect by CBP measurement have an entity that we have termed, "treated normalized hypertension." Therefore, one should be cautious in applying the term "white-coat hypertension" to persons receiving antihypertensive treatment.     

Ambulatory blood pressure is still elevated in treated hypertensive diabetic subjects compared with untreated diabetic subjects with the same office blood pressure.

Ambulatory blood pressure, ABP, was determined every 15 min for 24 h (Spacelabs 5200 system) in 16 hypertensive diabetic subjects treated for high blood pressure. Office blood pressure (OBP) in these subjects (systolic BP greater than 160 mmHg and diastolic BP greater than 95 mmHg before treatment) had been reduced by treatment to the borderline range (systolic less than or equal to 160 mmHg and/or diastolic less than or equal to 95 mmHg). Sixty-five diabetic subjects with normal or borderline OBP were included as controls. The two groups had the same age (58 +/- 10 yrs in both groups), duration of diabetes (15 +/- 9 yrs), 24 hr microalbumin, and included the same percentage of subjects with moderate neuropathy (36% and 29%, NS). The two groups had the same OBP (138 +/- 16 mmHg and 140 +/- 16 mmHg systolic, NS, 84 +/- 9 mmHg and 84 +/- 13 mmHg diastolic, NS). In contrast, ambulatory BP was significantly higher in the treated group, when compared with the controls (123 +/- 13 mmHg and 133 +/- 23 mmHg systolic, P less than 0.025, 77 +/- 7 mmHg and 84 +/- 16 mmHg diastolic, P less than 0.015). The difference was significant both in daytime and in nighttime, and was more significant in nighttime (11 mmHg systolic, P less than 0.02, 9 mmHg diastolic, P less than 0.004) than in daytime (9 mmHg systolic, P less than 0.05 and 5 mmHg diastolic, P less than 0.05). Ambulatory heart rate was also significantly higher in the treated group, but only in daytime (7 b/min difference, P less than 0.02). The study demonstrated the need to survey and investigate ABP in treated hypertensive diabetic subjects.     

Accuracy of telemedical home blood pressure measurement in the diagnosis of hypertension

This study was conducted to compare the accuracy of clinic blood pressure (CBP) and telemedical home blood pressure (HBP) measurement in the diagnosis of hypertension in primary care. The study subjects were 411 patients with average CBP > or =140 mmHg systolic or > or =90 mmHg diastolic, who performed telemedical HBP measurement (5 days, four times daily) and ambulatory blood pressure (ABP) monitoring in random order. Main outcome measure was the agreement of CBP and HBP with daytime ABP. CBP was much higher than daytime ABP and average HBP (P<0.001) with no difference between the latter two. The correlation between CBP and ABP was weak (systolic: r=0.499, diastolic: r=0.543), whereas strong correlations existed between HBP and ABP (systolic: r=0.847, diastolic: r=0.812). A progressive improvement in the strength of the linear regression between average HBP of single days and ABP was obtained from day 1 to day 4, with no further benefit obtained on the fifth day. The HBP readings taken at noon and in the afternoon showed significantly stronger correlations with ABP than the blood pressures measured in the morning and in the evening. In conclusion, the accuracy of telemedical HBP measurement was substantially better than that of CBP in the diagnosis of hypertension in primary care. HBP most accurately reflected ABP on the fourth day of monitoring, and the readings at noon and in the afternoon seemed to be most accurate.     

Effects of age on hypertensive status in patients with chronic kidney disease

OBJECTIVE: To evaluate effect of age on hypertensive status in chronic kidney disease (CKD). METHODS: We studied 459 prevalent CKD patients (stages 2-5, no dialysis), grouped by age (< 55, 55-64, 65-74, >or= 75 years), undergoing clinical blood pressure (CBP) and ambulatory blood pressure (ABP) measurement. RESULTS: Prevalence of diabetes, left ventricular hypertrophy and previous cardiovascular disease progressively increased with aging; glomerular filtration rate (GFR) and hemoglobin decreased. Achievement of CBP target decreased from 16% in patients < 55 years to 6% in those >or= 75 years (P = 0.023). ABP 24-h systolic rose while diastolic decreased, with a consequent pulse pressure increase from 45 +/- 8 to 65 +/- 14 mmHg (P < 0.0001). Age, proteinuria, diabetes, cardiovascular disease and anemia but not GFR predicted higher 24-h pulse pressure. CBP overestimated systolic/diastolic daytime ABP by 14 +/- 18/7 +/- 11 mmHg on average, a greater difference in older than younger groups (P < 0.005). Conversely, CBP night-time ABP difference did not vary among groups (24 +/- 20/16 +/- 11 mmHg). These age-dependent differences determined a rising prevalence of white-coat hypertension (from 19 to 40%, P = 0.001) and night/day ratio of at least 0.9 (from 43 to 66%, P = 0.0004). Age, diabetes, left ventricular hypertrophy and anemia but not GFR predicted nondipping status. Among the oldest patients, 13% had diastolic CBP below 70 mmHg, with 48% below the corresponding values of daytime (< 69 mmHg) or night-time ABP (< 60 mmHg). CONCLUSION: In CKD, prevalence of white-coat hypertension, nondipping status and potentially dangerous low diastolic ABP increases with aging. This suggests wider use of ABP monitoring in older patients and need for trials addressing identification of an age-specific blood pressure target.     

Assessment of the diurnal blood pressure profile and detection of non-dippers based on home or ambulatory monitoring

BackgroundA unique advantage of ambulatory blood pressure (ABP) monitoring is the assessment of nocturnal blood pressure (BP) and the detection of non-dippers. This study assessed nocturnal BP and non-dippers using a novel home BP (HBP) monitor.MethodsEighty-one hypertensives performed within 2 weeks ABP (24-h, Microlife WatchBP O3) and HBP monitoring (Microlife WatchBPN) during daytime (6 days, duplicate morning and evening measurements) and nighttime (automated asleep measurements, 3 nights, 3 readings/night). Patients' preference in using ABP or HBP was assessed by a questionnaire.ResultsStrong associations were found between ABP and HBP (intraclass correlation coefficients for awake systolic/diastolic 0.75/0.81; asleep 0.87/0.85). No statistically significant difference was found between HBP and ABP (mean difference ± SD awake systolic/diastolic 1.5 ± 10.1/-1.1 ± 6.0 mm Hg, P = 0.20/0.09; asleep -0.4 ± 7.8/-1.0 ± 5.3, P = 0.63/0.09). There was substantial agreement (74%, kappa 0.2) between ABP and HBP in the detection of non-dippers, which was similar to the previously reported test-retest reproducibility of repeated ABP monitoring in the diagnosis of non-dippers. Moderate to severe disturbance from ABP monitoring was reported by 18% of the participants and severe restriction of their daily activities by 9, vs. 3 and 1.5%, respectively for HBP (P < 0.001/ <0.01, for comparisons respectively). Nighttime BP monitoring and cuff discomfort were the main complaints for ABP (46 and 32%, respectively) and HBP (34 and 28%), whereas 89% reported more nighttime sleep disturbance by ABP than HBP (P < 0.001).ConclusionsHBP monitoring appears to be a reliable and well accepted by users alternative to ABP for the assessment of nocturnal BP and the detection of non-dippers.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.82.     

Reproducibility of home and ambulatory blood pressure in children and adolescents

OBJECTIVE: To evaluate the reproducibility of blood pressure measured at home (HBP) in comparison with ambulatory (ABP) and clinic blood pressure (CBP) in children and adolescents. PARTICIPANTS AND METHODS: Individuals aged 8-17 years who had been referred for elevated CBP were included. CBP was measured at two visits, HBP on 5 days and ABP for 24 h. A second session including all the above measurements was performed after 8 weeks. The reproducibility of CBP (second visit of each session), HBP (average of days 2-5 of each session) and ABP (average 24-h, awake and asleep) was quantified using test-retest correlations coefficients (r) and the standard deviation of differences (SDD) between repeated measurements. RESULTS: Sixteen individuals were included [mean age 13.3+/-2.9 (SD)] years, range 8-17, nine boys]. According to Task Force CBP criteria, eight were classified as hypertensives, three as high normal and five as normotensives. The reproducibility of HBP (systolic/diastolic r, 0.74/0.82, SDD 7.0/4.3) was superior to that of CBP (r, 0.63/0.80, SDD 10.4/6.3). However, ABP appeared to provide the most reproducible values (r, 0.87/0.84, SDD 5.5/4.3 for 24-h ABP; r, 0.85/0.76, SDD 5.9/5.0 for awake; r, 0.76/0.79, SDD 7.0/5.0 for asleep ABP). Aspects of the diurnal ABP variation were poorly reproducible (r, 0.62/0.14, SDD 6.8/5.5 for awake-asleep ABP difference; r, 0.55/0.26, SDD 0.07/0.11 for awake : asleep ratio). CONCLUSION: These data suggest that in children and adolescents home blood pressure measurements are more reproducible than clinic measurements. However, 24-h ambulatory monitoring appears to provide the most reproducible blood pressure values.     

Tele-monitoring of home blood pressure in treated hypertensive patients

AIM: To compare the accuracy of clinic blood pressure (CBP) and telemedical home blood pressure (HBP) measurement in the assessment of antihypertensive effect. METHODS: 362 patients on antihypertensive medication performed HBP measurement (5 days, duplicate measurements, four times daily) and ambulatory blood pressure (ABP) monitoring in random order. Main outcome measure was the agreement of CBP and HBP with daytime ABP. RESULTS: CBP was much higher than ABP and average HBP (p < 0.001). There was a progressive decline in HBP over the course of the study, achieving the level of daytime ABP on the last 2 monitoring days. The correlation between CBP and ABP was weak (systolic: r = 0.343, diastolic r = 0.430), whereas strong correlations existed between HBP and ABP (systolic r = 0.804, diastolic r = 0.776). A progressive improvement in the strength of the correlation between average HBP of single days and ABP was obtained over the 5 monitoring days. The HBP readings taken in the afternoon showed a stronger correlation with ABP than the values measured in the morning, at noon and in the evening. Averaging more HBP readings taken on succeeding days resulted in a progressive improvement in the agreement with ABP with a further benefit when readings of day 1 were included. CONCLUSIONS: The accuracy of telemedical HBP measurement is substantially better than that of CBP. The results suggest, that HBP should be measured for 5 days, and afternoon measurements should be preferred in assessing control of hypertension.     

Home blood pressure monitoring in children: how many measurements are needed?

OBJECTIVE: To investigate the minimum schedule of blood pressure (BP) measurements necessary to provide a reliable assessment of home BP (HBP) in children and adolescents. METHODS: Subjects aged 6-18 years referred for elevated BP were assessed with HBP monitoring (6 workdays, duplicate morning and evening measurements) and 24-h ambulatory BP monitoring (ABP). Criteria for HBP reliability were its reproducibility (test-retest correlations and SD of differences (SDDs) between repeated measurements), its stability (average home BP of an increasing number of readings and its SD), and its relationship with ABP. RESULTS: Data from 100 subjects were analyzed (mean age 13 +/- 2.8 (SD) years, 61 boys). The reproducibility of 3-day HBP (r 0.88/0.79, SDDs 5.1/4.9, systolic/diastolic) was superior to that of a single (r 0.79/0.65, SDDs 7.6/7.1) or 2-day HBP (r 0.85/0.72, SDDs 6.1/5.4). By averaging up to 12 readings (3 days), there was a progressive decline in average HBP, with no further decline thereafter. The SD of average HBP was also progressively reduced, with little change after day 3. The association of HBP with ABP was improved by averaging more readings up to 12, with no further improvement when more readings were averaged. The exclusion of first-day measurements slightly increased the SD of average HBP and weakened the correlation with ABP, probably due to reduced number of readings. CONCLUSIONS: In children and adolescents, 3-day monitoring with duplicate morning and evening measurements appears to be the minimum schedule for the reliable assessment of HBP.     

Left ventricular hypertrophy in treated hypertensive patients with good blood pressure control outside the clinic,but poor clinic blood pressure control

OBJECTIVE: The aim of the study was to evaluate the prevalence of left ventricular hypertrophy (LVH) in treated patients with good blood pressure (BP) control during multiple home BP (HBP) measurements and during 24-h ambulatory BP monitoring (ABPM), but with unsatisfactory BP control in the clinic. These patients were compared with treated hypertensives whose BP was well controlled under the three circumstances. METHODS: Seventy-two treated consecutive patients (group I, age 56 +/- 10 years) with clinic BP values > or = 140/90 mmHg, and a difference between clinic and self-measured HBP > 10 mmHg for diastolic blood pressure (DBP) and/or > 20 mmHg for systolic blood pressure (SBP), underwent the following procedures: (1) clinic BP measurement; (2) routine diagnostic work-up; (3) HBP monitoring; (4) 24-h ABPM; (5) echocardiography. Thirty-five hypertensive patients with satisfactory BP control according to clinic (< 140/90 mmHg), HBP (< or = 131/82 mmHg) and ABP criteria (< or = 125/79 mmHg) were included as the control group (group II, age 55 +/- 9 years). RESULTS: In group I, 33 subjects out of the 72 (46%) with clinic BP > 140/90 mmHg had BP values controlled outside the clinic (23 according to HBP criteria and 22 according to ABP criteria). The prevalence of LVH (LV mass index > 134 g/m2 in men and > 110 g/m2 in women) was significantly higher in these patients (15.1 versus 2.8%, P < 0.01) than in group II (BP also controlled in the clinic), despite the fact that HBP and ABP were reduced to similar levels in the two groups. CONCLUSIONS Our data provide evidence that treated hypertensive patients with good BP control at home or during ambulatory monitoring, but incomplete BP control in the clinic, have more pronounced cardiac alterations than patients with both clinic and out of the clinic BP control. This finding offers a new piece of information about the diagnostic value of BP measurement in the clinic to assess BP control during antihypertensive treatment.     

White coat effect and white coat hypertension in community pharmacy practice

OBJECTIVE: The aim of the present study was to investigate whether a white coat effect (WCE) can be observed and quantified in community pharmacy practice. METHODS: In five community pharmacies of Basel, Switzerland, clients asking for blood pressure (BP) measurement were recruited to participate in a free of charge study. Blood pressure was measured in four different settings: pharmacy (using mercury sphygmomanometers), outpatient clinic (measurement by a nurse using mercury sphygmomanometers), self-measurement at home (using automated wrist devices) and daytime ambulatory BP (ABP) monitoring (using SpaceLabs 90207 monitors). WCE was defined as the difference between pharmacy or outpatient and daytime ABP. RESULTS: A total of 50 subjects completed all measurements (42% male, mean age 53.7 years+/-14.0). Blood pressure values of the different settings: (means in mmHg+/-SD, systolic; diastolic): pharmacy BP 129+/-19; 82+/-10, outpatient clinic BP 127+/-15; 82+/-10, home BP 119+/-15; 73+/-9, daytime ABP 124+/-10; 79+/-8. Pharmacy BP was significantly higher (P=0.03 systolic; P=0.02 diastolic) compared with daytime ABP and differences among subjects with antihypertensive medication (n=22) were even more significant (P<0.01). Individual differences were found between pharmacy BP and daytime ABP: +4.6+/-14.8; +2.9+/-8.3. Outpatient BP was significantly higher compared with daytime ABP in diastolic (P=0.04) but not in systolic values. Individual differences between outpatient BP and daytime ABP were +2.5+/-13.1; +2.8+/-9.2. 'Clinically important WCE' (>or=20 mmHg systolic or >or=10 mmHg diastolic) was observed in 24% of all subjects in the pharmacy and in 20% in the outpatient clinic. CONCLUSIONS: Our findings show that WCE and white coat hypertension exist in community pharmacy practice and are similar to the effects in an outpatient clinic.     

Can validated wrist devices with position sensors replace arm devices for self-home blood pressure monitoring? A randomized crossover trial using ambulatory monitoring as reference

BACKGROUND: Electronic devices that measure blood pressure (BP) at the arm level are regarded as more accurate than wrist devices and are preferred for home BP (HBP) monitoring. Recently, wrist devices with position sensors have been successfully validated using established protocols. This study assessed whether HBP values measured with validated wrist devices are sufficiently reliable to be used for making patient-related decisions in clinical practice. METHODS: This randomized crossover study compared HBP measurements taken using validated wrist devices (wrist-HBP, Omron R7 with position sensor) with those taken using arm devices (arm-HBP, Omron 705IT), and also with measurements of awake ambulatory BP (ABP, SpaceLabs), in 79 subjects (36 men and 43 women) with hypertension. The mean age of the study population was 56.7 +/- 11.8 years, and 33 of the subjects were not under treatment for hypertension. RESULTS: The average arm-HBP was higher than the average wrist-HBP (mean difference, systolic 5.2 +/- 9.1 mm Hg, P < 0.001, and diastolic 2.2 +/- 6.7, P < 0.01). Twenty-seven subjects (34%) had a > or =10 mm Hg difference between systolic wrist-HBP and arm-HBP and twelve subjects (15%) showed similar levels of disparity in diastolic HBP readings. Strong correlations were found between arm-HBP and wrist-HBP (r 0.74/0.74, systolic/diastolic, P < 0.0001). However, ABP was more strongly correlated with arm-HBP (r 0.73/0.76) than with wrist-HBP (0.55/0.69). The wrist-arm HBP difference was associated with systolic ABP (r 0.34) and pulse pressure (r 0.29), but not with diastolic ABP, sex, age, arm circumference, and wrist circumference. CONCLUSIONS: There might be important differences in HBP measured using validated wrist devices with position sensor vs. arm devices, and these could impact decisions relating to the patient in clinical practice.Measurements taken using arm devices are more closely related to ABP values than those recorded by wrist devices. More research is needed before recommending the widespread use of wrist monitors in clinical practice.American Journal of Hypertension doi:10.1038/ajh.2008.176American Journal of Hypertension (2008); 21, 7, 753-758. doi:10.1038/ajh.2008.176.     

Sodium and potassium in children with hypertension

On a baseline survey of 4936 school children, age ranged from 6 to 16 years, 199 children with the systolic blood pressure (SBP) value equal or greater than 95-th percentiles for age and sex were chosen as the hypertensive group (HBP), and the same number of children with the SBP lower than 50-th percentiles were matched as the normotensive group (NBP). For both groups the intra-RBC and plasma Na and K content, three sequential nights 8-hour urinary Na, K and creatinine excretion, and an oral saline-load test were performed. The results show that: (1) The intra-RBC K in the HBP was lower than in NBP, 259 +/- 57 vs 291 +/- 78 mumol/g-protein, P less than 0.01. That in those with positive hypertensive family history (FH+) was lower than in those of negatives (FH-). The intra-RBC K content was correlated inversely with diastolic BP, r = -0.43, P less than 0.001. No correlation between intra-RBC Na and BP was found; (2) Plasma Na concentration in HBP was much lower than in NBP, 137.5 +/- 7.9 vs 142.6 +/- 6.9 mmol/L, P less than 0.001. No difference was found between FH+ and FH-; (3) Mean 8-hour urinary K excretion at night was lower in HBP than in NBP, 23.9 +/- 11.5 vs. 28.2 +/- 14.7 mmol/g-creatinine, P less than 0.01; (4) After a load of oral saline the 4-hour urinary Na excretion was significantly higher in HBP than in NBP, 39.5 +/- 29.1 vs 30.8 +/- 23.2 mmol, P less than 0.01. Of those children with FH-, the 4-hour Na excretion in HBP was higher than in NBP, 39.8 +/- 29.4 vs 29.3 +/- 21.5 mmol, P less than 0.001, but no significant difference was found between HBP and NBP in children with FH+. We believed that the above changes in electrolytes in the children with their BP at higher-level percentiles represent an abnormal relation between potassium and arterial BP in the early stage of hypertension, as well as the early compensatory natriuresis of the kidneys.     

Blood pressure control in a hypertension hospital clinic.

OBJECTIVES: First, to evaluate the prevalence of clinic blood pressure (BP) control (BP < or = 140/90 mm Hg) in a representative sample of treated hypertensive patients followed in our hypertension clinic. Second, to assess in a subgroup of these patients: (a) the proportion of BP control with both clinic blood pressure (CBP < or =140/90 mm Hg) and daytime ambulatory blood pressure (ABP) (< or =132/85 mm Hg) criteria, and (b) the prevalence of echocardiographic left ventricular hypertrophy (LVH) (left ventricular mass index, LVMI>125 g/m2 in men and >110 g/m2 in women). DESIGN AND METHODS: Seven hundred consecutive hypertensive patients who attended our hypertension centre clinic during a period of 6 months and who had regularly been followed up by the same medical team were included in the study. BP was taken in the clinic by a doctor using a mercury sphygmomanometer with the participants seated. Seventy-four patients with similar demographic and clinical characteristics to the entire population of participants underwent complete echocardiographic examination and 24 h ABP monitoring. RESULTS: During follow-up, 352 of the treated patients had clinic BP < or =140/90 mm Hg, 198< or =160/95 mm Hg and 150>160/95 mm Hg, indicating that BP control was satisfactory in 50.3%, borderline in 28.3% and unsatisfactory in 21.4% of the cases. In the subgroup of 74 patients, the proportion of individuals with satisfactory clinic BP control (CBP< or =140/90 mm Hg) was higher (50.0 versus 33.6%) than with satisfactory ABP control (daytime ABP values < or =132/85 mm Hg). LVH was found in 21 of the 74 patients (28.3%): 12 of them had unsatisfactory CBP control and 19 had unsatisfactory ABP control. LVMI did not correlate with CBP values but only with ABP values (mean 24 h systolic r = 0.47, diastolic r = 0.40, P<0.001; mean daytime systolic r = 0.45, mean daytime diastolic r = 0.39, P<0.001; mean night-time systolic r = 0.38, mean night-time diastolic r = 0.38, P<0.001). CONCLUSION: This study demonstrates that hypertensive patients managed in a hypertension centre clinic have satisfactory CBP control in 50% of cases, but this rate seems to over-estimate the effective BP control during daily life. A large fraction of patients show persistence of LVH and this evidence of organ damage almost entirely concerns individuals with poor ABP control.