Device for the self-measurement of blood pressure that can monitor blood pressure during sleep

Proposal of reference value for day-to-day blood pressure variability based on two outcomes: the Ohasama study

BACKGROUND

This study aimed to propose reference values for day-to-day home blood pressure (BP) variability that align with the established hypertension threshold of home BP for the risk of two different outcomes: cardiovascular mortality and cognitive decline.

METHODS

This prospective study was conducted in Ohasama town, Japan, with 1212 participants assessed for cardiovascular mortality risk (age: 64.7 years, 33.6% men). Additionally, 678 participants (age: 62.7 years, 31.1% men) were assessed for cognitive decline risk (Mini-Mental Scale Examination score <24). The within-individual coefficient of variation of home morning SBP (HSBP) was used as the index of day-to-day BP variability (%). Adjusted Cox regression models were used to estimate the HSBP-CV values, which provided the 10-year outcome risk at an HSBP of 135 mmHg.

RESULTS

A total of 114 cardiovascular deaths and 85 events of cognitive decline (mean follow-up:13.9 and 9.6 years, respectively) were identified. HSBP and HSBP-coefficient of variation (HSBP-CV) were associated with increased risks for both outcomes, with adjusted hazard ratios per 1-standard deviation increase of at least 1.25 for cardiovascular mortality and at least 1.30 for cognitive decline, respectively. The adjusted 10-year risks for cardiovascular mortality and cognitive decline were 1.67 and 8.83%, respectively, for an HSBP of 135 mmHg. These risk values were observed when the HSBP-CV was 8.44 and 8.53%, respectively.

CONCLUSION

The HSBP-CV values indicating the 10-year risk of cardiovascular mortality or cognitive decline at an HSBP of 135 mmHg were consistent, at approximately 8.5%. This reference value will be useful for risk stratification in clinical practice.

Self-measured home blood pressure highlights cardiovascular risk in women: the HOMED-BP study

No studies examined sex differences in relation to the prognostic significance of self-measured home blood pressure (HBP). We compared the predictive power for the risk of cardiovascular events in 1547 women and 1516 men with hypertension using HBP captured at treatment-free baseline and during on-treatment follow-up, based on the Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study. To express the change in risk for the composite cardiovascular endpoint associated with a 1-SD increase in HBP at baseline or on treatment, we derived multivariable-adjusted hazard ratios (HR) based on a Cox regression model. Over a median follow-up of 7.3 years, 100 composite events occurred, including 40 events in women. In women, systolic HBP both at baseline and on-treatment showed significant risk increment (at baseline: HR per 1-SD increment, 1.62; 95% confidence interval [CI], 1.17-2.24. on-treatment: HR, 1.74; 95% CI, 1.32-2.29). However, systolic HBP at baseline did not predict cardiovascular events in men (P = 0.25). On-treatment HBP was significantly associated with cardiovascular risk (P ≤ 0.012) irrespective of sex. Nevertheless, the point estimate of HR for systolic HBP in men (1.33) was less than that in women (1.74), and the interaction of sex with 1 SD-increase in systolic HBP in cardiovascular risk was significant irrespective of baseline (P = 0.039) or follow-up (P = 0.040) measurement when they were mutually adjusted. The increase in cardiovascular risk with the systolic HBP was steeper in women than in men for both baseline and on-treatment. The current findings unveil the importance of the control of systolic HBP, especially in women. Clinical Trial Registration: UMIN Clinical Trial Registry ( http://www.umin.ac.jp/ctr ), Unique identifier: C000000137.

A personal history of research on hypertension From an encounter with hypertension to the development of hypertension practice based on out-of-clinic blood pressure measurements

In the 1970s, many people had severe hypertension and related cardiovascular and cerebrovascular diseases; however, antihypertensive treatments were not available at the time. The author encountered such conditions during the initial exposure to medicine. The author subsequently entered the field of hypertension medicine to prevent such conditions and engaged in hypertension research for more than 50 years. The author's central interest was the physiological and clinical aspects of blood pressure (BP) variability. Out-of-clinic BP measurements were the focus of clinical research. It was anticipated that self-measurement of BP at home (HBP) would improve medical practice surrounding hypertension. To establish evidence-based hypertension medicine, the Ohasama study (an epidemiology based on HBP) was conducted. The study provided firm evidence of the clinical significance of HBP and diagnostic criteria for hypertension and normotension. To establish target HBP levels for antihypertensive therapy, the Hypertension Objective treatment based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study (a prospective intervention study) was also conducted. Application of HBP measurements expanded to obstetric, clinical pharmacology, pathophysiology, and genetic studies. During these studies, crucial information on the clinical significance of BP variability (such as circadian and day-by-day variation of BP, nocturnal BP, white-coat hypertension, and masked hypertension) was established. Finally, the author described the priority of HBP over clinic-measured BP for the diagnosis of hypertension in the 2014 Japanese Society of Hypertension Guidelines. In this article, the author's history of hypertension research, from the first encounter with hypertension to the construction of guidelines on hypertension, is reviewed.

Association of home and office systolic and diastolic hypertension with glucose metabolism in a general population: the Ohasama study

OBJECTIVE

This study was performed to investigate the association of hypertension subtypes with glucose metabolism among the Japanese general population.

METHODS

The study involved 646 residents (mean age: 62.4 years) without treatment for hypertension or a history of diabetes from Ohasama, a rural Japanese community, who underwent an oral glucose tolerance test. Hypertension subtypes [normotension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic and diastolic hypertension (SDH)] were defined on the basis of home and office SBP and DBP (HBP and OBP, respectively). The estimated means of blood glucose related indices among the groups were compared by analysis of covariance adjusted for possible confounding factors.

RESULTS

Blood glucose related indices were not different among the morning HBP-defined hypertension subtypes. Participants with evening HBP-defined ISH had a significantly higher estimated mean BG at 120 min, higher homeostasis model assessment-insulin resistance (HOMA-IR) and lower Matsuda-DeFronzo index than participants with NT (all P < 0.021). Participants with OBP-defined SDH had a significantly higher estimated mean fasting blood glucose; blood glucose at 30, 60 and 120 min; and HOMA-IR and a lower Matsuda-DeFronzo index than participants with NT (all P < 0.0025).

CONCLUSION

The blood glucose related indices were different among hypertension subtypes. Participants with evening HBP-defined ISH and OBP-defined SDH had higher blood glucose levels and insulin resistance than participants with correspondingly defined normotension, while those with morning HBP did not. These findings suggest the importance of measuring evening HBP and office blood pressure for early detection of coexisting hypertension and diabetes.

Abnormal Circadian Blood Pressure Variation is Associated with SYNTAX Scores in Hospitalized Patients with Acute Coronary Syndrome

BACKGROUND

Blunted nocturnal blood pressure (BP) reduction, referred to as non-dipper hypertension, is a strong predictor of cardiovascular morbidity and mortality.

OBJECTIVES

This study aimed to investigate the relationship between non-dipper hypertension and the severity and complexity of coronary artery disease using SYNTAX score in hospitalized patients with acute coronary syndrome.

METHODS

A total of 306 consecutive patients with acute coronary syndrome were screened. Patients who were clinically stable and admitted to the intermediate intensive care unit at least 24 hours after angiography and/or successful revascularization. After the exclusion criteria, 141 patients (34 female and 107 male; mean age 61 ± 11 years) were included. Non-dipper hypertension has been defined as a 0% to 10% decrease in average systolic BP at nighttime compared to daytime, measured at hourly intervals using the same automatic BP measuring device on bedside monitors (Vismo PVM-2701; Nihon Kohden Corp., Tokyo, Japan). SYNTAX score was calculated with an online calculator. The independent predictors of SYNTAX score were assessed using multivariable logistic regression analysis. P < 0.05 was considered statistically significant.

RESULTS

The patients with non-dipper hypertension had higher SYNTAX score than the patients with dipper hypertension (11.12 ± 6.41 versus 6.74 ± 6.45, p < 0.0001). In a multivariable logistic regression model, non-dipper hypertension status (odds ratio: 5.159; 95% confidence interval: 2.246 to 11.852, p < 0.001), sex (p = 0.012) and low-density lipoprotein cholesterol (p = 0.008) emerged as independent predictors of high SYNTAX score.

CONCLUSIONS

The results of our study provide a possible additional mechanism linking abnormal circadian BP profile with coronary artery disease severity and complexity in patients with acute coronary syndrome.

Predictive power of home blood pressure in the evening compared with home blood pressure in the morning and office blood pressure before treatment and in the on-treatment follow-up period: a post hoc analysis of the HOMED-BP study

The predictive power of home blood pressure (BP) in the evening compared with home BP in the morning and office BP has been controversial. The predictive power of evening BP was compared to that of morning BP and office BP. The likelihood ratio test between one model containing a single BP index with traditional risk factors and a similar model further containing another BP index was used to assess whether the additional BP index significantly improved the adequacy of the model. Of 3266 patients with mild-to-moderate hypertension who were on antihypertensive medications (men 50.6%, age 59.5 ± 10.0 years), 58 experienced a major adverse cardiovascular event during a median follow-up of 7.1 years. The hazard ratios for a one standard deviation increment of evening home systolic/diastolic BP were 1.26 (0.98-1.62)/1.43 (1.09-1.88) in the baseline untreated period and 1.46 (1.17-1.81)/1.63 (1.26-2.11) during the on-treatment follow-up period. When evening BP at baseline and that during follow-up were included in the same model, only the latter significantly improved the prediction models (P = 0.006/0.005 for systolic/diastolic BP). Then, evening home BP vs. morning BP during follow-up was tested. The former did not improve the prediction models (P > 0.2), but the latter significantly improved the models (P ≤ 0.048). Similarly, when evening home BP and office BP during follow-up were analyzed, only the former significantly improved the prediction models (P ≤ 0.015). In conclusion, evening BP could be a more potent predictor than office BP, but it was inferior compared to morning BP in the treatment of mild-to-moderate hypertensive patients.

Effects of ambulatory blood pressure monitoring on sleep in healthy, normotensive men and women

OBJECTIVES

To determine the effect of ambulatory blood pressure monitoring (ABPM) on sleep quality among healthy adults and to explore possible effect modification by demographics.

METHODS

We examined data from 192 relatively healthy young (median age: 31; 33% men, 18% with clinic BP >130/80 mmHg) participants in an observational study of sleep and arterial stiffness. Demographic/health questionnaires were completed. A wrist-based accelerometer assessed sleep for seven nights, and sleep duration, wakefulness after sleep onset (WASO), fragmentation (physical restlessness), midpoint, and efficiency were estimated. ABPM was conducted for one 36-h period, including one actigraphy night.

RESULTS

Within-subject comparisons indicated that WASO and fragmentation were higher, midpoint was later, and efficiency was lower on the ABPM night (Ps < 0.001-0.038). Neither age nor sex moderated these associations. Among older adults, a later midpoint and worse fragmentation were observed with ABPM (Ps = 0.002-0.010). There was also a main effect of sex: men demonstrated shorter sleep duration, greater WASO and fragmentation, and less efficiency than women (Ps = 0.002-0.046). With ABPM, women had worse fragmentation and a later midpoint (Ps = 0.002-0.049); for men, WASO and fragmentation were worse (Ps = 0.003-0.023). Importantly, this study does not address whether the effect of wearing ABPM on sleep in turn affects BP during sleep.

CONCLUSIONS

ABPM appears to modestly disturb actigraphy-assessed sleep among healthy adults. Researchers and clinicians should consider the downstream effects of performing ABPM and whether these effects are more pronounced in those who typically experience sleep disturbance.

Clinical significance of nocturnal home blood pressure monitoring and nocturnal hypertension in Asia

Nocturnal home blood pressure (BP) monitoring has been used in clinical practice for ~20 years. The authors recently showed that nocturnal systolic BP (SBP) measured by a home BP monitoring (HBPM) device in a Japanese general practice population was a significant predictor of incident cardiovascular disease (CVD) events, independent of office and morning home SBP levels, and that masked nocturnal hypertension obtained by HBPM (defined as nocturnal home BP ≥ 120/70 mmHg and average morning and evening BP < 135/85 mmHg) was associated with an increased risk of CVD events compared with controlled BP (nocturnal home BP < 120/70 mmHg and average morning and evening BP < 135/85 mmHg). This evidence revealed that (a) it is feasible to use a nocturnal HBPM device for monitoring nocturnal BP levels, and (b) such a device may offer an alternative to ambulatory BP monitoring, which has been the gold standard for the measurement of nocturnal BP. However, many unresolved clinical problems remain, such as the measurement schedule and conditions for the use of nocturnal HBPM. Further investigation of the measurement of nocturnal BP using an HBPM device and assessments of the prognostic value are thus warranted. Asians are at high risk of developing nocturnal hypertension due to high salt sensitivity and salt intake, and the precise management of their nocturnal BP levels is important. Information and communication technology‐based monitoring devices are expected to facilitate the management of nocturnal hypertension in Asian populations.

Antihypertensive drug effects according to the pretreatment self-measured home blood pressure: the HOMED-BP study

OBJECTIVES

To clarify whether or not the antihypertensive drug effect is proportional to the baseline pretreatment self-measured home blood pressure (HBP) in accordance with the law of initial value (Wilder's law).

DESIGN

A post-hoc analysis of a multicentre clinical trial.

SETTING

Outpatients across Japan with mild-to-moderate essential hypertension.

PARTICIPANTS

Among 3518 randomised participants, 2423 who self-measured HBP during the pretreatment drug-free period (10-28 days after starting fixed-dose antihypertensive monotherapy) with a mean 7.0 years follow-up were eligible.

MAIN OUTCOME MEASURES

We analysed individual HBP readings during pretreatment and monotherapy.

RESULTS

The day-to-day HBP during both the pretreatment period and monotherapy period remains almost the same throughout each period; the results were consistent, regardless of the pretreatment HBP. Following monotherapy, the reduction in the HBP increased by 2.2 mm Hg (95% CI: 1.8 to 2.5 mm Hg) per 10 mm Hg pretreatment HBP increase, up to 11.0 mm Hg (95% CI: 9.9 to 12.0 mm Hg) among patients with an HBP ≥165 mm Hg during pretreatment. Among the 1005 patients receiving low-dose monotherapy (defined daily dose: 0.5 units), the reduction peaked at 8.9-9.1 mm Hg in those with pretreatment HBP 155-164 mm Hg and ≥165 mm Hg (p=0.88).

CONCLUSIONS

According to Wilder's law, the HBP reduction due to fixed-dose monotherapy was proportional to the pretreatment HBP without any regression to the mean phenomenon. With low-dose antihypertensive drugs, however, the HBP reduction peaked in patients with a high pretreatment HBP, indicating the need for such patients to receive a sufficient amount of antihypertensive drug medication at the initial treatment.

TRIAL REGISTRATION

UMIN Clinical Trial Registry (http://www.umin.ac.jp/ctr), Unique identifier: C000000137.

The Role of Nocturnal Blood Pressure and Sleep Quality in Hypertension Management

The accurate measurement, prediction and treatment of high blood pressure (BP) are essential to the management of hypertension and the prevention of its associated cardiovascular (CV) risks. However, even if BP is optimally controlled during the day, nocturnal high blood pressure may still increase the risk of CV events. The pattern of circadian rhythm of BP can be evaluated by ambulatory BP monitoring (ABPM). Night-time ABPM is more closely associated with fatal and nonfatal CV events than daytime ambulatory BP. However, the use of ABPM is limited by low availability and the fact that it can cause sleep disturbance, therefore may not provide realistic nocturnal measurements. Home blood pressure monitoring (HBPM) offers an inexpensive alternative to ABPM, is preferred by patients and provides a more realistic assessment of BP during an individual’s daily life. However, until recently, HBPM did not offer the possibility to measure nocturnal (sleep time) BP. The development and validation of new BP devices, such as the NightView (OMRON Healthcare, HEM9601T-E3) HBPM device, could overcome these limitations, offering the possibility of daytime and night-time BP measurements with minimal sleep disturbance.

Recent status of self-measured home blood pressure in the Japanese general population: a modern database on self-measured home blood pressure (MDAS)

Despite the clinical usefulness of self-measured home blood pressure (BP), reports on the characteristics of home BP have not been sufficient and have varied due to the measurement conditions in each study. We constructed a database on self-measured home BP, which included five Japanese general populations as subdivided aggregate data that were clustered and meta-analyzed according to sex, age category, and antihypertensive drug treatment at baseline (treated and untreated). The self-measured home BPs were collected after a few minutes of rest in a sitting position: (1) the morning home BP was measured within 1 h of waking, after urination, before breakfast, and before taking antihypertensive medication (if any); and (2) the evening home BP was measured just before going to bed. The pulse rate was simultaneously measured. Eligible data from 2000 onward were obtained. The morning BP was significantly higher in treated participants than in untreated people of the same age category, and the BP difference was more marked in women. Among untreated residents, home systolic/diastolic BPs measured in the morning were higher than those measured in the evening; the differences were 5.7/5.0 mmHg in women (ranges across the cohorts, 5.3-6.8/4.7-5.4 mmHg) and 7.3/7.7 mmHg in men (ranges, 6.4-8.5/7.0-8.7 mmHg). In contrast, the home pulse rate in women and men was 2.4 (range, 1.5-3.7) and 5.6 (range, 4.6-6.6) beats per minute, respectively, higher in the evening than in the morning. We demonstrated the current status of home BP and home pulse rate in relation to sex, age, and antihypertensive treatment status in the Japanese general population. The approach by which fine-clustered aggregate statistics were collected and integrated could address practical issues raised in epidemiological research settings.

Direct Comparison of Home Versus Ambulatory Defined Nocturnal Hypertension for Predicting Cardiovascular Events

The home blood pressure monitoring (HBPM) method that measures blood pressure during sleep hours was reported to be comparable to ambulatory blood pressure monitoring (ABPM) in measuring nighttime blood pressure and detecting nocturnal hypertension. The aim of this study was to directly compare the prognostic power of nocturnal hypertension detected by HBPM versus ABPM for predicting future cardiovascular events. We analyzed nighttime blood pressure (measured by HBPM and ABPM) data of 1005 participants who were included in the J-HOP study (Japan Morning Surge-Home Blood Pressure). During a follow-up period of 7.6±3.4 years, 80 cardiovascular disease events occurred. The majority (91.8%) of our study population were hypertensive, and 80.7% of participants were using antihypertensive medication. Nighttime home systolic blood pressure (SBP) was higher compared to nighttime ambulatory SBP (123.0±14.6 versus 120.3±14.4 mm Hg, P <0.001). Nocturnal hypertension was defined as nighttime home or ambulatory SBP of ≥120 mm Hg. The number of participants with nocturnal hypertension defined by HBPM and ABPM was 564 (56.1%) and 469 (46.7%), respectively. Nocturnal hypertension defined by HBPM was associated with increased risk of future cardiovascular events: total cardiovascular events (coronary artery disease and stroke events; 1.78 [1.00–3.15]) and stroke (2.65 [1.14–6.20]), independent of office SBP. These results were absent with nocturnal hypertension defined by ABPM. This is the first comparison prospective study illustrating that uncontrolled nocturnal hypertension defined by HBPM (independent of office SBP) is a predictor of future cardiovascular events.

Nocturnal blood pressure measured by home devices: evidence and perspective for clinical application

: Studies using ambulatory blood pressure (BP) monitoring have shown that BP during night-time sleep is a stronger predictor of cardiovascular outcomes than daytime ambulatory or conventional office BP. However, night-time ambulatory BP recordings may interfere with sleep quality because of the device cuff inflation and frequency of measurements. Hence, there is an unmet need for obtaining high quality BP values during sleep. In the last two decades, technological development of home BP devices enabled automated BP measurements during night-time. Preliminary data suggest that nocturnal home BP measurements yield similar BP values and show good agreement in detecting nondippers when compared with ambulatory BP monitoring. Thus, nocturnal home BP measurements might be a reliable and practical alternative to ambulatory BP monitoring to evaluate BP during sleep. As the use of home BP devices is widespread, well accepted by users and has relatively low cost, it may prove to be more feasible and widely available for routine clinical assessment of nocturnal BP. At present, however, data on the prognostic relevance of nocturnal BP measured by home devices, the optimal measurement schedule, and other methodological issues are lacking and await further investigation. This article offers a systematic review of the current evidence on nocturnal home BP, highlights the remaining research questions, and provides preliminary recommendations for application of this novel approach in BP management.

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.

Nighttime Blood Pressure Measured by Home Blood Pressure Monitoring as an Independent Predictor of Cardiovascular Events in General Practice

We developed an innovative automated home blood pressure (BP) monitoring method that measures BP while asleep repeatedly over several days. Our aim was to assess the predictive ability of nighttime BP obtained using the home BP device for incident cardiovascular disease (CVD) in general practice patients. We used data from the nationwide practice-based J-HOP (Japan Morning Surge-Home Blood Pressure) Nocturnal BP Study, which recruited 2545 Japanese with a history of or risk factors for CVD (mean age 63 years; antihypertensive medication use 83%). The associations between nighttime home BPs (measured at 2:00, 3:00, and 4:00 am using validated, automatic, and oscillometric home BP devices) and incident CVD, including coronary disease and stroke events, were assessed with Cox proportional hazards models. The mean±SD office, morning home, and nighttime home systolic BP (SBP)/diastolic BP were 140±15/82±10, 137±15/79±10, and 121±15/70±9 mm Hg, respectively. During a follow-up of 7.1±3.8 years (18,116 person-years), 152 CVD events occurred. A 10-mm Hg increase of nighttime home SBP was associated with an increased risk of CVD events (hazard ratios [95% CIs]: 1.201 [1.046-1.378]), after adjustments for covariates including office and morning home SBPs. The model fit assessed by the change in Goodness-of-Fit was improved when we added nighttime home SBP into the base models including office and morning home SBPs (Δ6.838 [5.6%]; P=0.009). This is among the first and largest nationwide practice-based study demonstrating that nighttime SBP obtained using a home device is a predictor of incident CVD events, independent of in-office and morning in-home SBP measurement. Clinical Trial Registration- URL: http://www.umin.ac.jp/icdr/index.html . Unique identifier: UMIN000000894.

Agreement Between Ambulatory and Home Blood Pressure Monitoring in Detecting Nighttime Hypertension and Nondipping Patterns in the General Population

BACKGROUND

Nighttime blood pressure (BP) and nondipping pattern are strongly associated with hypertensive end-organ damage. However, no previous studies have compared the diagnostic agreement between ambulatory and home monitoring in detecting these BP patterns in the general population.

METHODS

We studied a population-based sample of 180 persons aged 32-80 years. The study protocol included 24-hour ambulatory BP monitoring, home daytime measurements over 7 days, home nighttime measurements (6 measurements over 2 consecutive nights using a timer-equipped home device), and ultrasound measurements for left ventricular mass index (LVMI) and carotid intima-media thickness (IMT). We defined nondipping as a <10% reduction in nighttime BP compared with daytime BP, and nighttime hypertension as BP ≥ 120/70 mm Hg.

RESULTS

The agreement between ambulatory and home monitoring for detecting nighttime hypertension was good (80%, κ = 0.56, P < 0.001). However, their agreement in detecting nondipping status was poor (54%, κ = 0.12, P = 0.09). The magnitude of ambulatory systolic BP dipping percent was 1.7% higher than on home monitoring (P = 0.004), whereas no difference was observed for diastolic BP dipping (difference: 0.7%, P = 0.33). LVMI and IMT were significantly greater among individuals with nighttime hypertension than in normotensive individuals, irrespective of the measurement method. However, only ambulatory nondippers, but not home nondippers, had more advanced end-organ damage than dippers.

CONCLUSION

We observed a good agreement between ambulatory and home BP monitoring in detecting nighttime hypertension in the general population. Two-night home monitoring could offer an inexpensive and feasible method for the diagnosis of nighttime hypertension.

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-9600T

The purpose of the present study was to evaluate the performance of the Omron HEM-9600T, an automatic wrist-type device for self BP measurement, in the sitting position with the wrist at heart level and supine position according to the ANSI/AAMI/ISO81060-2:2013 guidelines. In the supine position, we evaluated the device under 3 different conditions: using the supine with sideways palm position, the supine with upwards palm position, and the supine with downwards palm position. After 106 subjects were screened and 21 subjects were excluded, the same 85 subjects (38 men [44.7%] and 47 women [55.3%]) were included in the analyses for each position. The average age of the subjects was 54.5 ± 12.2 years (mean ± SD). The mean wrist circumference was 17.0 ± 2.4 cm. The wrist size distribution fulfilled the requirements of the guidelines. The mean differences between reference BPs and HEM-9600T readings were 1.0 ± 6.7/1.4 ± 5.7 mm Hg, 6.6 ± 7.2/5.5 ± 6.0 mm Hg, 4.8 ± 7.2/4.9 ± 5.8 mm Hg, and 2.1 ± 7.2/2.8 ± 6.8 mm Hg for SBP/DBP in the sitting position, supine with sideways palm position, supine with upwards palm position, and supine with downwards palm position, respectively. In conclusion, the Omron HEM-9600T in the sitting position fulfilled the validation criteria of the ANSI/AAMI/ISO81060-2:2013 guidelines. On the other hand, the accuracies of HEM-9600T in the supine position differed depending on the positioning of the palm, with only the downwards palm-position measurement fulfilling both validation criteria of the ANSI/AAMI/ISO81060-2:2013 guidelines.

Understanding short-term blood-pressure-variability phenotypes: from concept to clinical practice

Clinic blood pressure (BP) is recognized as the gold standard for the screening, diagnosis, and management of hypertension. However, optimal diagnosis and successful management of hypertension cannot be achieved exclusively by a handful of conventionally acquired BP readings. It is critical to estimate the magnitude of BP variability by estimating and quantifying each individual patient's specific BP variations. Short-term BP variability or exaggerated circadian BP variations that occur within a day are associated with increased cardiovascular events, mortality and target-organ damage. Popular concepts of BP variability, including "white-coat hypertension" and "masked hypertension", are well recognized in clinical practice. However, nocturnal hypertension, morning surge, and morning hypertension are also important phenotypes of short-term BP variability that warrant attention, especially in the primary-care setting. In this review, we try to theorize and explain these phenotypes to ensure they are better understood and recognized in day-to-day clinical practice.

Predictive power of home blood pressure indices at baseline and during follow-up in hypertensive patients: HOMED-BP study

We compared the predictive power for a major adverse cardiovascular event (MACE) of four home blood pressure (BP) indices (systolic BP, diastolic BP, mean BP, and pulse pressure (PP)) obtained at baseline before treatment and during the on-treatment follow-up period in 3147 patients with essential hypertension (women: 50.1%, mean age: 59.5 years). Associations between MACE and each index were determined using Cox proportional hazard models and the likelihood ratio (LR) test. During a median follow-up of 5.4 years, 46 patients experienced MACE, which was a composite of cardiovascular death, non-fatal stroke, and non-fatal myocardial infarction. The LR test showed that systolic, diastolic, and mean BP during follow-up was more closely associated with cardiovascular risk than the corresponding indices at baseline (LR χ² for baseline versus follow-up: systolic BP, (6.0, P = 0.014) versus (11.3, P = 0.0008); diastolic BP, (0.4, P = 0.53) versus (12.4, P = 0.0004); mean BP, (3.2, P = 0.074) versus (15.0, P = 0.0001)), whereas neither PP at baseline nor that during follow-up was significantly associated with MACE risk. Among home BP indices during follow-up, mean BP further improved prediction models in which systolic or diastolic BP was already included (P ≤ 0.042), but neither systolic nor diastolic BP improved models with mean BP (P = 0.80). In addition to home systolic and diastolic BP, mean BP during follow-up period provides essential information in predicting future cardiovascular diseases, whereas its utilization should be further assessed by an intervention trial targeting mean BP levels.

Diurnal blood pressure changes

The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

Association Between Amplitude of Seasonal Variation in Self-Measured Home Blood Pressure and Cardiovascular Outcomes: HOMED-BP (Hypertension Objective Treatment Based on Measurement By Electrical Devices of Blood Pressure) Study

Background

The clinical significance of long‐term seasonal variations in self‐measured home blood pressure (BP) has not been elucidated for the cardiovascular disease prevention.

Methods and Results

Eligible 2787 patients were classified into 4 groups according to the magnitude of their seasonal variation in home BP, defined as an average of all increases in home BP from summer (July–August) to winter (January–February) combined with all decreases from winter to summer throughout the follow‐up period, namely inverse‐ (systolic/diastolic, <0/<0 mm Hg), small‐ (0–4.8/0–2.4 mm Hg), middle‐ (4.8–9.1/2.4–4.5 mm Hg), or large‐ (≥9.1/≥4.5 mm Hg) variation groups. The overall cardiovascular risks illustrated U‐shaped relationships across the groups, and hazard ratios for all cardiovascular outcomes compared with the small‐variation group were 3.07 (P=0.004) and 2.02 (P=0.041) in the inverse‐variation group and large‐variation group, respectively, based on systolic BP, and results were confirmatory for major adverse cardiovascular events. Furthermore, when the summer‐winter home BP difference was evaluated among patients who experienced titration and tapering of antihypertensive drugs depending on the season, the difference was significantly smaller in the early (September–November) than in the late (December–February) titration group (3.9/1.2 mm Hg versus 7.3/3.1 mm Hg, P<0.001) as well as in the early (March–May) than in the late (June–August) tapering group (4.4/2.1 mm Hg versus 7.1/3.4 mm Hg, P<0.001).

Conclusions

The small‐to‐middle seasonal variation in home BP (0–9.1/0–4.5 mm Hg), which may be partially attributed to earlier adjustment of antihypertensive medication, were associated with better cardiovascular outcomes.

Genome-wide association study for white coat effect in Japanese middle-aged to elderly people: The HOMED-BP study

BACKGROUND

White coat effect (WCE), the blood pressure (BP) difference between clinical and non-clinical settings, can lead to clinical problems such as misdiagnosis of hypertension. Etiology of WCE has been still unclear, especially from genetic aspects. The present article investigated association between genome-wide single nucleotide polymorphisms (SNPs) and WCE in patients with essential hypertension.

METHODS

The present cross-sectional analyses were based on 295 Japanese essential hypertensive outpatients aged ≧40 years enrolled in randomized control study, Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study, who were not taking antihypertensive medications before the randomization. Home and clinic BP were measured. WCE was defined by subtracting home BP from clinic BP. Genotyping was conducted with 500K DNA microarray chips. Association between genome-wide SNPs and WCE were analyzed. For replication (p < 10^-4), we analyzed participants from Ohasama study who took no antihypertension medications and whose SNPs were collected.

RESULTS

Genome-wide SNPs were not significantly associated with WCE of systolic and diastolic BP after corrections of multiple comparisons (p < 2 × 10^-7). We found suggestive SNPs associated with WCE of systolic and diastolic BP (p < 10^-4). However, the consistent results were not obtained in the replication study.

CONCLUSION

The present article showed no significant association between genome-wide SNPs and WCE. Since there were several suggestive SNPs associated with WCE, the present study warrants a further study with bigger sample size for investigating the genetic influence on WCE.

The velocity of antihypertensive effects of seven angiotensin II receptor blockers determined by home blood pressure measurements

BACKGROUND

We aimed to examine the blood pressure (BP)-lowering effect and the time to attain the maximal antihypertensive effect (stabilization time) of several angiotensin II receptor blockers (ARBs) based on home BP measurements.

METHODS

We surveyed consecutive newly diagnosed, untreated patients with hypertension who started the treatment with a mid-level dose of one of seven ARBs (losartan 50 mg, telmisartan 40 mg, candesartan 8 mg, olmesartan 20 mg, valsartan 80 mg, irbesartan 100 mg, or azilsartan 20 mg). All study participants measured home BP in the morning for at least 1 week during an untreated period and 4 weeks during the treatment period.

RESULTS

Age, the proportion of men, and baseline home BP levels did not differ significantly between groups (total n = 232; age, 62.2 years; 50.9% men; home SBP/DBP, 151.6/90.0 mmHg). Significant differences in the BP-lowering effect and the stabilization time between ARBs were observed (P ≤ 0.02). The extent of BP-lowering effects of azilsartan 20 mg was significantly greater than that of valsartan 80 mg or irbesartan 100 mg (15.3 vs. 7.9 or 8.2 mmHg, respectively P ≤ 0.03). The stabilization time of losartan for home SBP was significantly longer than that of valsartan, irbesartan, or azilsartan (22.8 vs. 7.1, 4.7, or 7.1 days, respectively, P ≤ 0.01).

CONCLUSION

The maximum effect and the stabilization time differed among ARBs used at the mid-level dose in Japan. An ARB should be chosen based on its desired characteristics.

Left ventricular hypertrophy by electrocardiogram as a predictor of success in home blood pressure control: HOMED-BP study

Few studies have focused on the effect of organ damage on achievement of long-term home blood pressure (BP) control. Based on the nationwide home BP-based trial data, we aimed to investigate the factors associated with home BP control, in particular, left ventricular hypertrophy (LVH) using the electrocardiogram in patients who started antihypertensive drug treatment. According to the trial protocol, we defined BP as controlled when systolic home BP reached specified targets (125-134 mm Hg in usual control (UC), n=1261; <125 mm Hg in tight control (TC), n=1288). At baseline, before drug treatment started, the mean Sokolow-Lyon voltage was 2.57±0.87 mV, and the mean Cornell product was 1573±705 mm·ms. The numbers of patients who achieved the target BP level in the UC and TC groups were 892 (70.7%) and 576 (44.7%), respectively. In both the UC and TC groups, systolic home BP at baseline was significantly lower in patients who achieved target levels than in those who did not achieve target levels (P<0.0001). Sokolow-Lyon voltage was significantly lower in patients who achieved target levels than in those who did not (P⩽0.0055). The Cornell product levels in each group were similar (P⩾0.12), although significantly different between patients who did or did not achieve the target level when the UC and TC groups were combined for analysis (P=0.031). Sokolow-Lyon voltage was significantly associated with achievement of home BP control in the multivariable-adjusted model (odds ratio, 1.13; 95% confidence intervals, 1.02-1.26; P=0.015), but Cornell product was not (P=0.13). These results indicate the difficulty of sufficient antihypertensive treatment when untreated patients had target organ damage, that is, LVH diagnosed by Sokolow-Lyon voltage.

Night-time home versus ambulatory blood pressure in determining target organ damage

OBJECTIVE

This study aimed to evaluate the association of night-time blood pressure (BP) assessed by home blood pressure (HBP) or ambulatory blood pressure (ABP) monitoring with preclinical target organ damage in untreated hypertension.

METHODS

Untreated hypertensive study participants were evaluated with ABP monitoring (24-h) and HBP monitoring during daytime (6 days, duplicate morning and evening measurements) and night-time (automated asleep measurements, three nights, 3-hourly measurements/night). Target organ damage was assessed by echocardiographic left ventricular mass index (LVMI), common carotid intima-media thickness (cIMT), urine albumin excretion (UAE), and ankle-brachial index (ABI).

RESULTS

A total of 131 study participants were analysed [mean age 52.1 ± 11.9 (SD) years, BMI 29.9 ± 5.3  kg/m2, men 58%, cardiovascular disease history 6.1%]. Daytime and night-time HBP were slightly higher than the respective ABP values (mean difference for systolic daytime/night-time 3.5 ± 10.6/2.6 ± 9.8  mmHg, P < 0.01 for both comparisons and diastolic -0.3 ± 6.8/1.2 ± 6.2  mmHg, P = NS/0.02, respectively). There was a strong correlation between daytime ABP and HBP (r = 0.71/0.72, systolic/diastolic), as well as between the respective night-time values (r = 0.80/0.79; all P < 0.01). Night-time ABP and HBP presented strong and comparable correlations with all the indices of preclinical target organ damage. In multivariate analyses, both LVMI (R2 = 0.26) and cIMT (R2 = 0.25) were determined by night-time systolic HBP, age and male sex; UAE (R2 = 0.28) by night-time systolic HBP and male sex; ABI (R2 = 0.20) by male sex and night-time home pulse pressure.

CONCLUSION

In untreated hypertensives, night-time BP assessed by home monitoring appears to be as good as night-time ambulatory monitoring in determining preclinical target organ damage.

Does Antihypertensive Drug Class Affect Day-to-Day Variability of Self-Measured Home Blood Pressure? The HOMED-BP Study

Background

Recent literature suggests that blood pressure variability (BPV) predicts outcome beyond blood pressure level (BPL) and that antihypertensive drug classes differentially influence BPV. We compared calcium channel blockers, angiotensin‐converting enzyme inhibitors, and angiotensin receptor blockade for effects on changes in self‐measured home BPL and BPV and for their prognostic significance in newly treated hypertensive patients.

Methods and Results

We enrolled 2484 patients randomly allocated to first‐line treatment with a calcium channel blocker (n=833), an angiotensin‐converting enzyme inhibitor (n=821), or angiotensin receptor blockade (n=830). Home blood pressures in the morning and evening were measured for 5 days off treatment before randomization and for 5 days after 2 to 4 weeks of randomized drug treatment. We assessed BPL and BPV changes as estimated by variability independent of the mean and compared cardiovascular outcomes. Home BPL response in each group was significant (P≤0.0001) but small in the angiotensin‐converting enzyme inhibitor group (systolic/diastolic: 4.6/2.8 mm Hg) compared with the groups treated with a calcium channel blocker (systolic/diastolic: 8.3/3.9 mm Hg) and angiotensin receptor blockade (systolic/diastolic: 8.2/4.5 mm Hg). In multivariable adjusted analyses, changes in home variability independent of the mean did not differ among the 3 drug classes (P≥0.054). Evening variability independent of the mean before treatment significantly predicted hard cardiovascular events independent of the corresponding home BPL (P≤0.022), whereas BPV did not predict any cardiovascular outcome based on the morning measurement (P≥0.056). Home BPV captured after monotherapy had no predictive power for cardiovascular outcome (P≥0.22).

Conclusions

Self‐measured home evening BPV estimated by variability independent of the mean had prognostic significance, whereas antihypertensive drug classes had no significant impact on BPV changes. Home BPL should remain the primary focus for risk stratification and treatment.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000137.

Sleep Blood Pressure Self-Measured at Home as a Novel Determinant of Organ Damage: Japan Morning Surge Home Blood Pressure (J-HOP) Study

To study whether sleep blood pressure (BP) self-measured at home is associated with organ damage, the authors analyzed the data of 2562 participants in the J-HOP study who self-measured sleep BP using a home BP monitoring (HBPM) device, three times during sleep (2 am, 3 am, 4 am), as well as the home morning and evening BPs. The mean sleep home systolic BPs (SBPs) were all correlated with urinary albumin/creatinine ratio (UACR), left ventricular mass index (LVMI), brachial-ankle pulse wave velocity (baPWV), maximum carotid intima-media thickness, and plasma N-terminal pro-hormone pro-brain-type natriuretic peptide (NTproBNP) (all P<.001). After controlling for clinic SBP and home morning and evening SBPs, associations of home sleep SBP with UACR, LVMI, and baPWV remained significant (all P<.008). Even in patients with home morning BP <135/85 mm Hg, 27% exhibited masked nocturnal hypertension with home sleep SBP ≥120 mm Hg and had higher UACR and NTproBNP. Masked nocturnal hypertension, which is associated with advanced organ damage, remains unrecognized by conventional HBPM.

Clinical significance of home blood pressure measurements for the prevention and management of high blood pressure

1. Ambulatory blood pressure (ABP) monitoring (M) provides BP information at many points on any particular day during unrestricted routine daily activities, whereas home blood pressure (HBP) monitoring provides a lot of BP information obtained under fixed times and conditions over a long period of time, thus mean values of HBP provide high reproducibility, and thus an overall superiority compared with ABP.  2. HBP is at least equally or better able than ABP to predict hypertensive target organ damage and prognosis of cardiovascular disease.  3. HBPM allows for ongoing disease monitoring by patients, improves adherence to antihypertensive treatment, and can provide health-care providers with timely clinical data and direct and immediate feedback regarding diagnosis and treatment of hypertension.  4. HBPM provides BP information in relation to time; that is, BP in the morning, in the evening and at night during sleep, and it is an essential tool for the diagnosis of white-coat and masked hypertension.  5. HBPM yields minimal alerting affects and no or minimal placebo effect, and can therefore distinguish small, but significant, serial changes in BP. It is thus the most practical method for monitoring BP in the day-to-day management of hypertension. 6. The superiority of HBPM over ABPM and clinic BPM is apparent from almost all practical and clinical research perspectives.

Practical use of home blood pressure monitoring in chronic kidney disease

Despite the availability of blood pressure (BP)-lowering medications and dietary education, hypertension is still poorly controlled in the chronic kidney disease (CKD) population. As glomerular filtration rate declines, the number of medications required to achieve BP targets increases, which may lead to reduced patient adherence and therapeutic inertia by the clinician. Home BP monitoring (HBPM) has emerged as a means of improving diagnostic accuracy, risk stratification, patient adherence, and therapeutic intervention. The definition of hypertension by HBPM is an average BP >135/85 mm Hg. Twelve readings over the course of 3-5 days are sufficient for clinical decision making. Diagnostic accuracy is especially important in the CKD population as approximately half of these patients have either white coat hypertension or masked hypertension. Preliminary data suggest that HBPM outperforms office BP monitoring in predicting progression to end-stage renal disease or death. When combined with additional support such as telemonitoring, medication titration, or behavioral therapy, HBPM results in a sustained improvement in BP control. HBPM must be adapted to provide information on the phenomena of nondipping (absence of nocturnal fall in BP) and reverse dipping (paradoxical increase in BP at night). These diurnal patterns are more prevalent in the CKD population and are important cardiovascular risk factors. Ambulatory BP monitoring provides nocturnal BP readings and unlike HBPM may be reimbursed by Medicare when certain criteria are met. Further studies are needed to determine whether HBPM is cost-effective in the current US healthcare system.

Genome-wide response to antihypertensive medication using home blood pressure measurements: a pilot study nested within the HOMED-BP study

BACKGROUND

Patients with mild-to-moderate essential hypertension in the HOMED-BP trial were randomly allocated to first-line treatment with a calcium channel blocker (CCB), angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB).

METHODS

We recruited 265 (93 for CCB, 71 for ACEI and 101 for ARB) patients who completed the genomic study. Home blood pressure was measured for 5 days off-treatment before randomization and for 5 days after 2-4 weeks of randomized drug treatment. Genotyping was performed by 500K DNA microarray chips. The blood pressure responses to the three drugs were analyzed separately as a quantitative trait. For replication of SNPs with p < 10(-4), we used the multicenter GEANE study, in which patients were randomized to valsartan or amlodipine.

RESULTS

SNPs in PICALM, TANC2, NUMA1 and APCDD1 were found to be associated with CCB responses and those in ABCC9 and YIPF1 were found to be associated with ARB response with replication.

CONCLUSION

Our approach, the first based on high-fidelity phenotyping by home blood pressure measurement, might be a step in moving towards the personalized treatment of hypertension.

Estimate of nocturnal blood pressure and detection of non-dippers based on clinical or ambulatory monitoring in the inpatient setting

BACKGROUND

Ambulatory blood pressure monitoring is regarded as the gold standard for monitoring nocturnal blood pressure (NBP) and is usually performed out of office. Currently, a novel method for monitoring NBP is indispensible in the inpatient setting. The widely used manual BP monitoring procedure has the potential to monitor NBP in the hospital setting. The feasibility and accuracy of manual sphygmomanometer to monitor NBP has not been explored widely.

METHODS

A cross-sectional study was conducted at the cardiology department of a university-affiliated hospital to study patients with mild-to-moderate essential hypertension. One hundred and fifty-five patients were recruited to compare BP derived from a manual device and ambulatory BP monitoring (ABPM). The manual BP measurement was performed six times at 22:00, 02:00, 06:00, 10:00, 14:00 and 18:00 h. The measurements at 22:00, 02:00 and 06:00 h were defined as night-time and the others as daytime. ABPM was programmed to measure at 30-min intervals between measurements.

RESULTS

All-day, daytime and night-time BP did not differ significantly from 24-h ambulatory systolic BP [all-day mean difference -0.52±4.67 mmHg, 95% confidence interval (CI) -1.26 to 0.22, P=0.168; daytime mean difference 0.24±5.45 mmHg, 95% CI -0.62 to 1.11, P=0.580; night-time mean difference 0.30±7.22 mmHg, 95% CI -0.84 to 1.45, P=0.601) rather than diastolic BP. There was a strong correlation between clinical and ambulatory BP for both systolic and diastolic BP. On the basis of ABPM, 101 (65%) patients were classified as non-dippers, compared with 106 (68%) by manual sphygmomanometer (P<0.001).

CONCLUSIONS

Traditional manual sphygmomanometer provides similar daytime and night-time systolic BP measurements in hospital. Moreover, the detection of non-dippers by manual methods is in good agreement with 24-h ABPM. Further studies are required to confirm the clinical relevance of these findings by comparing the association of NBP in the hospital ward assessed by manual monitoring with preclinical organ damage and cardiovascular and cerebrovascular outcomes.

The dilemma of nocturnal blood pressure

During the past decades, blood pressure (BP) measurement technique has evolved rapidly from the traditionally manual measuring to fully automatic monitoring. In terms of management of BP, there have been tremendous changes from the controlling of daytime BP, nondipping pattern to nocturnal BP (NBP). Since the focus has turned to NBP, a number of dilemmas of NBP measurement have gradually emerged in clinical practice and research settings, including methods for monitoring NBP, different period definition of nocturnal time, different diagnostic thresholds of abnormal NBP, whether to control abnormal NBP, and how to manage abnormal NBP. Currently, these issues have hindered progress in the appropriate management of hypertensive patients. Therefore, the purpose of this review is to concisely discuss the dilemmas of NBP.

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

BACKGROUND

A 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.

METHODS

Eighty-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.

RESULTS

Strong 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).

CONCLUSIONS

HBP 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.