Polysomnography-derived sleep parameters as a determinant of nocturnal blood pressure profile in patients with obstructive sleep apnea

Pregnancy-onset obstructive sleep apnea and ambulatory blood pressure

STUDY OBJECTIVE

Elevated nocturnal blood pressure (BP) increases the risk for hypertensive disorders of pregnancy (HDP). Though obstructive sleep apnea (OSA) increases the risk for HDP, data on OSA, and 24-hour ambulatory blood pressure monitoring (ABPM) in pregnancy are scarce. We aim to examine the BP profile of women with pregnancy-onset OSA.

METHODS

Pregnant women with overweight/obesity and snoring were recruited at <13 weeks gestation and underwent level III home sleep apnea testing and 24-hour ABPM at enrollment and at 31-34 weeks' gestation. Women with OSA at enrollment were excluded. Mean differences in nocturnal BP and 24-hour BP measurements, between women with pregnancy-onset OSA and women without OSA, were computed by multivariable linear regression.

RESULTS

Participants (40/101) had pregnancy-onset OSA (respiratory event index (REI) ≥5 events per hour) in the third trimester. Despite no significant differences in baseline BP, nocturnal systolic and diastolic BP were significantly higher in women with pregnancy-onset OSA compared to women without OSA, after adjusting for multiple covariates (mean difference 5.49 (1.45-9.52) and 3.89 (0.19-7.60), respectively). Differences in systolic BP persisted into the daytime in the OSA group. Lack of nocturnal dipping was highly prevalent in both groups, but the difference was not significant in the adjusted model.

CONCLUSIONS

Pregnancy-onset OSA in the 3rd trimester is associated with elevated nocturnal BP and daytime systolic BP. The lack of nocturnal dipping irrespective of REI cut-off in pregnant women at risk for SDB further demonstrates the limitations of REI in defining pathology in pregnancy.

Blood Pressure Regulation and Hypertension in Obstructive Sleep Apnea Syndrome: A Historical Perspective

In obstructive sleep apnea syndrome (OSAS), an underlying disease of secondary hypertension, repeated episodes of asphyxia due to obstructive sleep apnea (OSA), followed by arousal, lead to various cardiovascular consequences. Using a canine model of OSAS, it was found that a single load of OSA caused an abrupt increase in blood pressure (BP) (Apnea Surge in seconds), while multiple OSA episodes occurring nightly for 1-3 months led to a sustained elevation of BP during both nighttime and daytime. Epidemiological studies on 24-hour ambulatory BP measurements revealed that some hypertensive patients experienced elevated BP in the early morning (Morning Surge), which could be intensified by OSAS. The resonance of Apnea Surge in seconds and Morning Surge increases the risk of organ damage, triggers the cardiovascular events, and adversely affects the prognosis of hypertensive patients with OSAS. For ameliorating these risks, OSA should be treated with positive airway pressure properly.

Performance of a commercial smart watch compared to polysomnography reference for overnight continuous oximetry measurement and sleep apnea evaluation

STUDY OBJECTIVES

We evaluated the accuracy and precision of continuous overnight oxygen saturation (SpO2) measurement by a commercial wrist device (WD) incorporating high-grade sensors and investigated WD estimation of sleep-disordered breathing by quantifying overnight oxygen desaturation index compared to polysomnography (PSG) oxygen desaturation index and apnea-hypopnea index (AHI) with and without sleep questionnaire data to assess the WD's ability to detect obstructive sleep apnea and determine its severity.

METHODS

Participants completed sleep questionnaires, had a WD (Samsung Galaxy Watch 4) placed on their wrist, and underwent attended, in-laboratory overnight PSG (Nihon Kohden) with a pulse oximetry probe secured either to a finger or an ear lobe. PSG data were scored by a single experienced registered PSG technologist. Statistical analysis included demographic characteristics, continuous SpO2 measurement WD vs PSG root-mean-square error with Bland-Altman plot and linear regression associations. Predictive models for PSG oxygen desaturation index and AHI severity were built using logistic regression with probability cutoffs determined via receiver operating curve characteristics.

RESULTS

The 51 participants analyzed had a median age of 49 (range, 22-78) years; 66.7% were male, with median body mass index of 28.1 (range, 20.1-47.3) kg/m2 with a race/ethnicity distribution of 49.0% Caucasian, 25.5% Hispanic, 9.8% African American, 9.8% Asian, and 5.9% Middle Eastern. WD vs PSG continuous SpO2 measurement in percentage points demonstrated a bias of 0.91 (95% confidence interval, 0.38, 1.45), standard deviation of 2.37 (95% confidence interval, 2.36, 2.38), and root-mean-square error of 2.54 (95% confidence interval, 2.34, 2.73). WD area under the curve receiver operating curve characteristics for predicting PSG were 0.882 oxygen desaturation index > 15 events/h, 0.894 AHI > 30 events/h, 0.800 AHI > 15 events/h, and 0.803 AHI > 5 events/h. WD plus select sleep questionnaire areas under the curve for predicting PSG were 0.943 AHI > 30 events/h, 0.868 AHI > 15 events/h, and 0.863 AHI > 5 events/h.

CONCLUSIONS

The WD conducted reliable overnight continuous SpO2 monitoring with root-mean-square error < 3% vs PSG. Predictive models of PSG AHI based on WD measurements alone, or plus sleep questionnaires, demonstrated excellent to outstanding discrimination for obstructive sleep apnea identification and severity. Longitudinal WD use should be evaluated promptly based on the WD's potential to improve accessibility and accuracy of obstructive sleep apnea testing, as well as support treatment follow-up.

CITATION

Browne SH, Vaida F, Umlauf A, Kim J, DeYoung P, Owens RL. Performance of a commercial smart watch compared to polysomnography reference for overnight continuous oximetry measurement and sleep apnea evaluation. J Clin Sleep Med. 2024;20(9):1479-1488.

Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation.

OBJECTIVE

This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea.

METHODS

This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center.

RESULTS

A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively).

CONCLUSION

The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

A Narrative Review of the Association of Obstructive Sleep Apnea with Hypertension: How to Treat Both When They Coexist?

Hypertension (HT) is a worldwide public health issue and an essential risk factor for cardiovascular and cerebrovascular diseases. Obstructive sleep apnea (OSA) is a condition characterized by recurrent episodes of apnea and hypopnea as a consequence of partial or complete obstruction of the upper airways due to anatomic and/or functional disturbances. There is mounting evidence of a relationship between OSA and HT. In patients with OSA, HT is predominantly nocturnal and characterized by high diastolic blood pressure and usually by a nondipping pattern. Optimizing the blood pressure control is recommended in the current guidelines as the first treatment option in hypertensive patients with OSA. Continuous positive airway pressure (CPAP) therapy may reduce blood pressure, albeit only slightly as a stand-alone treatment. CPAP, as an add-on treatment to antihypertensive medication, appears to be an efficient treatment modality when both conditions coexist. This narrative review aims to summarize the current perspectives on the association of OSA with HT and the treatment options available for adults with OSA-related HT.

Relationships Between Cardinal Features of Obstructive Sleep Apnea and Blood Pressure: A Retrospective Study

BACKGROUND

Obstructive sleep apnea (OSA) is associated with hypertension; however, the associations between cardinal features of OSA, such as intermittent hypoxia (IH) and sleep fragmentation (SF), and blood pressure remain unclear. We performed this study to address this issue.

METHOD

We investigated 335 subjects with the polysomnography (PSG) tests. Data, including basic characteristics, PSG parameters, and blood pressure, were collected. We calculated p-values for linear trends of blood pressure across oxygen-desaturation index (ODI)/microarousal index (MAI) quartiles. Logistic regressions were used to determine the risk factors for abnormal blood pressure and to detect the multiplicative interaction between ODI and MAI with blood pressure.

RESULTS

After adjusting for multiple variables, compared with subjects with lower ODI quartiles, those with higher ODI quartiles had significant higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p for trend = 0.010 and 0.018, respectively). And compared with subjects with lower ODI quartiles, those with higher ODI quartiles were also more likely to have abnormal DBP and hypertension after adjusting for multiple variables. Similarly, compared with subjects with lower MAI quartiles, those with higher MAI quartiles had significant higher SBP and DBP, and were more likely to have abnormal DBP and hypertension. No significant multiplicative interactions between ODI and MAI with blood pressure were detected.

CONCLUSION

Subjects with more severe IH/SF had significant higher blood pressure and were more likely to have abnormal DBP and hypertension than those with less severe IH/SF. No interaction between IH and SF on the relationship with blood pressure was shown.

Nocturnal blood pressure and nocturnal blood pressure fluctuations: the effect of short-term CPAP therapy and their association with the severity of obstructive sleep apnea

STUDY OBJECTIVES

We determined the relationship of cardiovascular risk factors, cardiovascular diseases, nocturnal blood pressure (NBP), and NBP fluctuations (NBPFs) with the severity of obstructive sleep apnea (OSA). We also investigated the effect of short-term continuous positive airway pressure therapy on NBP parameters.

METHODS

This retrospective study included 548 patients from our cardiac clinic with suspected OSA. Patients underwent polysomnography and continuous NBP measurement using the pulse transit time. According to their apnea-hypopnea index (AHI), patients were subclassified as controls (AHI < 5 events/h), mild (AHI 5 to < 15 events/h), moderate (AHI 15 to < 30 events/h), and severe OSA (AHI ≥ 30 events/h); 294 patients received continuous positive airway pressure therapy.

RESULTS

Analysis of covariance showed that NBP and the frequency of NBPFs were the highest in severe followed by moderate and mild OSA (all P < .001). Multivariable regression analysis revealed a significant association of NBPFs with AHI, body mass index, systolic NBP, and lowest SpO₂. The severity of OSA is also associated with the frequency of obesity, hypertension, diabetes mellitus, atrial fibrillation, heart failure (all P < .001), and coronary artery disease (P = .035). Short-term continuous positive airway pressure decreased the frequency of NBPFs in all OSA groups and the systolic NBP in severe and moderate but not in mild OSA.

CONCLUSIONS

The severity of OSA is associated with an increase in NBP and NBPFs. Continuous positive airway pressure reduces NBP parameters already after the first night. In addition to BP, the diagnosis and therapy of NBPFs should be considered in patients with OSA.

CLINICAL TRIAL REGISTRATION

Registry: German Clinical Trials Register; Name: Nocturnal blood pressure and nocturnal blood pressure fluctuations associated with the severity of obstructive sleep apnea; URL: https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00024087; Identifier: DRKS00024087.

CITATION

Picard F, Panagiotidou P, Tammen A-B, et al. Nocturnal blood pressure and nocturnal blood pressure fluctuations: the effect of short-term CPAP therapy and their association with the severity of obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):361-371.

Association Between Arousals During Sleep and Hypertension Among Patients With Obstructive Sleep Apnea

Background

Sleep fragmentation induced by repetitive arousals is a hallmark of obstructive sleep apnea (OSA). Sleep fragmentation has been linked to hypertension in community‐based studies, but it is unclear if this association is manifest in OSA. We aimed to explore whether frequent arousals from sleep modify the relationship between OSA and prevalent hypertension.

Methods and Results

A total of 10 102 patients with OSA and 1614 primary snorers were included in the study. Hypertension was defined on either direct blood pressure measures or diagnosis by a physician. Spontaneous, respiratory, and movement arousals were derived by polysomnography. Logistic regression models were used to estimate the associations between arousals and prevalent hypertension in patients with OSA and primary snorers. For every 10‐unit increase of total arousal index, odds of hypertension significantly increased in both the total sample (odds ratio [OR], 1.08; 95% CI, 1.03–1.14; P=0.002) and patients with OSA (OR, 1.10; 95% CI, 1.04–1.16; P<0.001), but not in the primary snoring group. Total arousal index was significantly associated with systolic blood pressure and diastolic blood pressure in the total sample (β=0.05 and β=0.06; P<0.001) and in patients with (β=0.05 and β=0.06; P<0.01), but not in primary snorers. In addition, a greater influence of respiratory events with arousals than respiratory events without arousals on blood pressure in OSA was also noted. Results were independent of confounders, including apnea‐hypopnea index and nocturnal hypoxemia.

Conclusions

We conclude that repetitive arousals from sleep are independently associated with prevalent hypertension in patients with OSA.

Nocturnal blood pressure surge in seconds is a new determinant of left ventricular mass index

Nocturnal blood pressure (BP) surge in seconds (sec‐surge), which is characterized as acute transient BP elevation over several tens of seconds, could be a predictor of target organ damage. However, it is not clear that the severity of sec‐surge is different between sec‐surges induced by sleep apnea (SA) (apnea/hypopnea detected by polysomnography (PSG) or oxygen desaturation) and those induced by non‐SA factors (rapid eye movement, micro arousal, etc.), and sec‐surge variables associate with left ventricular hypertrophy (LVH) independently of conventional BP variables. The authors assessed these points with 41 patients (mean age 63.2±12.6 years, 29% female) who underwent full PSG, beat‐by‐beat (BbB) BP, and cuff‐oscillometric BP measurement during the night. All patients were included for the analysis comparing sec‐surge severity between inducing factors (SA and non‐SA factors). There were no significant differences in the number of sec‐surges/night between SA‐related sec‐surges and non‐SA‐related sec‐surges (19.5±26.0 vs. 16.4±29.8 events/night). There were also no significant differences in the peak of sec‐surges, defined as the maximum systolic BPs (SBPs) in each sec‐surge, between SA‐related sec‐surges and non‐SA‐related sec‐surges (148.2±18.5 vs. 149.3±19.2 mm Hg). Furthermore, as a result of multiple regression analysis (n = 18), the peak of sec‐surge was significantly and strongly associated with the left ventricular mass index (standardized β = 0.62, p = .02), compared with the mean nocturnal SBPs measured by oscillometric method (β = −0.04, p = .87). This study suggests that peak of sec‐surge could be a better predictor of LVH compared to parameters derived from regular nocturnal oscillometric SBP.

Associations between nocturnal continuous blood pressure fluctuations and the characteristics of oxygen desaturation in patients with obstructive sleep apnea: a pilot study

BACKGROUND

Patients with obstructive sleep apnea (OSA) frequently experience apnea-related oxygen desaturation events (ODE) accompanied by striking blood pressure (BP) fluctuations during sleep. We aimed to investigate the effects of characteristics of ODE on nocturnal BP fluctuations in OSA patients.

METHODS AND RESULTS

A total of 6199 ODE were obtained from 30 patients with who underwent overnight portable monitoring and beat-to-beat BP monitoring simultaneously. The associations between nocturnal BP parameters and the characteristics of ODE were studied. The mean value of systolic BP (SBP) monitored during ODE was higher than the non-hypoxia SBP value (122.0 ± 15.9 vs. 120.4 ± 15.1 mmHg, P = 0.001) and nighttime SBP value (122.0 ± 15.9 vs. 120.8 ± 15.0 mmHg, P = 0.002). SBP variability (SBPV) during ODE was higher than the values not during ODE (14.0 ± 2.8 vs. 13.2 ± 2.6 mmHg, P = 0.043) and nighttime SBPV (14.0 ± 2.8 vs. 12.9 ± 2.3 mmHg, P < 0.001). Hypoxia SBP index, defined as the percentage of SBP surge (△SBP) ≥10 mmHg to all △SBP during ODE, increased with greater respiratory event index (P = 0.01). Both the coefficient of variation for SBP values of an ODE (SBPV') and event-related SBP elevation (△SBP') increased with raised amplitude of ODE (P < 0.001 for SBPV' and P < 0.001 for △SBP'). Similar results were observed when the duration of events was analyzed (P < 0.001 for SBPV' and P < 0.001 for △SBP').

CONCLUSION

BP related to ODE may be the main component of increased BP during sleep in OSA patients. In addition to the frequency of respiratory events, the amplitude and duration of ODE may have a role in nocturnal BP fluctuations in OSA patients.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

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.

Automatic detection algorithm for establishing standard to identify "surge blood pressure"

Blood pressure (BP) variability is one of the important risk factors of cardiovascular disease (CVD). “Surge BP,” which represents short-term BP variability, is defined as pathological exaggerated BP increase capable of triggering cardiovascular events. Surge BP is effectively evaluated by our new BP monitoring device. To the best of our knowledge, we are the first to develop an algorithm for the automatic detection of surge BP from continuous “beat-by-beat” (BbB) BP measurements. It enables clinicians to save significant time identifying surge BP in big data from their patients’ continuous BbB BP measurements. A total of 94 subjects (74 males and 20 females) participated in our study to develop the surge BP detection algorithm, resulting in a total of 3272 surges collected from the study subjects. The surge BP detection algorithm is a simple classification model based on supervised learning which formulates shape of surge BP as detection rules. Surge BP identified with our algorithm was evaluated against surge BP manually labeled by experts with 5-fold cross validation. The recall and precision of the algorithm were 0.90 and 0.64, respectively. Processing time on each subject was 11.0 ± 4.7 s. Our algorithm is adequate for use in clinical practice and will be helpful in efforts to better understand this unique aspect of the onset of CVD.

Graphical abstract

Sleep Apnea Syndrome in an Elderly Population Admitted to a Geriatric Unit: Prevalence and Effect on Cognitive Function

Background

Sleep apnea leads to cognitive impairment in older patients, but its association with neurodegeneration remains controversial, and most studies do not distinguish between the more common obstructive form (OSAS) and the rarer central form (CSAS).

Objective

The purpose of this study was to assess the prevalence of the different forms of sleep apnea in a cohort of cognitively impaired elderly patients (>70 years) and to investigate their associations with cognitive deficit, weighted against known risk factors for neurodegeneration.

Methods

Overnight polygraphy was performed for 76 consecutive patients admitted to our geriatric unit. Their cognitive function was assessed using the Mini Mental-State Exam (MMSE), Mattis Dementia Rating Scale (MDRS) and Stroop test. Multivariable analyses were performed to determine associations between cognitive function and independent variables describing demographics, sleep apnea measures, and cardiovascular risk factors.

Results

The cohort comprised 58 women and 18 men aged a mean of 84 years (range, 73-96). Sleep apnea syndrome (SAS) was diagnosed in 48 patients (63%), of which 31 (41%) with OSAS and 17 (22%) with CSAS. Multivariable regression analysis revealed that MDRS was lower in patients with OSAS (β = -10.03, p = 0.018), that Stroop Colors and Words delays increased with AHI (β = 0.17, p = 0.030 and β = 0.31, p = 0.047) and that that Stroop Interference delay was higher in patients with CSAS (β = 24.45, p = 0.002).

Conclusion

Sleep apnea is thus highly prevalent in elderly patients with cognitive impairment. OSAS was associated with lower general cognitive function, while CSAS was only associated with increased Stroop Interference delays. Elderly patients with cognitive deficit could benefit from sleep apnea screening and treatment.

Key Points of the 2019 Japanese Society of Hypertension Guidelines for the Management of Hypertension

The new 2019 Japanese Society of Hypertension (JSH) guidelines for the management of hypertension are now available; these update the previous guidelines published in 2014. The primary objective of the guideline is to provide all healthcare professionals with a standard management strategy and appropriate antihypertensive treatments to prevent hypertension-related target organ damage and cardiovascular events. The major changes in the new guideline relate to the definition of normal blood pressure (BP) and target BP. The terms 'normal BP' and 'high normal BP' used in the JSH 2014 guidelines are replaced with terms 'high normal BP' and 'elevated BP,' respectively. There was no change to the office BP diagnostic threshold for hypertension (140/90 mmHg). Recommended target office and home BP values for patients with hypertension aged <75 years and/or high-risk patients are <130/80 mmHg and <125/75 mmHg, respectively. Corresponding targets for elderly patients with hypertension (age≥75 years) are 140/90 and 135/85 mmHg, respectively. The goal is that these changes will contribute to reducing cardiovascular events, especially stroke and heart failure, in Japan. The dissemination of the JSH 2019 guidelines and implementation of a home BP-based approach by all general practitioners in Japan might be facilitated by digital hypertension management using health information technology.

Validation of two watch-type wearable blood pressure monitors according to the ANSI/AAMI/ISO81060-2:2013 guidelines: Omron HEM-6410T-ZM and HEM-6410T-ZL

There is growing evidence of the clinical significance of daytime masked hypertension (MHT) and blood pressure (BP) variability (BPV). Recently, watch-type wearable devices for self-BP measurement have become available. Such devices might be promising tools to identify patients with daytime MHT or large BPV in their real-life conditions. The present study aimed to validate the accuracy of the Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL, which are automatic watch-type wearable devices for self-BP measurement, according to the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 guideline. Watches were held with the wrist at heart level. The mean differences between reference BPs and HEM-6410T-ZM readings were -0.9 ± 7.6/-1.1 ± 6.1 mm Hg for systolic BP (SBP)/diastolic BP (DBP) for criterion 1, and -0.9 ± 6.8/-1.1 ± 5.5 mm Hg for SBP/DBP for criterion 2. The mean differences between reference BPs and HEM-6410T-ZL readings were 2.4 ± 7.3/0.7 ± 7.0 mm Hg for SBP/DBP for criterion 1, and 2.4 ± 6.5/0.7 ± 6.5 mm Hg for SBP/DBP for criterion 2. The Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL both fulfilled both validation criteria 1 and 2 of the ANSI/AAMI/ISO 81060-2:2013 guidelines.