苅尾 七臣

INTRODUCTION: Stroke is the second-leading cause of death worldwide and the second-leading cause of disability-adjusted life-years. It is well known that hypertension is a significant risk factor for cardiovascular events, including stroke. AREAS COVERED: Recent interventional trials have demonstrated the superiority of intensive blood pressure (BP) control for prevention of cardiovascular events compared to standard BP control. Notably, in the Strategy of Blood Pressure Intervention in Elderly Hypertensive Patients (STEP) trial, intensive BP control showed superiority in the prevention of stroke events in elderly hypertensive patients. Novel medications such as angiotensin receptor-neprilysin inhibitors and sodium glucose cotransporter 2 inhibitors have the potential to suppress various CVD events including stroke. Non-pharmacological antihypertensive therapies such as renal denervation have demonstrated BP-lowering effects and may be useful for stroke prevention. Additionally, new methods and systems of BP monitoring including various kinds of nighttime BP measurement devices, wearable devices, and methods using information and communication technology can be used to assess the pathophysiology of BP variability as a risk factor and an event trigger of stroke incidence. EXPERT OPINION: Novel therapies and new technologies for BP evaluation strongly support the development of individualized anticipatory medicine, which should be useful for the prevention of stroke.

BACKGROUND: Inconsistencies between office and out-of-office blood pressure (BP) values (described as white-coat hypertension or masked hypertension) may be attributable in part to differences in the BP monitoring devices used. METHODS: We studied consistency in the classification of BP control (well-controlled BP vs. uncontrolled BP) among office, home, and ambulatory BPs by using a validated "all-in-one" BP monitoring device. In the nationwide, general practitioner-based multicenter HI-JAMP study, 2,322 hypertensive patients treated with antihypertensive drugs underwent office BP measurements and 24-h ambulatory BP monitoring (ABPM), consecutively followed by 5-day home BP monitoring (HBPM), for a total of seven BP measurement days. RESULTS: Using the thresholds of the JSH2019 and ESC2018 guidelines, the patients with consistent classification of well-controlled status in office (<140 mmHg) and home systolic BP (SBP) (<135 mmHg) (n=970) also tended to have well-controlled 24-h SBP (<130 mmHg) (n=808, 83.3%). The patients with consistent classification of uncontrolled status in office and home SBP (n=579) also tended to have uncontrolled 24-h SBP (n=444, 80.9%). Among the patients with inconsistent classifications of office and home BP control (n=803), 46.1% had inconsistent ABPM-vs.-HBPM out-of-office BP control status. When the 2017 ACC/AHA thresholds were applied as an alternative, the results were essentially the same. CONCLUSIONS: The combined assessment of office and home BP is useful in clinical practice. Especially for patients whose office BP classification and home BP classification conflict, the complementary clinical use of both HBPM and ABPM might be recommended.

BACKGROUND: Although day-by-day home blood pressure (BP) variability (BPV) has been associated with cardiovascular disease (CVD) risk, it remains unclear whether this association differs from season to season. The present study aimed to assess seasonal variation in day-by-day home BP variability and its association with CVD risk. METHODS: We analyzed the data from a nationwide, prospective observational study, the J-HOP study (Japan Morning Surge-Home Blood Pressure), in which 14 consecutive days of home BP monitoring were conducted. The values of SD (SDsystolic BP [SBP]), coefficient of variationSBP, and average real variabilitySBP of home SBP were used as indices of day-by-day home BPV. RESULTS: Among 4231 participants (mean age, 64.9±10.9 years, 46.7% male, 91.5% hypertensives), all 3 day-by-day home BPV indices were lower in summer than winter after adjusting for confounding factors. In winter, SDSBP, coefficient of variationSBP, and average real variabilitySBP were significantly associated with increased risk of CVD events (coronary artery disease, stroke, heart failure, and aortic dissection; adjusted hazard ratio [95%CI] per 1-SD of SDSBP, 1.26 [1.02-1.54]; coefficient of variationSBP, 1.24 [1.02-1.52]; average real variabilitySBP, 1.44 [1.17-1.77]). These relationships were also observed in the analysis of quartiles of BPV parameters (adjusted hazard ratio [95%CI] compared to the first quartile, fourth quartile of SDSBP 2.26 [1.06-4.85]; coefficient of variationSBP 2.96 [1.43-6.15]; average real variabilitySBP 2.73 [1.25-5.93]). In other seasons, however, there were no significant associations between day-by-day home BPV and CVD event risk. CONCLUSIONS: Our findings indicate that day-by-day home BPV measured in winter is more strongly associated with future CVD incidence than that measured in other seasons.

OBJECTIVE: The decision whether to measure night-time blood pressure (BP) is challenging as these values cannot be easily evaluated because of problems with measurement devices and related stress. Using the nationwide, practice-based Japan Morning Surge-Home BP Nocturnal BP study data, we developed a simple predictive score that physicians can use to diagnose nocturnal hypertension. METHODS: We divided 2765 outpatients (mean age 63 years; hypertensive patients 92%) with cardiovascular risks who underwent morning, evening, and night-time home BP (HBP) measurements (0200, 0300, and 0400 h) into a calibration group ( n  = 2212) and validation group ( n  = 553). We used logistic-regression models in the calibration group to identify the predictive score for nocturnal hypertension (night-time HBP ≥120/70 mmHg) and then evaluated the score's predictive ability in the validation group. RESULTS: In the logistic-regression model, male sex, increased BMI) (≥25 kg/m 2 ), diabetes, elevated urine-albumin creatinine ratio (UACR) (≥30 mg/g Cr), elevated office BP (≥140/90 mmHg) and home (average of morning and evening) BP (≥135/85 mmHg) had positive relationships with nocturnal hypertension. The predictive scores for nocturnal hypertension were 1 point (male, BMI, and UACR); 2 points (diabetes); 3 points (office BP ≥140/90 mmHg); 6 points (home BP ≥135/85 mmHg); total 14 points. Over 75% of the nocturnal hypertension cases in the validation group showed at least 10 points [AUC 0.691, 95% CI (0.647-0.735)]. We also developed a score for masked nocturnal hypertension, that is, nocturnal hypertension despite controlled daytime HBP. CONCLUSION: We developed a simple predictive score for nocturnal hypertension that can be used in clinical settings and for diagnoses.

BACKGROUND: Many cuffless blood pressure (BP) measuring devices are currently on the market claiming that they provide accurate BP measurements. These technologies have considerable potential to improve the awareness, treatment, and management of hypertension. However, recent guidelines by the European Society of Hypertension do not recommend cuffless devices for the diagnosis and management of hypertension. OBJECTIVE: This statement by the European Society of Hypertension Working Group on BP Monitoring and Cardiovascular Variability presents the types of cuffless BP technologies, issues in their validation, and recommendations for clinical practice. STATEMENTS: Cuffless BP monitors constitute a wide and heterogeneous group of novel technologies and devices with different intended uses. Cuffless BP devices have specific accuracy issues, which render the established validation protocols for cuff BP devices inadequate for their validation. In 2014, the Institute of Electrical and Electronics Engineers published a standard for the validation of cuffless BP devices, and the International Organization for Standardization is currently developing another standard. The validation of cuffless devices should address issues related to the need of individual cuff calibration, the stability of measurements post calibration, the ability to track BP changes, and the implementation of machine learning technology. Clinical field investigations may also be considered and issues regarding the clinical implementation of cuffless BP readings should be investigated. CONCLUSION: Cuffless BP devices have considerable potential for changing the diagnosis and management of hypertension. However, fundamental questions regarding their accuracy, performance, and implementation need to be carefully addressed before they can be recommended for clinical use.

BACKGROUND: Non-dipper and riser patterns of nocturnal blood pressure (BP) are risk factors for cardiovascular disease (CVD), including heart failure (HF). However, the risk associated with a disrupted nocturnal pattern of heart rate is not well known. OBJECTIVES: To investigate whether the nighttime heart rate is a risk factor for HF, alongside nighttime BP phenotype. METHODS: The practitioner-based, nationwide, prospective Japan Ambulatory Blood Pressure Monitoring Prospective (JAMP) study included patients with ≥ 1 CVD risk factor but without symptomatic CVD at baseline. All patients underwent 24-h ambulatory BP monitoring at baseline and were followed annually. Nocturnal heart rate dipping (%) was calculated as 100•[1 - nighttime/daytime heart rate]. RESULTS: During a mean 4.5 years' follow-up in 6,359 patients (mean age 68.6 years), there were 306 CVD events (119 stroke, 99 coronary artery disease, and 88 HF). A 10-beats/min increase in nighttime heart rate was significantly associated with a 36-47% increase in the risk of total CVD, stroke and HF events independently of office SBP and nighttime SBP (all p < 0.005). The CVD and HF risk associated with nocturnal heart rate dipping status was independent of office and 24-h systolic BP and nocturnal BP dipping status (p < 0.001). Performance of the final model for predicting HF including BP parameters was significantly improved by the addition of nocturnal heart rate dipping patterns (p = 0.038; C-statistic 0.852). CONCLUSION: Nighttime non-dipper and riser patterns of heart rate were associated with CVD especially HF, independently and additively of nocturnal BP dipping status, indicating the importance of antihypertensive strategies targeting nighttime hemodynamics. CLINICAL TRIAL REGISTRATION: URL: https://www.umin.ac.jp/ctr/ ; Unique identifier: UMIN000020377.

Pulse transit time (PTT), which refers to the travel time between two arterial sites within the same cardiac cycle, has been developed as a novel cuffless form of continuous blood pressure (BP) monitoring. The aim of this study was to investigate differences in BP parameters, including BP variability, between those assessed by beat-to-beat PTT-estimated BP (eBPBTB) and those assessed by intermittent PTT-estimated BP at fixed time intervals (eBPINT) in patients suspected of having sleep disordered breathing (SDB). In 330 patients with SDB (average age, 66.8 ± 11.9 years; 3% oxygen desaturation index [ODI], 21.0 ± 15.0/h) from 8 institutes, PTT-estimated BP was continuously recorded during the nighttime. The average systolic eBPBTB, maximum systolic and diastolic eBPBTB, standard deviation (SD) of systolic and diastolic eBPBTB, and coefficient variation (CV) of systolic and diastolic eBPBTB were higher than the respective values of eBPINT (all P < 0.05). Bland-Altman analysis showed a close agreement between eBPBTB and eBPINT in average systolic BP and SD and CV of systolic BP, while there were disagreements in both minimum and maximum values of eBPBTB and eBPINT in patients with high systolic BP (P < 0.05). Although systolic BP variability incrementally increased according to the tertiles of 3%ODI in both eBPBTB and eBPINT (all P < 0.05), there was no difference in this tendency between eBPBTB and eBPINT. In patients with suspected SDB, the difference between eBPBTB and eBPINT was minimal, and there were disagreements regarding both the minimum and maximum BP. However, there were agreements in regard to the index of BP variability between eBPBTB and eBPINT.

Accurate blood pressure (BP) measurement is necessary for the evaluation and treatment of hypertension to prevent the progression of subclinical vascular disease, including arterial stiffness. We investigated the associations between brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness, and each of office brachial systolic BP (SBP) with and without an observer present (attended or unattended office brachial SBP), attended or unattended office central SBP, and home brachial SBPs (specifically, the means of morning, evening, or morning-evening home brachial SBP) in patients being treated for hypertension. Measurements were performed among 70 adults (mean age, 67.0 ± 9.4 years; women, 51.4%) with a mean attended office brachial SBP of 127.6 ± 14.5 mmHg and mean baPWV of 16.3 ± 2.8 m/s. Univariate analysis showed that higher attended office brachial SBP, morning home brachial SBP, and morning-evening home brachial SBP were each statistically significantly associated with higher baPWV (r = 0.25, P = 0.04; r = 0.37, P = 0.002; and r = 0.32, P = 0.006, respectively). Multiple linear regression analysis with adjustments for traditional cardiovascular risk factors showed that only morning home brachial SBP was statistically significantly associated with baPWV [β = 0.06, 95% confidence interval (0.01-0.11), P = 0.02). In conclusion, higher morning home brachial SBP - but none of the office-measured SBP values - was associated with arterial stiffness.

Background The aim of this study was to investigate the association between night-to-night adherence to continuous positive airway pressure (CPAP) therapy and both home blood pressure (BP) level on the following day and seasonal variation in home BP in patients with obstructive sleep apnea. Methods and Results We analyzed 105 participants who had been diagnosed with obstructive sleep apnea (average apnea-hypopnea index, 49.7±18.4 per hour) and who were already receiving CPAP therapy. Home BP (twice every morning and evening) and CPAP adherence data were automatically transmitted to a server for 1 year. A mixed-effects model for repeated measures analysis was used to examine associations of night-to-night good CPAP adherence with day-to-day home BP within the same patient after adjusting for covariates. The average number of days in which patients achieved both CPAP adherence and morning or evening home BP measurement was 206.6±122.7 days (21 487 readings) and 191.2±126.3 days (20 170 readings), respectively. Good CPAP adherence (>4 hours per night of use) was achieved on the evening or morning before home BP measurements (86.8% and 86.9%, respectively). After adjustment for confounders, good CPAP adherence was negatively associated with morning home systolic BP (β, -0.663; P=0.004) and diastolic BP (β, -0.829; P<0.001). Morning home systolic BP in winter in the individuals with good CPAP adherence was significantly lower than that in individuals without such adherence (P<0.05). These associations were not found in evening home BP. Conclusions Good adherence to CPAP therapy was negatively associated with morning home BP on the following day in patients with obstructive sleep apnea. The association was remarkable in the winter season.

In diagnosis of treatment-resistant hypertension (TRH), guidelines recommend out-of-office blood pressure (BP) measurements, ambulatory BP monitoring (ABPM) and home BP monitoring (HBPM). Although evidence of an association between ABPM-evaluated TRH and cardiovascular disease (CVD) prognosis has accumulated, data are sparse regarding HBPM-evaluated TRH. We investigated this issue using data from the nationwide practice-based J-HOP (Japan Morning-Surge Home BP) study, which recruited 4,261 outpatients (mean age 64.9 years; 46.8% men; 91.5% hypertensives) who underwent morning and evening HBPM for 14 days. During 6.2 ± 3.8 years (26,418 person-years) follow-up, 270 total CVDs (stroke, coronary artery disease, aortic dissection, and heart failure) occurred. The adjusted hazard ratio (HR) (95% CIs) of uncontrolled TRH, i.e., uncontrolled BP using 3 classes of medications including diuretics or ≥4 classes of medications, for total CVD risk compared to controlled BP using <3 classes were 2.02 (1.38-2.94) and 1.81 (1.23-2.65) in home BP of 135/85 mmHg and 130/80 mmHg, respectively. Additionally, patients with TRH defined by guidelines, i.e., uncontrolled BP using 3 classes of medications including diuretics or controlled/uncontrolled BP using ≥4 classes of medications, also had higher total CVD risk compared to non-TRH under all home BP criteria. Moreover, in patients with uncontrolled apparent-TRH, i.e., TRH defined by office BP, uncontrolled home BP (≥135/85 mmHg) was still associated with atherosclerotic CVD (CVDs except heart failure) risk (adjusted HR [95% CI], 2.38 [1.09-5.19]). This is the first study to demonstrate an independent association between TRH evaluated by HBPM and CVD outcomes.

BACKGROUND: The causal relationship between hyperuricemia and cardiovascular diseases is still unknown. We hypothesized that hyperuricemic patients after percutaneous coronary intervention (PCI) had a higher risk of major adverse cardiovascular events (MACE). METHODS: This was a large-scale multicenter cohort study. We enrolled patients with chronic coronary syndrome (CCS) after PCI between April 2013 and March 2019 using the database from the Clinical Deep Data Accumulation System (CLIDAS), and compared the incidence of MACE, defined as a composite of cardiovascular death, myocardial infarction, and hospitalization for heart failure, between hyperuricemia and non-hyperuricemia groups. RESULTS: In total, 9,936 patients underwent PCI during the study period. Of these, 5,138 patients with CCS after PCI were divided into two group (1,724 and 3,414 in the hyperuricemia and non-hyperuricemia groups, respectively). The hyperuricemia group had a higher prevalence of hypertension, atrial fibrillation, history of previous hospitalization for heart failure, and baseline creatinine, and a lower prevalence of diabetes than the non-hyperuricemia group, but the proportion of men and age were similar between the two groups. The incidence of MACE in the hyperuricemia group was significantly higher than that in the non-hyperuricemia group (13.1 vs. 6.4%, log-rank P < 0.001). Multivariable Cox regression analyses revealed that hyperuricemia was significantly associated with increased MACE [hazard ratio (HR), 1.52; 95% confidential interval (CI), 1.23-1.86] after multiple adjustments for age, sex, body mass index, estimated glomerular filtration rate, left main disease or three-vessel disease, hypertension, diabetes mellitus, dyslipidemia, history of myocardial infarction, and history of hospitalization for heart failure. Moreover, hyperuricemia was independently associated with increased hospitalization for heart failure (HR, 2.19; 95% CI, 1.69-2.83), but not cardiovascular death or myocardial infarction after multiple adjustments. Sensitive analyses by sex and diuretic use, B-type natriuretic peptide level, and left ventricular ejection fraction showed similar results. CONCLUSION: CLIDAS revealed that hyperuricemia was associated with increased MACE in patients with CCS after PCI. Further clinical trials are needed whether treating hyperuricemia could reduce cardiovascular events or not.

Background Growth differentiation factor-15 (GDF-15) has emerged as a novel biomarker to predict all-cause death in community-dwelling individuals and patients with cardiovascular disease. We evaluated the prognostic value of GDF-15 in outpatients with cardiovascular risk factors. Methods and Results GDF-15 levels were measured in 3562 outpatients with cardiovascular risk factors in the J-HOP (Japan Morning Surge-Home Blood Pressure) study, a nationwide prospective study. Participants were stratified according to tertiles of GDF-15 and followed up for all-cause death and cardiovascular disease. During a mean follow-up period of 6.6 years, there were 155 all-cause deaths, 81 stroke events including cerebral infarction and intracranial hemorrhage, and 141 cardiac events including cardiac artery disease and heart failure. Patients with higher GDF-15 levels were associated with risks of all-cause death and stroke events (except for cardiac events) after adjustment for traditional risk factors and other prognostic biomarkers (NT-proBNP [N-terminal pro-B-type natriuretic peptide], high-sensitivity troponin T; all-cause death, hazard ratio, 2.38; 95% CI, 1.26-4.48; P=0.007; stroke events, hazard ratio, 2.93; 95% CI, 1.31-6.56, P=0.009; compared with the lowest tertile). Furthermore, incorporating GDF-15 to the predictive models for all-cause death improved discrimination and reclassification significantly. For stroke events, GDF-15 showed similar diagnostic accuracy to NT-proBNP and high-sensitivity troponin T. Conclusions In Japanese outpatients with cardiovascular risk factors, GDF-15 improves risk stratification for all-cause death when compared with NT-proBNP and high-sensitivity troponin T. GDF-15 was associated with increased risks of stroke events beyond conventional risk factors and other prognostic markers; however, the predictive ability for stroke events was equivalent to NT-proBNP and high-sensitivity troponin T. Registration URL: http://www.umin.ac.jp/ctr.; Unique identifier: UMIN000000894.

Little is known about the relationship of the difference between morning and evening systolic blood pressure (BP) (MEdif) in home BP with cardiovascular disease (CVD) incidence. To assess this relationship, we used data from the nationwide practice-based J-HOP (Japan Morning Surge-Home BP) study, which recruited 4258 cardiovascular risk participants (mean age 64.9 years; 46.8% men; 79.2% using antihypertensive medications) who underwent morning and evening home BP monitoring using a validated, automated device for 14 consecutive days. During a mean ± SD follow-up of 6.2 ± 3.8 years (26,295 person-years), 269 CVD events occurred. Adjusted Cox models suggested that higher MEdif (≥20 mmHg) was associated with higher CVD risks than was medium MEdif (0-20 mmHg) independent of the average morning and evening (MEave) home systolic BP (SBP) (adjusted hazard ratio [HR]: 1.40; 95% confidence interval [CI] 1.02-1.91). We also divided participants into four BP phenotype groups as follows: "both non-elevated" (MEdif < 20 mmHg and MEave SBP < 135 mmHg), "elevated-MEdif" (MEdif ≥ 20 mmHg and MEave SBP < 135 mmHg), "elevated-MEave" (MEdif < 20 mmHg and MEave SBP ≥ 135 mmHg), and "both elevated" (MEdif ≥ 20 mmHg and MEave SBP ≥ 135 mmHg). The cumulative incidence of CVD events was higher in patients with the "elevated-MEdif," "elevated-MEave," and "both elevated" phenotypes than in those with the "both non-elevated" phenotype. After adjusting for covariates, the "both elevated" phenotype was associated with higher CVD risk than the "both non-elevated" phenotype (adjusted HR: 1.64; 95% CI: 1.09-2.46). This is the first study demonstrating a direct correlation between CVD outcomes and the difference between morning and evening home SBP.

[Figure: see text].

Blood pressure (BP) exhibits seasonal variation, with an elevation of daytime BP in winter and an elevation of nighttime BP in summer. The wintertime elevation of daytime BP is largely attributable to cold temperatures. The summertime elevation of nighttime BP is not due mainly to temperature; rather, it is considered to be related to physical discomfort and poor sleep quality due to the summer weather. The winter elevation of daytime BP is likely to be associated with the increased incidence of cardiovascular disease (CVD) events in winter compared to other seasons. The suppression of excess seasonal BP changes, especially the wintertime elevation of daytime BP and the summertime elevation of nighttime BP, would contribute to the prevention of CVD events. Herein, we review the literature on seasonal variations in BP, and we recommend the following measures for suppressing excess seasonal BP changes as part of a regimen to manage hypertension: (1) out-of-office BP monitoring, especially home BP measurements, throughout the year to evaluate seasonal variations in BP; (2) the early titration and tapering of antihypertensive medications before winter and summer; (3) the optimization of environmental factors such as room temperature and housing conditions; and (4) the use of information and communication technology-based medicine to evaluate seasonal variations in BP and provide early therapeutic intervention. Seasonal BP variations are an important treatment target for the prevention of CVD through the management of hypertension, and further research is necessary to clarify these variations.

BACKGROUND: The incidence of cardiovascular disease (CVD) increases during winter. The risk that elevated home blood pressure (BP) poses for CVD events that occur in each of 4 seasons is unclear. We conducted a post hoc analysis using the dataset from a nationwide cohort, the Japan Morning Surge-Home Blood Pressure (J-HOP) study, to assess the association between home BP and winter-onset CVD events. METHODS: J-HOP participants who had cardiovascular risks conducted morning and evening home BP measurements for a 14-day period and were followed-up for the occurrence of CVD events. RESULTS: We analyzed 4,258 participants (mean age 64.9 years; 47% male; 92% hypertensives) who were followed-up for an average of 6.2 ± 3.8 years (26,295 person-years). We divided the total of 269 CVD events (10.2/1,000 person-years) by the season of onset as follows: 82 in the winter and 187 in the other seasons (spring, summer, and autumn). In the Cox models adjusted for covariates and the season when home BPs were measured at baseline, morning home systolic BP (SBP) was associated with both winter-onset and other season-onset CVD events: hazard ratio (HR) for winter 1.22, 95% confidence interval (CI) 1.06-1.42 per 10 mm Hg; HR for other seasons 1.11, 95% CI 1.00-1.23. Evening home SBP was associated with the other season-onset CVD events (HR 1.20, 95% CI 1.08-1.33 per 10 mm Hg), but not with the winter-onset CVD events. CONCLUSIONS: Our findings indicate that compared with evening home BP, morning home BP might be a superior predictor of winter-onset CVD events.

BACKGROUND: Little is known about seasonal variation in nighttime blood pressure (BP) measured by a home device. In this cross-sectional study, we sought to assess seasonal variation in nighttime home BP using data from the nationwide, practice-based Japan Morning Surge-Home BP (J-HOP) Nocturnal BP study. METHODS: In this study, 2,544 outpatients (mean age 63 years; hypertensives 92%) with cardiovascular risks underwent morning, evening, and nighttime home BP measurements (measured at 2:00, 3:00, and 4:00 am) using validated, automatic, and oscillometric home BP devices. RESULTS: Our analysis showed that nighttime home systolic BP (SBP) was higher in summer than in other seasons (summer, 123.3 ± 14.6 mmHg vs. spring, 120.7 ± 14.8 mmHg; autumn, 121.1 ± 14.8 mmHg; winter, 119.3 ± 14.0 mmHg; all P<0.05). Moreover, we assessed seasonal variation in the prevalence of elevated nighttime home SBP (≥120 mmHg) in patients with non-elevated daytime home SBP (average of morning and evening home SBP <135 mmHg; n = 1,565), i.e., masked nocturnal hypertension, which was highest in summer (summer, 45.6% vs. spring, 27.2%; autumn, 28.8%; winter, 24.9%; all P<0.05). Even in intensively controlled morning home SBP (<125 mmHg), the prevalence of masked nocturnal hypertension was higher in summer (summer, 27.4% vs. spring, 14.2%; autumn, 8.9%; winter, 9.0%; all P<0.05). The urine albumin-creatinine ratio in patients with masked nocturnal hypertension tended to be higher than that in patients with non-elevated both daytime and nighttime SBP throughout each season. CONCLUSIONS: The prevalence of masked nocturnal hypertension was higher in summer than other seasons and the difference proved to be clinically meaningful.