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Featured researches published by Tomohiro Hanazawa.


American Journal of Hypertension | 2008

Association of microalbuminuria with brachial-ankle pulse wave velocity: the Ohasama study.

Tomofumi Ishikawa; Junichiro Hashimoto; Rieko H. Morito; Tomohiro Hanazawa; Tomoyuki Aikawa; Azusa Hara; Yoriko Shintani; Hirohito Metoki; Ryusuke Inoue; Kei Asayama; Masahiro Kikuya; Takayoshi Ohkubo; Kazuhito Totsune; Haruhisa Hoshi; Hiroshi Satoh; Yutaka Imai

BACKGROUND Microalbuminuria is recognized as a marker of generalized vascular dysfunction. However, the associations between microalbuminuria and pulse wave velocity (PWV), carotid intima-media thickness (IMT), and ambulatory blood pressure (ABP), respectively, have not been investigated. METHODS Brachial-ankle PWV (baPWV), IMT, and ABP were determined in 328 individuals (mean age, 65.7 +/- 6.4 years) from the general population of Ohasama, a rural Japanese community. The participants were assigned to groups with microalbuminuria and with normoalbuminuria, and their characteristics were compared. We also examined the association between microalbuminuria and baPWV, IMT, and ABP, respectively, using multivariate analyses. RESULTS Seventy-nine participants (24%) with microalbuminuria had significantly higher baPWV (P < 0.001) and 24-h systolic BP (SBP) (P = 0.006) than those with normoalbuminuria, although 24-h pulse pressure and mean IMT did not significantly differ between the groups. Multiple logistic regression analyses showed that baPWV, but not 24-h ABP, was independently associated with microalbuminuria (P = 0.002) when adjusted for various confounding factors. After further adjustment for 24-h SBP, the association between baPWV and microalbuminuria remained significant (P = 0.012). The trend was significant even when daytime or nighttime SBP was used instead of 24-hour SBP in this model. CONCLUSIONS Microalbuminuria appears to be associated with baPWV more closely than with IMT and ABP, and its association with baPWV is independent of ABP and other cardiovascular risk factors.


Journal of the American Heart Association | 2016

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

Kei Asayama; Takayoshi Ohkubo; Tomohiro Hanazawa; Daisuke Watabe; Miki Hosaka; Michihiro Satoh; Daisaku Yasui; Jan A. Staessen; Yutaka Imai

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.


Hypertension Research | 2017

Seasonal variation in self-measured home blood pressure among patients on antihypertensive medications: HOMED-BP study

Tomohiro Hanazawa; Kei Asayama; Daisuke Watabe; Miki Hosaka; Michihiro Satoh; Daisaku Yasui; Taku Obara; Ryusuke Inoue; Hirohito Metoki; Masahiro Kikuya; Yutaka Imai; Takayoshi Ohkubo

Seasonal variation of blood pressure (BP) has been reported in small populations or by BP levels captured at only a few points in a year, for example, summer and winter. We aimed to investigate the multiyear seasonal variation in self-measured home BP among hypertensive patients receiving antihypertensive medications. We selected 1649 eligible patients receiving antihypertensive drug treatment, and weekly averaged home BPs were analyzed throughout the follow-up period. Systolic and diastolic home BPs were fitted with the cosine function: ‘Variation+Other Effects+Intercept’, in which the ‘Variation’ was expressed by a cosine curve with three parameters representing: (1) maximum–minimum difference of home BP in one cycle of the cosine curve; (2) time required for one cycle of the cosine curve for home BP variation; and (3) time at which home BP reached the maximum point. Maximum–minimum differences in home BP were 6.7/2.9 mm Hg, and the highest home BPs were observed in mid-to-late January. In the multivariable-adjusted model, a large maximum–minimum difference in home BP was associated with lower body mass index and older age, and larger differences were observed in men compared with women. Summer–winter difference in home BP was essentially similar every year, though it was marginally reduced by 0.14/0.04 mm Hg per year, under long-term antihypertensive treatment. Records of daily home BP measurements enable us to capture long-term factors such as seasonal variation. Home BP should therefore be carefully monitored, particularly in patients with increased BP in winter, to mitigate cardiovascular risk.


Clinical and Experimental Hypertension | 2011

Low-Dose and Very Low-Dose Spironolactone in Combination Therapy for Essential Hypertension: Evaluation by Self-Measurement of Blood Pressure at Home

Tomohiro Hanazawa; Taku Obara; Kei Ogasawara; Takahiro Shinki; Sakiko Katada; Ryusuke Inoue; Hirohito Metoki; Kei Asayama; Masahiro Kikuya; Takayoshi Ohkubo; Nariyasu Mano; Yutaka Imai

Low-dose (25 mg) or very low-dose (12.5 mg) spironolactone were added among 86 uncontrolled hypertensive patients who were undergoing monotherapy with calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin AT1-receptor blockers (ARBs). Morning home systolic/diastolic blood pressure (BP) reduction was similar among the CCB (n = 30, −8.2/−2.6 mmHg), ACEI (n = 22, −13.0/−4.7 mmHg), and ARB (n = 34, −11.5/−5.1 mmHg) groups. An increase in serum potassium correlated positively with the decline in morning systolic BP. Even very low-dose (12.5 mg) spironolactone is clinically effective, although serum potassium should be carefully monitored.


Clinical and Experimental Hypertension | 2011

Individual Assessment of Inherent Arterial Stiffness Using Nomogram and Pulse Wave Velocity Index: The Ohasama Study

Rieko Hatanaka; Taku Obara; Daisuke Watabe; Atsushi Kimura; Tomohiro Hanazawa; Hiromi Ohba; Tomofumi Ishikawa; Tomoyuki Aikawa; Azusa Hara; Hirohito Metoki; Kei Asayama; Masahiro Kikuya; Takayoshi Ohkubo; Kazuhito Totsune; Yutaka Imai

Abstract We measured the brachial-ankle pulse wave velocity (baPWV) in 491 normotensives and determined the “PWV index” (measured baPWV–theoretical baPWV) in 491 normotensives and 83 controlled hypertensives. Linear regression analysis revealed that the theoretical baPWV (cm/sec) was 0.21 × age2 (years2)−13.73 × age (years) + 0.05 × mean arterial pressure2 (mmHg2) + 3.95 × heart rate (bpm) + 36.49 × gender (1 male; 0 female) + 733 (R2 = 0.53). The calculated PWV index was significantly higher in 13 smokers than 70 nonsmokers among controlled hypertensives. The calculated PWV index might provide more precise information about inherent arterial stiffness.


Journal of the American Heart Association | 2018

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

Tomohiro Hanazawa; Kei Asayama; Daisuke Watabe; Ayumi Tanabe; Michihiro Satoh; Ryusuke Inoue; Azusa Hara; Taku Obara; Masahiro Kikuya; Kyoko Nomura; Hirohito Metoki; Yutaka Imai; Takayoshi Ohkubo

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.


Hypertension Research | 2018

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

Daisuke Watabe; Kei Asayama; Tomohiro Hanazawa; Miki Hosaka; Michihiro Satoh; Daisaku Yasui; Taku Obara; Ryusuke Inoue; Hirohito Metoki; Masahiro Kikuya; Yutaka Imai; Takayoshi Ohkubo

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.


Clinical and Experimental Hypertension | 2018

Effect of amlodipine, efonidipine, and trichlormethiazide on home blood pressure and upper-normal microalbuminuria assessed by casual spot urine test in essential hypertensive patients

Miki Hosaka; Ryusuke Inoue; Michihiro Satoh; Daisuke Watabe; Tomohiro Hanazawa; Takayoshi Ohkubo; Kei Asayama; Taku Obara; Yutaka Imai

ABSTRACT The aim of this study was to assess the effects of irbesartan alone and combined with amlodipine, efonidipine, or trichlormethiazide on blood pressure (BP) and urinary albumin (UA) excretion in hypertensive patients with microalbuminuria (30≤UA/creatinine (Cr) ratio [UACR] <300 mg/g Cr) and upper-normal microalbuminuria (10≤UACR<30 mg/g Cr). This randomized controlled trial enrolled 175 newly diagnosed and untreated hypertensive patients (home systolic blood pressure [SBP]≥135 mmHg; 10≤UACR<300 mg/g Cr of casual spot urine at the first visit to clinic). All patients were treated with irbesartan (week 0). Patients who failed to achieve home SBP ≤125 mmHg on 8-week irbesartan monotherapy (nonresponders, n = 115) were randomized into three additional drug treatment groups: trichlormethiazide (n = 42), efonidipine (n = 39), or amlodipine (n = 34). Irbesartan monotherapy decreased home SBP and first morning urine samples (morning UACR) for 8 weeks (p < 0.0001). At 8 weeks after randomization, all three additional drugs decreased home SBP (p < 0.0002) and trichlormethiazide significantly decreased morning UACR (p = 0.03). Amlodipine decreased morning UACR in patients with microalbuminuria based on casual spot urine samples (p = 0.048). However, multivariate analysis showed that only higher home SBP and UACR at week 8, but not any additional treatments, were significantly associated with UACR reduction between week 8 and week 16. In conclusion, crucial points of the effects of combination therapy on UACR were basal UACR and SBP levels. The effect of trichlormethiazide or amlodipine treatment in combination with irbesartan treatment on microalbuminuria needs to be reexamined based on a larger sample size after considering basal UACR and SBP levels.


Hypertension Research | 2017

Response to Yatabe et al.

Tomohiro Hanazawa; Kei Asayama; Yutaka Imai; Takayoshi Ohkubo

We thank Dr Yatabe et al.1 for their interest in our subanalysis of the Hypertension Objective Treatment based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study regarding seasonal variations in home blood pressure.2 As they indicated,1 the lack of data on room temperature, which would affect home blood pressure on each occasion, was a limitation of the HOMED-BP study. Because the addresses of study patients were not collected, we instead used regional information from study centers for the analysis of summer–winter differences in the home blood pressure, that is, northern or southern part of Japan.2 The incorporation of an automated thermometer (a temperature data logger) into the blood pressure measurement device1 seems be an innovative approach for home monitoring, as few studies investigating seasonal variation have focused on room temperature.3 However, some studies have evaluated the association between outdoor temperature and blood pressure,4, 5 and our report2 regarding overall trends in seasonal variations in blood pressure supports their findings that the outdoor temperature is highly correlated with the blood pressure in a population.4, 5 Surprisingly, just as in HOMED-BP, a slight shift in the timing of seasonal variations in blood pressure to a few weeks earlier than the nadir and peak of outdoor temperature was also observed among the participants in Aizumisato town in which the room temperature instead of the outdoor temperature was assessed.1


Hypertension Research | 2017

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

Ayumi Tanabe; Kei Asayama; Tomohiro Hanazawa; Daisuke Watabe; Kyoko Nomura; Tomonori Okamura; Takayoshi Ohkubo; Yutaka Imai

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.

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