Hypertension Research

Original Articles

Clinical studies

Stress Profile in Essential Hypertension

Rajeev M. KAUSHIK, Sukhdev K. MAHAJAN, Vemreddi RAJESH, Reshma KAUSHIK

2004 年 27 巻 9 号 p. 619-624
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.619

ジャーナルフリー

抄録を表示する抄録を非表示にする

This study was undertaken to test the hypothesis that basal sympathetic activity and sympathetic reactivity to stress are increased in patients with essential hypertension. One hundred and fifteen randomly selected patients with essential hypertension and an equal number of age- and sex-matched normal controls were included in this study. Various parameters, viz., heart rate, respiratory rate, blood pressure, peripheral skin temperature, electromyographic activity of the frontalis muscle, skin conductance (measured by electrodermography), and blood pressure, were measured in the resting state in both groups. These parameters were then measured during the performance of various stressful activities, such as mental arithmetical calculations, thinking of unpleasant thoughts, staring at a fixed point, catching of a dropped object, and reading aloud for 1 min each, and again over a 1-min quiet period following each stressful activity. Changes in various parameters in the two groups were analyzed and compared. Baseline heart rate, respiratory rate, electromyographic activity and peripheral skin temperature were higher—while skin conductance was lower—in the hypertensive group than in the control group. The increases in systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate, electromyographic activity, and peripheral skin temperature in response to stress were greater in hypertensive patients than in controls, while skin conductance showed a higher elevation in controls than in hypertensive patients. In conclusion, sympathetic nervous system activity is increased in patients with essential hypertension. The reduced skin conductance and high peripheral skin temperature in these patients may be due to a possible dermal neurovascular dysfunction. (Hypertens Res 2004; 27: 619-624)

抄録全体を表示

PDF形式でダウンロード (61K)
Arterial Stiffening as a Possible Risk Factor for Both Atherosclerosis and Diastolic Heart Failure

Minoru YAMBE, Hirofumi TOMIYAMA, Yoji HIRAYAMA, Zaydun GULNIZA, Yoshif ...

2004 年 27 巻 9 号 p. 625-631
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.625

ジャーナルフリー

抄録を表示する抄録を非表示にする

While arterial stiffness is known to be related to atherosclerosis, the association between arterial stiffness and cardiac systolic and diastolic function in hypertension has not been fully evaluated. The present study was conducted to simultaneously evaluate the relationship of brachial-ankle pulse wave velocity (PWV) to parameters reflecting atherosclerosis and to those reflecting the risk of congestive heart failure in patients with hypertension. In 147 patients with hypertension, the left ventricular ejection fraction, the ratio of the peak velocity of early rapid filling and the peak velocity of atrial filling (E/A ratio), and left ventricular mass index were obtained from echocardiographs, the intima-media thickness of the common carotid artery was obtained by ultrasonography, the plasma B-type natriuretic peptide (BNP) level was measured by radioimmunoassay, and the brachial-ankle PWV was measured by the volume rendering method. Brachial-ankle PWV correlated positively with the intima-media thickness of the carotid artery, E/A ratio and BNP. Multiple linear regression analysis demonstrated that the relationship between the brachial-ankle PWV and the E/A ratio was significantly independent from other clinical variables. The receiver operator characteristic curve demonstrated that a brachial-ankle PWV of 1,600 cm/s was useful to discriminate mild cardiac diastolic dysfunction (E/A ratio of ≤0.75) (sensitivity=78% and specificity=58%). The present study demonstrated that increased brachial-ankle PWV relates not only to the parameters reflecting atherosclerosis but also to those reflecting cardiac diastolic dysfunction. Therefore, increased arterial stiffness is a possible simultaneous risk for atherosclerotic cardiovascular disease and diastolic heart failure in patients with hypertension. (Hypertens Res 2004; 27: 625-631)

抄録全体を表示

PDF形式でダウンロード (46K)
Home Blood Pressure Is a Better Predictor of Carotid Atherosclerosis than Office Blood Pressure in Community-Dwelling Subjects

Rieko TACHIBANA, Yasuharu TABARA, Ikuko KONDO, Tetsuro MIKI, Katsuhiko ...

2004 年 27 巻 9 号 p. 633-639
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.633

ジャーナルフリー

抄録を表示する抄録を非表示にする

An increase in the thickness of the intima-media (IMT) of the carotid artery is associated with an increased risk of cardiovascular morbidity and mortality. Hypertension is one of the underlying mechanisms for the progression of carotid atherosclerosis. However, office blood pressure (BP) has been shown to have only a weak association with carotid IMT. Since self-measured home BP has less variation than office BP, home BP could be a better predictor of carotid atherosclerosis. To explore this hypothesis, we compared the relationships between carotid IMT and office BP or home BP in a community-dwelling population. One-hundred and one community residents, aged 50 years or older and not taking any medication, were enrolled in this study. Morning home BP was measured according to the guidelines of the Japanese Society of Hypertension. The results were recorded for 2 weeks and averaged. Carotid atherosclerosis was defined as IMT ≥0.80 mm, which corresponds to the first quartile. Home systolic BP showed a more significant association with carotid IMT (r =0.422, p <0.0001) than with office systolic BP (r =0.021, p =0.027). Logistic regression analysis for the presence of carotid atherosclerosis further showed that the relative risk of hypertension defined using home BP (≥135/85 mmHg) was 6.3 (95% confidence interval [CI]: 2.0 to 19.6), while that using office BP was 1.5 (95% CI: 0.5 to 4.2). These results suggest that home BP is a better predictor of the development of carotid atherosclerosis than office BP. (Hypertens Res 2004; 27: 633-639)

抄録全体を表示

PDF形式でダウンロード (50K)
Relation of Pulsatility of Brachial Artery Pressure to Resistant Hypertension

Yuji YOSHITOMI, Chieko NAGAKURA, Atsuyoshi MIYAUCHI

2004 年 27 巻 9 号 p. 641-646
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.641

ジャーナルフリー

抄録を表示する抄録を非表示にする

Few studies have examined predictors of resistant hypertension. The aim of this study was to observe the relationship between resistant hypertension and the pulsatility of the brachial artery pressure, which is characterized as pulse pressure/diastolic pressure (PP/DP) and is a simple index of aortic input impedance. We obtained home blood pressure (BP) measurements for 102 patients aged 40-75 years with either office systolic BP (SBP) ≥140 mmHg or office diastolic BP (DBP) ≥90 mmHg. Patients were given a single antihypertensive agent or left untreated during the 2-week baseline period. Thereafter, patients were treated with 1 to 3 antihypertensive drugs for 1 year with a goal of achieving a home BP of less than 135/85 mmHg. At follow-up, 72 patients were taking a single drug with good BP control, 21 were taking two drugs with good BP control, and 9 were taking three drugs with poor BP control. Although office SBP at baseline was similar among the three groups, home morning and evening SBP at baseline in the single drug group were lower than those of the two- or three-drug groups (p <0.01). Although office PP/DP at baseline did not differ among the three groups, home morning and evening PP/DP at baseline were highest in the three-drug group (p <0.01). In multivariate analysis, only mean home PP/DP at baseline was correlated with BP control. There is a correlation between the pulsatility of the brachial artery pressure and the degree of BP control. (Hypertens Res 2004; 27: 641-646)

抄録全体を表示

PDF形式でダウンロード (33K)
Ambulatory Blood Pressure Level Rather than Dipper/Nondipper Status Predicts Vascular Events in Type 2 Diabetic Subjects

Shigeru NAKANO, Tomohiko ITO, Keisuke FURUYA, Shin-ichi TSUDA, Kazunor ...

2004 年 27 巻 9 号 p. 647-656
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.647

ジャーナルフリー

抄録を表示する抄録を非表示にする

To clarify which parameter, diurnal pattern of blood pressure (BP) or level of BP variability, has the stronger predictive value for fatal and nonfatal vascular events, vital status after a mean (±SD) follow-up period of 86±46 months was determined in 392 type 2 diabetic subjects without any history of vascular disease, in whom the 24-h BP profile had been monitored between 1988 and 1998. After the exclusion of 28 subjects who died during the follow-up period of causes unrelated to diabetes, 364 subjects were recruited for further analysis. A total of 147 first events, including 50 fatal vascular events and 97 nonfatal vascular events, were recorded during the follow-up period. The rates of various vascular events increased with both reduced nocturnal falls in systolic BP (SBP) and levels of all ambulatory BP parameters. The ambulatory BP parameter showing the largest area under the receiver operating characteristic curve (ROC_AUC) for fatal events was the mean 24-h pulse pressure (PP), and that for nonfatal events was the mean nighttime SBP; both exceeded the respective values of nocturnal fall in SBP. Furthermore, when dipper and nondipper diabetic subjects were divided into subgroups based on the 24-h PP (54.3 mmHg) and the nighttime SBP (116.5 mmHg) cut-off points derived from the ROC analyses, Kaplan-Meier plots showed that the diabetic subgroups with high ambulatory BP levels had worse outcomes, independent of dipper/nondipper status. Finally, these parameters were applied to the Cox model with the values of nocturnal fall in SBP and other confounding factors, and results showed that mean 24-h PP and mean nighttime SBP predicted fatal and nonfatal vascular events, respectively, more strongly than nocturnal fall in SBP in type 2 diabetic subjects. These findings therefore suggest that ambulatory BP levels in type 2 diabetic subjects have a higher predictive value for organ damage and death compared with diurnal BP patterns or dipper/nondipper status. (Hypertens Res 2004; 27: 647-656)

抄録全体を表示

PDF形式でダウンロード (272K)
Valsartan in Elderly Isolated Systolic Hypertension (VALISH) Study: Rationale and Design

Toshio OGIHARA, Takao SARUTA, Hiroaki MATSUOKA, Kazuaki SHIMAMOTO, Tos ...

2004 年 27 巻 9 号 p. 657-661
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.657

ジャーナルフリー

抄録を表示する抄録を非表示にする

Although antihypertensive therapy has been proven to reduce cardiovascular morbidity and mortality, it is unclear how much blood pressure should be decreased in elderly patients with hypertension. The Valsartan in Elderly Isolated Systolic Hypertension (VALISH) study is a multicenter parallel-group study comparing the incidence of cardiovascular events between two target systolic blood pressure levels, below 140 mmHg and below 150 mmHg, under treatment with valsartan, an angiotensin II receptor blocker, as an initial antihypertensive drug in elderly patients with isolated systolic hypertension. The number of patients to be recruited is 3,000 and the duration of follow-up is at least 2 years. This 3,000-patient trial was designed with a two-sided α level of 0.05 and 80% power to detect the difference in incidence of cardiovascular events between the target blood pressure levels based on estimation of the cardiovascular events ratio as 21.5/1,000 patient-years and 29.1/1,000 patient-years for the two blood pressure levels. The VALISH study, a large-scale investigator-initiated trial in Japan, will determine whether age should be considered in setting target blood pressure in treatment of isolated systolic hypertension in elderly patients. (Hypertens Res 2004; 27: 657-661)

抄録全体を表示

PDF形式でダウンロード (87K)
The Methylentetrahydrofolate Reductase Gene Variant (C677T) as a Risk Factor for Essential Hypertension in Caucasians

Stephanie HEUX, Fabien MORIN, Rod A. LEA, Micky OVCARIC, Lofti TAJOURI ...

2004 年 27 巻 9 号 p. 663-667
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.663

ジャーナルフリー

抄録を表示する抄録を非表示にする

Essential hypertension (EH) is a common, multifactorial disorder likely to be influenced by multiple genes of modest effect. The methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation is functionally important, being strongly associated with reduced enzyme activity and increased plasma levels of homocysteine. Mild hyperhomocysteinemia is a known risk factor for cardiovascular disease (CVD) and hypothesised also to be involved in hypertension pathophysiology. The present study was performed to determine the prevalence of the 677T mutation in Australian Caucasian patients diagnosed with EH and to test whether the C677T variant is associated with the disorder. A case-control cohort, consisting of 250 EH patients and 250 age, sex and racially matched normotensive controls, were used for the association study. Comparison of C677T allele frequencies revealed a higher proportion of the mutant allele (T) in the EH group (40%) compared to unaffected controls (34%) (p =0.07). Furthermore, genotypic results indicated that the prevalence of the homozygous mutant genotype (T/T) in the affected group was higher than that of controls (14%:10%) (p =0.17). Interestingly, conditional logistic regression showed that the MTHFR C677T mutation conferred a mild, yet significant increase in risk of essential hypertension after adjusting for body mass index (odds ratio=1.57, 95% confidence interval: 1.04-2.37, p =0.03). These findings require further investigation in large independent samples, but suggest that essential hypertension, like CVD, may be mildly influenced by the MTHFR C677T variant. (Hypertens Res 2004; 27: 663-667)

抄録全体を表示

PDF形式でダウンロード (30K)
Excessive Alcohol Intake Increases the Risk of Arterial Stiffening in Men with Normal Blood Pressure

Takashi KURIHARA, Hirofumi TOMIYAMA, Hideki HASHIMOTO, Yoshio YAMAMOTO ...

2004 年 27 巻 9 号 p. 669-673
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.669

ジャーナルフリー

抄録を表示する抄録を非表示にする

Excessive alcohol intake is a known atherosclerotic cardiovascular risk factor. However, the relation between excessive alcohol intake and atherosclerotic cardiovascular risk in subjects with normal blood pressure has not been fully elucidated. This cross-sectional study investigated the relationship between alcohol intake and arterial stiffness, as assessed using brachial-ankle pulse wave velocity, in men with normal blood pressure. Middle-aged male workers who were found to have a normal blood pressure during an annual health check-up performed in May-July 2000 (n =1,682) were enrolled in the study. The subjects’ laboratory data were analyzed, and information on drinking and smoking habits was obtained by a self-administered questionnaire. The brachial-ankle pulse wave velocity was measured using volume plethysmography. The mean brachial-ankle pulse wave velocities of men with an alcohol intake of 40-59 g/day and ≥60 g/day were larger than those of non-drinkers and men with an alcohol intake of <20 g/day. A multivariate general linear model was used to identify the association between alcohol intake and brachial-ankle pulse wave velocity after controlling for other risk factors using a multivariate analysis. An alcohol intake of more than 60 g of ethanol/day was significantly associated with an elevated brachial-ankle pulse wave velocity, after controlling for conventional atherosclerotic cardiovascular risk factors. In conclusion, the present results suggest that excessive alcohol intake increases the atherosclerotic cardiovascular risk associated with arterial stiffening in men with normal blood pressure. (Hypertens Res 2004; 27: 669-673)

抄録全体を表示

PDF形式でダウンロード (45K)

Experimental studies

Genistein Inhibits Expressions of NADPH Oxidase p22phox and Angiotensin II Type 1 Receptor in Aortic Endothelial Cells from Stroke-Prone Spontaneously Hypertensive Rats

Jin-Wen XU, Katsumi IKEDA, Yukio YAMORI

2004 年 27 巻 9 号 p. 675-683
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.675

ジャーナルフリー

抄録を表示する抄録を非表示にする

Phytoestrogens are considered to be natural selective estrogen receptor modulators exerting antioxidant activity and improving vascular function. However, the mechanisms responsible for their antioxidative effects remain largely unknown. This study tested the hypothesis that genistein may provide significant endothelial protection by antioxidative effects through attenuating NADPH oxidase expression and activity. The results showed that genistein suppressed the expressions of the p22phox NADPH oxidase subunit and angiotensin II (Ang II) type 1 (AT1) receptor in a concentration- and time-dependent manner in aortic endothelial cells from stroke-prone spontaneously hypertensive rats examined by Western blot analysis. Treatment with genistein also remarkably reduced the Ang II-induced superoxide by the reduction of nitroblue tetrazolium, inhibited nitrotyrosine formation, and attenuated endothelin-1 production by ELISA via the stimulation of Ang II. However, when cells were pretreated with ICI-182780, an estrogen-receptor antagonist, at a concentration of 50 μmol/l for 30 min and then co-incubated with ICI-182780 and genistein for 24 h, the inhibitory effect of genistein was not blocked. In contrast, the inhibitory effect of genistein treatment was partially reversed by 30-min pretreatment of endothelial cells with GW9662, a peroxisome proliferator-activated receptor γ (PPARγ) antagonist. Genistein thus appears to act as an antioxidant at the transcription level by the downregulation of p22phox and AT1 receptor expression. Our data also showed that the PPARγ pathway was involved, at least in part, in the inhibitory effect of genistein on the expression of p22phox and AT1 receptors. The endothelial-protective effects of phytoestrogen may contribute to improvement of cardiovascular functions. (Hypertens Res 2004; 27: 675-683)

抄録全体を表示

PDF形式でダウンロード (384K)
Effects of Angiotensin II Type 1 Receptor Antagonist on Smooth Muscle Cell Phenotype in Intramyocardial Arteries from Spontaneously Hypertensive Rats

Makoto KUBO, Seiji UMEMOTO, Kozo FUJII, Shinichi ITOH, Masakazu TANAKA ...

2004 年 27 巻 9 号 p. 685-693
発行日: 2004年
公開日: 2005/03/04

DOIhttps://doi.org/10.1291/hypres.27.685

ジャーナルフリー

抄録を表示する抄録を非表示にする

To clarify the precise mechanisms involved in the reduced coronary flow reserve in hypertension, we compared the effects of the angiotensin II type 1 (AT₁) receptor antagonist FK-739 with those of the angiotensin-converting enzyme (ACE) inhibitor enalapril for 6 weeks on the smooth muscle (SM) cell phenotype in intramyocardial arteries from male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Compared with WKY, SHR showed a significant increase in left ventricular (LV) hypertrophy and fibrosis, blood pressure (BP), and vascular remodeling of the intramyocardial arteries, and a significant decrease in endothelial NO synthase and the contractile-type myosin heavy chain isoform SM2 of the intramyocardial arteries as well as calponin 1 and GATA-6. In the hearts of SHR, both drugs equivalently and significantly reduced BP, which was still significantly higher than that in the WKY groups, and also reduced LV hypertrophy and fibrosis, whereas endothelial NO synthase was significantly restored. Although both drugs showed little effect on the vascular remodeling of the intramyocardial arteries in the SHR hearts, FK-739, but not enalapril, significantly restored SM2 and GATA-6 in the SHR hearts to the same levels as those of the vehicle WKY group. The effects of the two drugs on these indices were not observed in the three WKY hearts. Thus, the AT₁ receptor antagonist may modulate the SM cell phenotype toward the contractile-type more effectively than the ACE inhibitor before the morphological changes occur in the intramyocardial arteries of the SHR hearts. (Hypertens Res 2004; 27: 685-693)

抄録全体を表示

PDF形式でダウンロード (679K)

J-STAGEへの登録はこちら（無料）