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ABSTRACT: Discusses evaluating blood pressure (BP) behavior outside of the clinical setting and during daily activities to identify high-risk subjects. It is concluded that various valuable information on the cardiovascular system can be obtained using multifunctional ambulatory BP monitors. Wearable monitoring of BP and other cardiovascular variables would be useful for chronobiological strategy for risk stratification and more effective individualized prevention and treatment of cardiovascular events.
IEEE Engineering in Medicine and Biology Magazine 06/2003; · 2.06 Impact Factor
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ABSTRACT: Early-morning blood pressure is generally viewed as an important therapeutic target, for two reasons. First, for antihypertensive agents taken once daily in the morning, the timing of the trough plasma drug level, and thereby the lowest pharmacodynamic effect, often coincides with the early morning rise in blood pressure and heart rate. Evidence has been accumulated to suggest that blood pressure control throughout the 24 h period may be necessary to gain complete benefit from antihypertensive medication. In fact, in a longitudinal study, the regression of cardiac hypertrophy in patients with hypertension was more accurately predicted by treatment-induced changes in average 24 h ambulatory blood pressure than by clinic or home-monitored blood pressure readings. The other reason for the importance of morning blood pressure is that cardiovascular risk is heightened at this time of day. A morning surge in sympathetic activity alters haemodynamic forces and predisposes vulnerable coronary atherosclerotic plaques to rupture. At the same time as this risk of plaque rupture is greatest, circadian variations in haemostatic and fibrinolytic factors result in morning hypercoagulability and hypofibrinolysis, promoting the formation of intraluminal thrombi. We recently showed that, in older hypertensives, a greater morning blood pressure surge, mediated at least in part by an exaggerated alpha-sympathetic activity, is associated with more advanced silent cerebrovascular disease as well as a higher future incidence of stroke. The early morning surge in blood pressure could become a new therapeutic target for preventing target-organ damage and subsequent cardiovascular events in hypertension. Of greatest interest is the potential benefit of a chronotherapeutic approach, involving, for example, long-acting chronoformulations, which has not yet been extensively studied.
Blood Pressure Monitoring 01/2002; 6(6):349-53. · 1.52 Impact Factor
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ABSTRACT: This study reports on the associations among depression, anxiety, awake physical activity, sleep quality (assessed by nocturnal physical activity), and diurnal blood pressure (BP) variation in a nonpsychiatric sample (The Work Site Blood Pressure Study). We conducted ambulatory BP (ABP) monitoring and actigraphy in 231 working men and women. Depression and anxiety were measured by the Brief Symptom Inventory. There were gender-specific associations between depression or anxiety and ABP parameters. In men, depression was associated positively with the sleep/awake systolic BP (SBP) ratio (r=0.24, P=0.006). After controlling for age, body mass index, and awake and sleep activity, depression remained significantly associated with the sleep/awake SBP ratio (r=0.25, P=0.005) and was also significantly related to sleep SBP (r=0.21, P=0.02). Anxiety, which was related to depression (r=0.73, P<0.0001), had a similar but slightly weaker pattern of associations with ABP and activity. These associations were not found in women, but there were associations of anxiety with awake SBP (r=0.24, P=0.01) and pulse rate (r=0.27, P=0.006). In conclusion, depression is associated with disrupted diurnal BP variation independent of ambulatory physical activity in working men, whereas anxiety is associated with awake SBP and pulse rate in women.
Hypertension 11/2001; 38(5):997-1002. · 6.21 Impact Factor
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ABSTRACT: Blood pressure increases transiently after a major earthquake, but the characteristics and the mechanism of this increase are unknown.
The study involved 124 elderly hypertensive outpatients from two clinics near the epicenter of the Hanshin-Awaji earthquake (7.2 on the Richter scale) for whom ambulatory blood pressure monitoring and assessment of end-organ damage had been performed before the earthquake.
During the 1 to 2 weeks after the earthquake, while major aftershocks persisted, mean (+/- SD) systolic blood pressure was 14 +/- 16 mm Hg greater and mean diastolic blood pressure was 6 +/- 10 mm Hg greater, but these values returned to baseline by 3 to 5 weeks after the earthquake. The earthquake-induced increase in blood pressure correlated significantly with the "white coat" effect ([clinic systolic blood pressure minus 24-hour systolic blood pressure] r = 0.34, P <0.001), body mass index (r = 0.28, P <0.001), and age (r = 0.24, P <0.01). The earthquake-induced blood pressure increase was prolonged in patients with microalbuminuria for at least 2 months after the earthquake, whereas it was less pronounced in patients who had been treated with an alpha-blocker and in patients with diabetes mellitus.
These elderly patients with hypertension had a substantial increase in blood pressure after a major earthquake; the increase was usually transient, except in patients who had microalbuminuria. The correlation with white-coat hypertension suggests that both phenomena are related to sympathetic activation.
The American Journal of Medicine 10/2001; 111(5):379-84. · 5.43 Impact Factor
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ABSTRACT: In Japan, a national survey indicated that only 7% of hypertensive patients had a blood pressure less than 140/90 mmHg. There have been no reports of studies investigating all of the prevalence of hypertension, the percentage of subjects who are aware of hypertension, the percentage being treated, and the percentage that are well-controlled (awareness, treatment and control, respectively) among hypertensives in the Japanese general population.
To investigate the prevalence of hypertension, and awareness, treatment and control of hypertension among hypertensives in a Japanese rural population.
A cross-sectional analysis of base-line data of the Jichi Medical School Cohort Study.
Twelve rural communities is 8 prefectures in Japan.
Community-dwelling people who participated in the health examination program in 1992-1995.
Blood pressure (BP) measured once in the sitting position after a 5-minute rest using oscillometric automatic BP monitors (BP203RV-II; Nippon Colin, Japan), and history of hypertension assessed using a self-administered questionnaire.
We analyzed data from 11,302 subjects (4,415 men and 6,887 women). The mean (standard deviation) age was 55(12) years for men and 55(11) years for women. Mean systolic BP and diastolic BP levels were, respectively, 131(21) mmHg and 79(12) mmHg for men and 128(21) mmHg and 76(12) mmHg for women. Prevalence of hypertension (systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg or on antihypertensive medication) was 37% for men and 33% for women. Percentages for awareness (on medication or present past history), treatment and control (both systolic BP < 140 mmHg and diastolic BP < 90 mmHg) were, respectively, 39%, 27% and 10% for men and 46%, 38% and 13% for women.
About one third of the study popUlation were hypertensive, and awareness, treatment and control of hypertension among the hypertensives were 43%, 34% and 12%, respectively. Less than half of the hypertensives were well-controlled even when measurement bias was considered. In the rural Japanese population, improvements are required with regard to awareness, treatment and control of hypertension.
[Nippon kōshū eisei zasshi] Japanese journal of public health 10/2001; 48(10):827-36.
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ABSTRACT: It remains uncertain whether abnormal dipping patterns of nocturnal blood pressure influence the prognosis for stroke. We studied stroke events in 575 older Japanese patients with sustained hypertension determined by ambulatory blood pressure monitoring (without medication). They were subclassified by their nocturnal systolic blood pressure fall (97 extreme-dippers, with >/=20% nocturnal systolic blood pressure fall; 230 dippers, with >/=10% but <20% fall; 185 nondippers, with >/=0% but <10% fall; and 63 reverse-dippers, with <0% fall) and were followed prospectively for an average duration of 41 months. Baseline brain magnetic resonance imaging (MRI) disclosed that the percentages with multiple silent cerebral infarct were 53% in extreme-dippers, 29% in dippers, 41% in nondippers, and 49% in reverse-dippers. There was a J-shaped relationship between dipping status and stroke incidence (extreme-dippers, 12%; dippers, 6.1%; nondippers, 7.6%; and reverse-dippers, 22%), and this remained significant in a Cox regression analysis after controlling for age, gender, body mass index, 24-hour systolic blood pressure, and antihypertensive medication. Intracranial hemorrhage was more common in reverse-dippers (29% of strokes) than in other subgroups (7.7% of strokes, P=0.04). In the extreme-dipper group, 27% of strokes were ischemic strokes that occurred during sleep (versus 8.6% of strokes in the other 3 subgroups, P=0.11). In conclusion, in older Japanese hypertensive patients, extreme dipping of nocturnal blood pressure may be related to silent and clinical cerebral ischemia through hypoperfusion during sleep or an exaggerated morning rise of blood pressure, whereas reverse dipping may pose a risk for intracranial hemorrhage.
Hypertension 10/2001; 38(4):852-7. · 6.21 Impact Factor
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ABSTRACT: Elevated plasma homocyst(e)ine is a risk factor for cardiovascular disease (CVD) in many populations, but the relationship between homocyst(e)ine and CVD in Japanese subjects has been unclear. It has been hypothesized that the link between homocyst(e)ine and CVD may be mediated in part by activation of coagulation and endothelial cell injury in the elderly Japanese subjects. To further evaluate this hypothesis, the present cross-sectional study was designed to assess the relationships among plasma homocyst(e)ine concentrations, risk of CVD, and markers of coagulation (fibrinogen, FVII, F1+2, FVIIa and FXIIa) and endothelial cell damage (vWF and thrombomodulin) in 146 elderly Japanese subjects (79 healthy controls and 67 patients with CVD). The geometric mean (range) of plasma homocyst(e)ine concentrations was 10.2 (3.2--33) micromol/l in 79 Japanese healthy elderly subjects. As expected, healthy female and male elderly subjects had homocyst(e)ine levels that were 2.5 and 5.3 micromol/; higher, respectively, compared to healthy young control subjects (n=62). Healthy young and elderly men had homocyst(e)ine levels that were 1.7 and 4.5 micromol/l higher, respectively, compared to values in women. This higher plasma homocyst(e)ine levels in the elderly subjects were negatively correlated with levels of folic acid, albumin and total cholesterol, but were not significantly related to markers of coagulation or endothelial cell-damage. The results of multiple logistic regression analyses suggested that high homocyst(e)ine levels were independently related to CVD risk. In addition, levels of FVIIa, and F1+2 were significantly higher in elderly Japanese patients with CVD compared to elderly subjects without CVD, but were unrelated to plasma homocyst(e)ine concentrations. In summary, elevated plasma concentrations of homocyst(e)ine, FVIIa, and F1+2 were associated with increased risk of CVD in elderly male and female Japanese subjects, but the association between homocyst(e)ine and CVD was unrelated to abnormalities in markers of coagulation and endothelial cell damage in this population.
Atherosclerosis 09/2001; 157(2):441-9. · 3.79 Impact Factor
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ABSTRACT: Congenital protein C deficiency is now widely recognized as a genetic risk for venous thrombosis. However, it remains uncertain whether this condition also confers risk for arterial thrombosis. We evaluated the association of congenital protein C deficiency with hypertension and silent cerebrovascular disease using brain magnetic resonance imaging (MRI) (T1- and T2-weighted and proton density images) in a large family pedigree of protein C deficiency diagnosed by gene analysis, compared with 46 non-pedigree related control subjects with normal protein C levels (> or = 75%) who were selected from among 55 asymptomatic hypertensive subjects matched for age and cardiovascular risk factors. Of the 58 living subjects in this pedigree, we measured plasma protein C levels in 45 subjects, and found 2 cerebral infarctions in the 24 heterozygotic subjects, whereas there was no stroke in the 21 normal homozygotic subjects. We performed brain MRI in 14 asymptomatic hypertensive subjects without any cardiovascular disease and in two patients with cerebral infarction, and found 28 cerebral infarcts (two corresponded to the patients' neurologic deficits and 26 were silent). All were lacunar infarcts < 10 cm in size. A total of 25 silent lacunar infarcts were found in nine heterozygotic subjects, whereas only one was found in the seven normal homozygotic subjects (2.8 v 0.14 lacunes per person, P = .002). No advanced white matter hyperintense lesions in T2-weighted images were found in either group. The prevalence of silent lacunar infarcts in the heterozygotic subjects was also significantly higher than that in normal control subjects (1.0 per person, P = .01). Concerning the distribution of silent infarcts, the number of lacunes located in the basal ganglia was higher in the heterozygotic subjects (2.3 per person, P < .001) than in the seven normal homozygotic subjects (0.14 per person) or in the control group (0.28 per person), whereas the number of lacunes in the white matter was not different among the groups. In conclusion, congenital protein C deficiency may accelerate the progression of silent cerebral infarct formation in hypertension, particularly in the basal ganglia, and may be a potential risk for stroke or vascularly induced dementia.
American Journal of Hypertension 08/2001; 14(8 Pt 1):818-22. · 3.18 Impact Factor
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ABSTRACT: The present study investigated whether the circadian rhythm of sympathovagal activity is related to the severity of coronary spasm or multivessel coronary spasm. Heart rate variability was examined in 22 consecutive patients with vasospastic angina provoked by intracoronary injection of acetylcholine, who had either multivessel spasm (Group M, n=11 ) or single vessel spasm (Group S, n= 11), in 20 subjects without coronary artery disease (Group C) and 20 patients with effort angina who had organic coronary artery stenosis (Group E). The frequency domain indices were analyzed, including low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4Hz), the latter being an index of efferent parasympathetic activity, and the ratio (L/H) as an index of sympathovagal balance. The circadian variation of the parameters was analyzed by its pattern and was quantified by the difference of the mean values between daytime and nighttime. Although the HF power increased during nighttime in Groups C and S, this increase was attenuated in Groups E and M. The circadian variation of the L/H ratio (ie, a drop during nighttime) was smaller in the S and M groups than in Groups C and E. Accordingly, in Group M, the circadian variation of both sympathetic and parasympathetic nervous activity was attenuated, but in Group S, the variation of sympathetic nervous activity, but not parasympathetic nervous activity, was decreased. These data suggest that relatively enhanced sympathetic nervous activity at night may be involved in the mechanism underlying multivessel coronary spasm.
Japanese Circulation Journal 08/2001; 65(7):593-8.
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ABSTRACT: The aim of the present study was to clarify the differences in the progression and the characteristics of silent cerebral infarcts (SCI) between patients with coronary artery disease (CAD) and hypertensive patients. Silent cerebral infarcts, a powerful prognostic indicator for stroke, are frequently found in patients with CAD and in hypertensives. However, the differences in the characteristics of SCI and related risk factors between CAD and hypertensive patients have not been thoroughly investigated. We evaluated the number of SCI and their distribution using brain magnetic resonance imaging (T1- and T2-weighted images) in 107 patients with CAD (validated by coronary angiography) and 101 hypertensive patients without history of clinical stroke. The prevalence of multiple SCI (three or more infarcts per person) in patients with CAD and with hypertension was significantly higher than in hypertensives without CAD (46% v 21%; P = .001), whereas that of patients with CAD without hypertension was intermediate (31%). The patients with multi- (two- or three-vessel) vessel diseases (VD) had a significantly higher prevalence of multiple SCI than the hypertensives and the no-stenosis or 1-VD group (68.1% in the 3-VD group, 52.0% in the 2-VD group, 26.8% in the 1-VD group, and 21.0% in the no-stenosis group). Multiple logistic regression analysis revealed that in the CAD group, the number of involved coronary arteries was an independent determinant of SCI (P < .005), whereas in the hypertensive group, age was an independent determinant of SCI (P < .005). When we investigated the distribution of SCI, in the CAD group, SCI in the deep perforator territory (the basal ganglia and the thalamus) were independently associated with the number of involved coronary arteries (P < .005), whereas SCI in the white matter were independently associated with age only (P < .005). In conclusion, SCI were more advanced in the patients with multivessel CAD than in the hypertensive patients, and were more common in patients with CAD and hypertension than in those without hypertension. Coronary atherosclerosis was independently and specifically associated with SCI located in the deep perferator territory but not of SCI located in the white matter. The CAD-atherosclerosis and hypertension may be independently involved in the pathologic process of SCI.
American Journal of Hypertension 06/2001; 14(6 Pt 1):509-15. · 3.18 Impact Factor
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Y Hojo,
U Ikeda,
K Ohya,
M Ichida, K Kario,
M Takahashi,
M Ikeda,
S Minota,
Y Isumi,
N Minamino,
T Ishimitsu,
K Shimada
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ABSTRACT: Adrenomedullin (AM), a potent vasodilator peptide, has natriuretic effects, and its plasma concentration is elevated in cardiovascular diseases. In the present study, we investigated the induction of AM expression due to interactions between THP-1 cells (human monocytic cell line) and human umbilical cord vein endothelial cells (HUVECs). AM levels in the culture medium were measured by radioimmunoassay. The luciferase vector containing the 5'-flanking region of the human AM gene was transfected into either HUVECs or THP-1 cells. Addition of THP-1 cells to HUVECs for 48 h induced marked increases in AM levels, which were 16-fold higher than those of HUVECs alone. Luciferase vectors containing the 5'-flanking region of human AM gene (pLCF-1534) were transferred into THP-1 cells or HUVECs. Addition of THP-1 cells to pLCF-1534-transfected HUVECs induced an increase in luciferase activity in cell lysates, which was 5-fold higher than that of the transfected HUVECs alone. In contrast, the luciferase activity of lysates from pLCF-1534-transfected THP-1 cells was not affected by coculture with HUVECs. A separate coculture experiment revealed that direct contact of THP-1 cells and HUVECs contributed to enhanced AM production in the cocoulture. Co-incubation of the cell membrane fraction from THP-1 cells augmented AM production by HUVECs. Both anti-interleukin (IL)-1alpha antibody and IL-1 receptor antagonist significantly inhibited AM production in the cocultures. The cell-to-cell interaction between monocytes and HUVECs induces AM production by HUVECs, which may play an important role in the pathogenesis of vascular disorders.
Atherosclerosis 05/2001; 155(2):381-7. · 3.79 Impact Factor
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ABSTRACT: We sought to study the association of the silent cerebral infarct (SCI), a predisposing condition of stroke, with hyperinsulinemia and hemostatic abnormalities in older hypertensive subjects.
Hypertension is a powerful risk factor for stroke. However, the role of other risk factors for stroke in hypertensive subjects remains incompletely understood.
We performed brain magnetic resonance imaging and measured cardiovascular risk factors, by administering the 75-g oral glucose tolerance test and measuring plasma insulin and hemostatic variables, in 123 asymptomatic hypertensive subjects (mean age 69 years).
At least one SCI was detected in 80 subjects (65%), and multiple SCIs were found in 48 subjects (39%). The presence of SCIs was associated with older age, higher levels of 24-h systolic blood pressure, 2-h insulin, thrombin-generation markers (prothrombin fragment 1+2 and thrombin-antithrombin complexes), plasminogen activator inhibitor-1 (PAI-1), D-dimer and von Willebrand factor (vWF), but not with plasmin-alpha2-plasmin complex (PIC) levels. The 2-h insulin area under the curve (AUC) was positively correlated with PAI-1 and vWF levels (p < 0.01), and the PAI-1 level was negatively correlated with the PIC level (p < 0.02). Multiple logistic regression analysis revealed that age and the 2-h insulin AUC were significantly associated with SCIs, particularly those located in the subcortical white matter, and hemostatic abnormalities were significantly associated with the presence of multiple SCIs, particularly those located in the basal ganglia.
In older asymptomatic hypertensive subjects, hyperinsulinemia appears to be associated with lacunar-type SCIs, particularly those located in the subcortical white matter, and hemostatic abnormalities show an association with the presence of multiple SCIs, particularly those located in the basal ganglia.
Journal of the American College of Cardiology 03/2001; 37(3):871-7. · 14.16 Impact Factor
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Current Hypertension Reports 01/2001; 2(6):495-6. · 2.50 Impact Factor
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ABSTRACT: To develop a perceived social support scale for the Japanese.
Participants consisted of a total of 2,150 residents who responded to a perceived social support scale questionnaire in four communities involved in the Jichi Medical School Cohort Study at the study baseline in 1992-1994 (Analysis I) and 380 residents of Akaike town who responded to a questionnaire survey with the revised scale in 1999 (Analysis II). The first analysis was performed to confirm cross validity of the perceived social support scale measuring the availability of functional support from the spouse, family, and friends. The factor structures estimated for each district were compared with each other. The second analysis was set to revise the scale, modified in terms of a 4-point scoring format. The correlation between each item and a social desirability scale score, Cronbach alpha, and correlation coefficients between the revised scale scores and the original scale scores were calculated.
Cross validity was confirmed based on the similarity of the factor structures of the responses obtained from the four different communities. Four selected indices supported the constancy of the factor structures across the communities. For the revised scale, two items were removed from the original scale-items measuring spousal support because of their statistically significant correlations with the social desirability scale score. The first principal component accounted for 57.0% of variance for spousal support, 68.2% for family support, and 67.0% for friends support and uni-dimensionality of the scales was confirmed. Alpha coefficients of the scales were .89, .95, and .94, respectively. Social support levels were stable over a mean period of 6.2 years.
On an empirical basis, we have been able to develop a perceived social support scale. Homogeneous data from three different sources were obtained which were free from social desirability response bias and thus applicable for Japanese adults.
[Nippon kōshū eisei zasshi] Japanese journal of public health 11/2000; 47(10):866-78.
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ABSTRACT: To investigate the determinants of endothelial cell damage in hypertensive elderly patients, we measured the plasma von Willebrand factor (vWF) levels by a recently developed enzyme-linked immunosorbent assay using monoclonal antibody for the functional epitope. Plasma vWF level was markedly increased in the elderly normotensive subjects (n = 42) than in younger normotensive subjects (n = 39) (127 vs 88%, p < .0001), and was further increased in elderly hypertensive subjects (n = 68) (148%, p < .05 vs elderly normotensives). The vWF level was positively correlated with body mass index in younger normotensive subjects (r = 0.41, p < .01), with systolic blood pressure (BP) in elderly normotensive subjects (r = 0.41, p < .01), and with age (r = 0.44, p < .001) and fibrinogen level (r = 0.37, p < .01) in elderly hypertensive subjects. In elderly hypertensive subjects (n = 150), vWF level had a stronger positive correlation with 24-hr systolic BP measured (r = 0.41, p < .0001) by ambulatory BP monitoring than with clinic systolic BP (r = 0.33, p < .0001). In conclusion, in hypertensive elderly patients, endothelial cell damage increases with systolic BP and fibrinogen levels, indicating a prethrombotic condition.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 05/2000; 37(5):393-7.
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ABSTRACT: C-reactive protein (CRP) is an acute-phase reactant that is related to future cardiovascular events. However, little is known about the long-term intra-individual stability of CRP in community residents. The 5-year intra-individual correlation of CRP levels was examined in the Jichi Medical School Cohort Study in Japan. CRP measurements were obtained in 1993 and in 1998 from 388 presumptively healthy individuals aged 30-69 years at baseline. The Pearson's correlation coefficient of CRP between baseline and follow-up measurements was 0.43 (95% confidence interval (CI): 0.34-0.51). Additional analyses by sex and smoking status at baseline revealed similar coefficients. The correlation coefficient of CRP was lower than that of other classical risk factors, such as body-mass index (BMI), blood pressure, and total and high-density lipoprotein (HDL) cholesterol. A subgroup of individuals with higher levels of CRP at both baseline and follow-up measurements had higher BMI, hemoglobin Alc, and plasma fibrinogen, and lower levels of HDL-cholesterol than others, even after adjusting for age, sex, and smoking status in a multiple logistic model. In conclusion, the stability of CRP levels was statistically significant in a long-term population-based study. A subgroup with higher levels of CRP who had an aggregation of cardiovascular risk factors was identified by the 2 measurements.
Japanese Circulation Journal 05/2000; 64(4):303-8.
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ABSTRACT: Abnormal nocturnal blood pressure (BP) dipping status may be partly determined by nocturnal sympathetic activity. We studied the effect of nighttime dosing of an alpha(1)-adrenergic blocker, doxazosin, on the BP dipping status of 118 hypertensives, all of whom underwent 24-hour ambulatory BP monitoring before and after treatment. The mean nighttime/daytime ratio of systolic BP was increased (0.91 after therapy versus 0.89 at baseline, P<0.05). The patients were initially divided into 4 groups on the basis of their dipping status at the baseline assessment: 18 (15%) were extreme dippers, with a nighttime systolic BP fall of at least 20% of daytime BP; 46 (39%) were dippers (fall between 10% and 20%); 48 (41%) were nondippers (fall between 0% and 10%); and 6 (5%) were risers (nocturnal increase of systolic BP). A shift in dipping status toward less nocturnal BP dipping was observed after doxazosin therapy (P<0.05). Dipping status was determined by nighttime more than by daytime BP, and this was not explained by differences in the number of daytime and nighttime readings. The effects of doxazosin on the mean nocturnal systolic BP changes were an increase of 4.3 mm Hg in extreme dippers and decreases of 0.7 mm Hg in dippers, 12 mm Hg in nondippers, and 18 mm Hg in risers; the reduction was only significant in the latter 2 groups (both P<0.01). To estimate the effects of regression to the mean on the changes in dipping status, we also defined dipping status with the average of the BPs before and after doxazosin and found no difference in the degree of nighttime BP reduction among each group. The reduction of daytime BP was now significantly greater in the subgroups with less dipping: 6. 4 mm Hg for extreme dippers and 16 mm Hg for risers (P<0.05). In conclusion, nighttime dosing with doxazosin markedly affects the nocturnal BP dipping status of hypertensives, but the apparently greater reduction in nighttime pressure in nondippers and risers may be, at least partly, due to the effect of regression to the mean. The most important determinants of the effect of doxazosin were the absolute BP levels, both day and night, rather than dipping status per se.
Hypertension 03/2000; 35(3):787-94. · 6.21 Impact Factor
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ABSTRACT: Recently, there have been some reports indicating that calcium antagonists induce a reflex increase in sympathetic activity, triggering cardiac events, especially in coronary artery disease (CAD) patients. In this study, we assessed heart rate (HR) variability (HRV) using power spectral analysis of the 24-h RR interval in 25 hypertensive outpatients with CAD treated with nifedipine. We compared blood pressure (BP), HR, and HRV variation in the same patients substituting benidipine (long-acting) for nifedipine (intermediate-acting). There were no significant differences in 24-h, daytime, nighttime, and morning BP between the nifedipine phase and the benidipine phase. HRV parameters (LF: low frequency power, HF: high frequency power, LF/HF ratio) also showed no significant differences in 24-h, daytime, nighttime, and morning LF, HF, and LF/HF ratio between the nifedipine phase and the benidipine phase. Blood pressure, HR, and HRV parameters, except the LF component from 2 to 4 h after nifedipine administration (the most effective duration), showed no differences compared to before administration. The LF component after the nifedipine administration was lower than before administration. In conclusion, in hypertensive patients with CAD, whose BP levels were well-controlled by twice-daily use of intermediate-acting nifedipine, switching from nifedipine to a long-acting calcium antagonist, benidipine, maintained well-controlled BP levels to a similar degree, but it may not have additional benefit in sympatho-vagal balance.
Hypertension Research 02/2000; 23(1):7-14. · 2.58 Impact Factor
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ABSTRACT: The treatment of high blood pressure (BP) after myocardial infarction is extremely important to decrease reinfarction and mortality. BP should be controlled more strictly in this high-risk hypertensive population. Recently, many clinical trials have demonstrated the benefits of lifestyle modification and antihypertensive agents, particularly beta-blockers and angiotensin-converting-enzyme inhibitors for the treatment of acute myocardial infarction. Treatment with these agents that modify BP may benefit even normotensive patients after a myocardial infarction, although the benefit is greater in hypertensives.
Medical Clinics of North America 02/2000; 84(1):1-21, vii. · 2.47 Impact Factor
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American Journal of Hypertension 12/1999; 12(11 Pt 1):1159-60. · 3.18 Impact Factor
