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Biomedical subjects

Hirofumi Tomiyama

Publications and source records attributed to Hirofumi Tomiyama.

At least 19 recordsLinked to original sources
PubMed2007

Arterial stiffness and progression to hypertension in Japanese male subjects with high normal blood pressure.

OBJECTIVES: This observational study was conducted to compare the significance of the relationship between arterial stiffness and progression to higher blood pressure categories among middle-aged Japanese men with high normal blood pressure (HNP), normal blood pressure (NRP) and optimal blood pressure (OPP). METHODS AND RESULTS: During the 3-year observational period, 100 subjects with HNP developed hypertension (n=475; 42 +/- 9 years), and 175 of those with normal NRP (n=581; 41 +/- 8 years) and 249 of those with OPP (n=702; 39 +/- 8 years) showed progression to higher blood pressure categories. A binary logistic regression analysis adjusted for known risk factors revealed that values of the brachial-ankle pulse wave velocity, a surrogate marker of arterial stiffness, in the highest quartile, as compared with those in the lowest quartile, obtained at the start of the study were significantly predictive of the progression to hypertension [adjusted odds ratio = 9.4 (95% confidence interval, 3.0-29.8), P < 0.01]. The predictive value of this parameter for progression to higher blood pressure categories in subjects with HNP was more significant than that in those with NRP or OPP. CONCLUSIONS: Increased arterial stiffness and elevated blood pressure may be mutually causally related, and it appears that the significance of this relationship may increase with increasing blood pressure, even in subjects without hypertension. Assessment of arterial stiffness may be more reliable for predicting the progression to hypertension in cases of HNP than in cases with NRP or OPP.

Adult↗
PubMed2006

Elevated serum levels of alanine aminotransferase and gamma glutamyltransferase are markers of inflammation and oxidative stress independent of the metabolic syndrome.

The present study attempted to establish whether elevated serum levels of alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) are independent (of each other) markers of systemic inflammation and oxidative stress as assessed by the plasma levels of C-reactive protein (CRP) and lipid peroxides (lipOX), regardless of the presence of underlying metabolic syndrome (as defined by the modified Adult Treatment Panel III (ATPIII) criteria). The plasma levels of CRP and lipOX were determined in 1483 middle-age Japanese men (42+/-9 years). A general linear model analysis indicated that elevated serum ALT and/or serum GGT (levels in the respective highest quartiles) were significantly related to the logarithms of the plasma levels of CRP (Beta=0.08 (0.05-0.11) and 0.08 (0.05-0.11), respectively) and the logarithm of the plasma levels of lipOX (Beta=0.03 (0.01-0.05) and 0.03 (0.01-0.05), respectively), regardless of the presence of underlying metabolic syndrome (MetS) (p<0.01). In addition, the presence of MetS and elevated serum levels of both of these liver enzymes additively increased the plasma levels of CRP and lipOX. Thus, it is proposed that elevated serum ALT and elevated serum GGT are independent markers of the activation of systemic inflammation and increased oxidative stress, independent of their relationship to MetS, and that the presence of MetS and elevations of both of these liver enzymes may additively worsen the atherogenic state.

Adult↗
PubMed2006

B-type natriuretic peptide and arterial stiffness in healthy Japanese men.

BACKGROUND: Recent evidence suggests that even a slight increase in the plasma level of B-type natriuretic peptide (BNP) may be a marker of cardiovascular risk; however, the mechanisms underlying the association are currently unclear. Because increased arterial stiffness, as reflected by an increase of the pulse wave velocity (PWV) or pulse pressure (PP), may contribute to increasing plasma BNP levels, in the present study we investigated the relationships between the plasma BNP level and the PWV and PP, all of which are known markers of cardiovascular risk, in a healthy male Japanese cohort. METHODS: This was a cross-sectional study of 725 healthy Japanese men (age, 54 +/- 4 years). The PWV was assessed by the volume-rendering method. Plasma BNP levels were determined with a high-sensitivity noncompetitive immunoradiometric assay. RESULTS: A univariate linear regression analysis demonstrated that the plasma BNP level was significantly correlated with age (r = 0.20, P < .01), PWV (r = 0.12, P < .01), and PP (r = 0.17, P < .01). A stepwise multivariate linear regression analysis demonstrated that both the PWV and PP were significantly associated with the plasma BNP level, independent of age. CONCLUSION: In healthy Japanese men, stiffening of large arteries, as evidenced by an increase of the PWV or PP, may account at least in part for elevated plasma BNP levels, even within the so-called normal range.

Aged↗
PubMed2006

Menopause is an independent factor augmenting the age-related increase in arterial stiffness in the early postmenopausal phase.

The present study examined whether the menopause augments the age-related increase in brachial-ankle pulse-wave velocity (PWV). In total, 3149 women (ranging in age from 21 to 94 years) undergoing an annual health screening examination were enrolled in a cross-sectional study. Conventional atherosclerotic risk factors were examined, and the brachial-ankle PWV of each subject was determined. The relationship between age and the brachial-ankle PWV assumed the form of a quadratic curve, and the slope of the curve was relatively steeper after the menopause (brachial-ankle PWV = 0.17 x age2 - 0.58 x age + 812) than before (brachial-ankle PWV = 0.23 x age2 - 8.92 x age + 1058). A logistic regression analysis conducted for subjects between the ages of 45 and 56 years (mean age of menopause +/- 2 standard deviations) demonstrated that women who had experienced the menopause at least 6 years previously demonstrated a significant risk of belonging to the highest PWV tertile {adjusted odds ratio: 2.08 (95% confidential interval: 1.04-4.17)}, independent of age and other atherosclerotic risk factors (hypertension, hypercholesterolemia, diabetes mellitus, obesity, and smoking). Thus, this study suggested that the menopause augments the age-related increase in arterial stiffness during the early postmenopausal phase and that this augmentation is probably related, at least in part, to estrogen deficiency. The contribution of this menopause-related increase in arterial stiffness to the risk of cardiovascular disease in postmenopausal women should be further evaluated.

Adult↗
PubMed2006

Concurrent presence of metabolic syndrome in obstructive sleep apnea syndrome exacerbates the cardiovascular risk: a sleep clinic cohort study.

This cross-sectional study was conducted to examine whether the obstructive sleep apnea syndrome (OSAS) is associated with elevation of the pulse wave velocity (PWV) and increase in the plasma levels of C-reactive protein (CRP), both of which are known markers of cardiovascular risk, and also to determine if the concurrent presence of the metabolic syndrome might exacerbate this elevation in the levels of these cardiovascular risk markers in subjects with OSAS. With these objectives, the PWV and serum CRP were measured in 184 subjects attending a sleep clinic. It was found that the PWV and CRP were higher in the subjects with OSAS (n=94) than in those without OSAS (n=90). Furthermore, among the subjects with OSAS, the PWV and CRP were higher in those with the concurrent presence of the metabolic syndrome (n= 41; PWV=1,562+/-19 cm/s; CRP=1.8+/-0.2 mg/l) than in those without metabolic syndrome (n=53; PWV=1,432+/-21 cm/s; CRP=1.2+/-0.1 mg/l) (p<0.05). A general linear model analysis demonstrated that OSAS and metabolic syndrome were independently associated with elevated PWV and increase of the plasma levels of CRP. OSAS appears to be associated with increased cardiovascular risk, as reflected by both elevated PWV and increase of the plasma CRP. The concurrent presence of metabolic syndrome may exacerbate this increase in cardiovascular risk in subjects with OSAS. Therefore, the concurrent presence of metabolic syndrome may constitute an additive cardiovascular risk factor in subjects with OSAS.

Adult↗
PubMed2005

Synergistic acceleration of arterial stiffening in the presence of raised blood pressure and raised plasma glucose.

Arterial stiffness is recognized as a marker of arterial damage and an indicator of cardiovascular risk. This observational study was conducted to examine the synergistic effect of raised blood pressure (RBP; > or =130/85 mm Hg) and raised plasma glucose (RPG; > or =110 mg/dL) even at levels below those conventionally used to define hypertension and diabetes on the rate of increase of the pulse wave velocity (PWV) over a 3-year period in 2080 Japanese men (age 42+/-9 years). First, the subjects were classified into 4 groups based on the presence at the first examination of RBP, RPG, both abnormalities, or neither abnormality. The estimated annual rate of increase of the PWV was higher in subjects with both the abnormalities than in those with either abnormality alone or neither of the 2 abnormalities. Second, the subjects were also classified based on the evolutional status of these abnormalities during the study period; persistence of both of the abnormalities synergistically accelerated the rate of increase of the PWV (68.3+/-7.1 cm/s per year), as compared with the persistence of either abnormality alone (persistence of RBP alone: 18.2+/-1.6 cm/s per year; persistence of RPG alone: 21.2+/-7.4 cm/s per year) or persistence of neither abnormality (11.1+/-0.8 cm/s per year; P<0.01). Thus, blood pressure and fasting plasma glucose levels even below those defining hypertension and diabetes may synergistically lead to progression of arteriosclerotic arterial damage. This synergistic progression may contribute to the additive increases in the risk of cardiovascular events, at least in part.

Adult↗
PubMed2005

Elevated C-reactive protein augments increased arterial stiffness in subjects with the metabolic syndrome.

We examined whether the presence of an increasing number of metabolic syndrome "disorders" was associated with an increasing pulse wave velocity, which is recognized as a marker of cardiovascular risk, and evaluated whether an elevated plasma C-reactive protein level augments this increasing pulse wave velocity. Using a cross-sectional study design, C-reactive protein, metabolic syndrome-related anthropometric parameters, and pulse wave velocity were measured in 5752 middle-aged Japanese men (44+/-10 years old). In linear regression analyses, all of the metabolic "disorders" and the logarithm of the C-reactive protein significantly correlated with pulse wave velocity. Multiple linear regression analysis demonstrated that triglycerides, HDL cholesterol, mean blood pressure, fasting glucose, and the logarithm of the C-reactive protein were significant independent positive predictors of pulse wave velocity (R-square=0.38). The presence of an increasing number of metabolic "disorders" in the subjects was associated with an increasing pulse wave velocity (no disorders 1228+/-139 cm/s > or =3 disorders 1437+/-250 cm/s; P<0.01). Among subjects with the metabolic syndrome, pulse wave velocity was higher in cases with (1508+/-278 cm/s) than in those without an elevated C-reactive protein (1427+/-243 cm/s; P<0.01). In conclusion, an increase in arterial stiffness may constitute a pathophysiological basis for the increased risk of cardiovascular disease in patients with the metabolic syndrome and that an elevated C-reactive protein level may aggravate this cardiovascular risk.

Adult↗
PubMed2005

Insulin sensitivity and endothelial function in hypertension: a comparison of temocapril and candesartan.

BACKGROUND: Recent studies have suggested that angiotensin-converting enzyme inhibitors (ACEi) have a more pronounced effect on endothelial function (END) than angiotensin II receptor blocker (ARB); however, whether this pronounced effect is more beneficial to patients with insulin sensitivity (IS) remains uncertain. The present study compared the effects of ACEi and ARB on END and IS in patients with hypertension. METHODS: A total of 23 patients with hypertension were given either ACEi or ARB alternatively in a cross-over manner for 8-week intervals. Both END and IS were examined after each treatment period; END was assessed by the response of forearm blood flow to reactive hyperemia and IS by an insulin tolerance test. The plasma levels of bradykinin (BK), NOx, tumor necrosis factor (TNF-alpha), and adiponectin (Adi) were also measured after each treatment. RESULTS: We found that END, BK, and NOx were higher after the ACEi treatment than after the ARB treatment. Although the IS and the Adi levels were similar after both treatments, the TNF-alpha level was lower after the ARB treatment than after the ACEi. CONCLUSIONS: We conclude that ACEi and ARB may have similar effects on insulin sensitivity, irrespective of the more pronounced effects of ACEi on endothelial function. The BK-NO pathway might contribute, at least in part, to the pronounced effect of ACEi. On the other hand, the underlying mechanisms affecting insulin sensitivity might differ for both treatments. These results suggest that endothelial function is not a major determinant of insulin sensitivity under physiologic conditions.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2005

Elevated C-reactive protein: a common marker for atherosclerotic cardiovascular risk and subclinical stages of pulmonary dysfunction and osteopenia in a healthy population.

Atherosclerotic cardiovascular disease, osteopenia, and pulmonary dysfunction are the serious health problems, and several experimental studies have suggested that inflammation has a role in them. The present study was conducted to evaluate the usefulness of the plasma CRP is as a common marker for detecting these diseases in the general population in their subclinical stages. In a cross-sectional study, we measured the pulse wave velocity (PWV), quantitative osteo-sono-assessment index (OSI), pulmonary functions, and the plasma level of C-reactive protein (CRP) in 7283 consecutive healthy subjects (age 50+/-11 years). The PWV was higher and the OSI and pulmonary function parameters were below normal in subjects with an elevated CRP level (> or =0.2 mg/dl) than in subjects with a CRP level within the normal range. We divided the subjects into quartiles for each of these parameters and found that the first quartiles represented patients with subclinical states of the aforementioned abnormal conditions. Logistic regression analysis demonstrated that the odds ratios of an elevated CRP level were individually significant in subjects with an elevated CRP level for each abnormality in women and for abnormal PWV and pulmonary dysfunction in men. In conclusion, in addition to being a marker of elevated atherosclerotic cardiovascular risk, elevated plasma CRP seems to be a marker of the early stages of osteopenia and pulmonary dysfunction in healthy subjects.

Adult↗
PubMed2005

Diagnostic value of simultaneous brachial and ankle blood pressure measurements for the extent and severity of coronary artery disease as assessed by myocardial perfusion imaging.

BACKGROUND: Although the simultaneous measurement of brachial and ankle blood pressure is a simple method of evaluating atherosclerosis, its diagnostic value for coronary artery disease (CAD) is undetermined. METHODS AND RESULTS: To evaluate the diagnostic value of ankle-brachial pressure index (ABI) and brachial-to-ankle pulse wave velocity (baPWV), 334 consecutive patients with suspected CAD were evaluated. Patients with a previous myocardial infarction or coronary intervention were not included. The magnitude of myocardial ischemia was evaluated by myocardial perfusion imaging. Using a 20-segment model, the percent of ischemic segments to total segments was expressed as %myocardium ischemic. In patients with < or =1, 2 and > or =3 coronary risk factors, %myocardium ischemic was 2.7+/-0.4, 4.0+/-0.5, 7.9+/-0.8%, respectively (p<0.0001 for trend). Performing ABI with a cutoff of 1, the %myocardium ischemic was similar in patients with < or =1 or 2 risk factors. In patients with > or =3 coronary risk factors, however, an ABI <1 reflected greater %myocardium ischemic than an ABI > or =1 (10.1+/-1.3, 6.6+/-1.0%; p=0.03). No such additional value was observed with baPWV. CONCLUSIONS: The addition of simultaneous brachial and ankle blood pressure measurements will help further stratify patients with multiple risk factors. Although this approach is simple, it facilitates the identification of high-risk patients who require aggressive treatment because >10% myocardium ischemic is regarded as a scintigraphic indicator for coronary revascularization.

Aged↗
PubMed2005

Cut-off value of the ankle-brachial pressure index at which the accuracy of brachial-ankle pulse wave velocity measurement is diminished.

BACKGROUND: The present study was conducted to establish the cutoff value of the ankle-brachial pressure index (ABI) at which the accuracy of brachial-ankle pulse wave velocity (baPWV) measurement is diminished. METHODS AND RESULTS: The baPWV and ABI were measured in 1,361 patients with an atherosclerosis-related disease and 7,889 subjects without any atherosclerotic risk factors, in order to determine the percent difference of the brachial-ankle PWV (%baPWV), the angle of the rise of the anacrotic limb (%angle) and of the amplitude of the entire waveform (%amplitude) in both sides. The %angle and %amplitude were significantly higher in subjects whose %baPWV was >or=19% than in those subjects whose %baPWV was <19% (19% was the mean value+3SD of 7,889 healthy subjects). The %baPWV >or=19% was defined as the abnormal discrepancy of baPWV caused by arterial stenosis in both sides. The receiver operator characteristic curve discriminated the abnormal discrepancy of baPWV by ABI because the area under the curve was 0.86. The highest discriminating sensitivity and specificity were 91% and 75% at ABI =0.95. CONCLUSION: An ABI <0.95 seems to be the marker of diminished baPWV accuracy.

Ankle↗
PubMed2005

Brachial -- ankle pulse wave velocity is a simple and independent predictor of prognosis in patients with acute coronary syndrome.

BACKGROUND: Although a very simple method of measuring brachial -- ankle pulse wave velocity (baPWV) has become available in a clinical setting, whether baPWV can predict future cardiovascular events remains uncertain. We examined whether baPWV is a predictor of cardiovascular events in patients with acute coronary syndrome (ACS). METHODS AND RESULTS: baPWV measurement was performed in 215 consecutive patients with ACS. During the follow-up period (26+/-10 months), 46 patients experienced post-hospitalization cardiovascular events (18 patients experienced a major event (eg, stroke, re-admission for heart failure or cardiac death), and 28 patients experienced coronary re-intervention). A receiver operating characteristic curve demonstrated that the best cut-off point of a baPWV for predicting a post-hospitalization cardiovascular event was 17.00 m/s and that for predicting a major cardiovascular event was 18.00 m/s. After the adjustment for the conventional risk factors influencing the prognosis, a multivariate Cox proportional hazards model demonstrated that both cut-off points of baPWV had a significant hazard ratio for a post-hospitalization event: 5.47 (2.69-11.09) and for a major cardiovascular event: 9.22 (2.78-30.56). CONCLUSIONS: baPWV is a simple predictor of the prognosis of patients with ACS that is independent of conventional risk factors for ACS.

Ankle↗
PubMed2005

Do eicosapentaenoic acid supplements attenuate age-related increases in arterial stiffness in patients with dyslipidemia?: A preliminary study.

The present study was conducted to examine the effect of eicosapentaenoic acid supplements on pulse wave velocity (PWV) in patients with dyslipidemia as a prospective open-labeled study. Eicosapentaenoic acid supplements (1,800 mg/day) were prescribed to 40 patients, and diet therapy in consultation with a nutritionist was conducted in 44 patients as a control group. These interventions were continued for 12 months, and PWV and blood examinations were performed at the start and end of these interventions. PWV increased in the control group but not in the eicosapentaenoic acid group. After adjustment for age, gender, the initial PWV, and the changes in mean blood pressure during the study period, a general linear model univariate analysis post hoc comparison demonstrated that the change in PWV during the period of study was significantly larger in the control group (42 +/- 20 cm/s) than in the eicosapentaenoic acid group (-9 +/- 19 cm/s) (p<0.05). Thus, this preliminary study suggested that eicosapentaenoic acid supplements attenuate age-related increases in arterial stiffness in patients with dyslipidemia. A further study with a larger number of subjects is proposed to confirm this beneficial effect of eicosapentaenoic acid supplements on arterial stiffness.

Aged↗
PubMed2005

[Calcium channel blockers and pulse wave velocity].

Calcium channel blockers (CCB) are widely used in the treatment of hypertension. Recent studies suggest that some CCB improve clinical outcome in patients with cardiovascular diseases. Pulse wave velocity (PWV) is noted as a marker of arterial stiffness. In addition, PWV is thought to be applicable as a marker related to the severity of atherosclerosis and/or predicting future atherosclerotic cardiovascular events. Recent studies suggest that CCB improve structural damage of vascular wall. Further study is proposal to evaluate whether the improvement of structural vascular damage by CCB contribute to the improvement of the prognosis.

Atherosclerosis↗