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ABSTRACT: An exaggerated elevation in blood pressure around waking potentially increases the risk of cardiovascular events, even in individuals with normal blood pressure at other-fold of day. The impact of such a transient blood pressure elevation is disproportionate to its short duration, and the reason has not been elucidated. We hypothesize that individuals with such a blood pressure abnormality receive a cardiovascular overload, even from slight physical activities that are frequently undertaken in daily life.
A total of 16 patients with essential hypertension (52±15 years) staying at hospital for lifestyle education participated in this study. Morning blood pressure elevation was assessed with 24 h ambulatory blood pressure monitoring. Cardiovascular responses to unloaded pedaling, including blood pressure changes, were assessed in a limited maximum exercise test using an electronically braked bicycle ergometer.
Changes in the systolic blood pressure caused by unloaded pedaling correlated positively with the elevation in systolic blood pressure around waking (r=0.52, P=0.05). Moreover, waking elevation of the systolic blood pressure correlated with changes in all of the following cardiovascular variables during unloaded pedaling: heart rate (r=0.69, P=0.003), oxygen consumption (r=0.73, P=0.001), oxygen pulse (r=0.62, P=0.001), and rate pressure product (r=0.64, P=0.008), respectively.
These observations indicate that individuals with prominent blood pressure elevation upon awakening also experience cardiovascular overload from slight physical activities.
Blood pressure monitoring 10/2012; 17(5):198-203. · 1.62 Impact Factor
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ABSTRACT: The present study tested the hypothesis that glomerular filtration rate can predict the onset of hypertension in individuals with normal blood pressure in the general population.
Normotensive individuals (n = 7684) who visited our hospital for a routine physical examination were enrolled in the study (4907 men; mean age 52.1 ± 11.1 years) and were followed up with the endpoint being the development of hypertension. The relationship between estimated glomerular filtration rate at baseline and the incidence of hypertension was evaluated.
During the follow-up period (median 4.0 years; actual follow-up 30 624 person-years), hypertension developed in 2031 participants (66.3 per 1000 person-years). After adjustment for possible risk factors, the hazard ratio of incident hypertension (first tertile as reference) in the second and third tertiles was 1.03 (95% confidence interval 0.92-1.16) and 1.40 (95% confidence interval 1.26-1.57), respectively. Multivariate Cox proportional hazard regression analysis, in which estimated glomerular filtration rate was taken as a continuous variable and adjustments were made for known risk factors, also indicated that baseline estimated glomerular filtration rate independently predicted the onset of hypertension (P < 0.0001). Furthermore, multiple regression analysis revealed that a longitudinal increase in SBP was significantly associated with baseline estimated glomerular filtration rate after adjustment for known risk factors (P < 0.01).
Estimated glomerular filtration rate in normotensive individuals is a good predictor of the onset of hypertension in the general population.
Journal of hypertension 03/2012; 30(3):505-12. · 4.02 Impact Factor
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ABSTRACT: Endothelial damage is an early component of atherosclerosis; however, the impact of cardiovascular risk factors on endothelial function is not clearly understood. We investigated the impact of lipid profiles and high blood pressure on damage.
Japanese male outpatients with grade I or II hypertension, along with gender and age-matched normotensive subjects (both n = 25), were enrolled. Subjects with severe cardiovascular risk factors or illness or those taking medications were excluded. Blood was sampled for laboratory analysis and endothelial function was assessed by flow-mediated dilation (FMD).
Total cholesterol to high-density lipoprotein cholesterol ratio (total-C/HDL-C) was inversely correlated with the FMD value and positively correlated with both malondialdehyde-modified low-density lipoprotein and high-sensitivity C-reactive protein values. Stepwise regression analysis revealed total-C/HDL-C and systolic blood pressure were significant determinants of FMD. Hypertensive subjects had lower FMD values and similar lipid profiles to normotensive subjects. Grouping subjects according to total-C/HDL-C levels showed that those with high values had lower FMD values. Hypertensive subjects with low total-C/HDL-C had similar endothelial index values to those in normotensive subjects with high total-C/HDL-C. Logistic regression indicated hypertension and high total-C/HDL-C were significantly associated with low FMD values.
Impaired endothelial function was associated with increased total-C/HDL-C values, possibly as the result of increased vascular oxidative stress and inflammation. In the early stages of atherosclerosis, the impact of both total-C/HDL-C and BP may be similar in terms of endothelial damage.
Journal of Clinical Lipidology 11/2011; 5(6):460-6. · 1.58 Impact Factor
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International journal of cardiology 02/2011; 147(3):461-3. · 7.08 Impact Factor
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ABSTRACT: The present study was designed to test the hypothesis that brachial-ankle pulse wave velocity (baPWV) predicts longitudinal increases in blood pressure (BP) and new onset of hypertension in individuals with normal BP.
baPWV was measured using a semiautomated device in 2,496 participants (27-84 years) without hypertension who visited our hospital for a yearly health check-up. They were followed up for 4 years with the endpoint being development of hypertension.
During the follow-up period (median, 733 days; actual follow-up, 5,215 person-years), hypertension developed in 698 participants (133.8/1,000 person-years). Kaplan-Meier analysis revealed that risk for hypertension was increased across the tertiles of baseline baPWV. The hazard ratio (first tertile as reference) was 2.02 (95% confidence interval (CI) 1.55-2.64) and 3.49 (95% CI 2.66-4.57) in the second and third tertiles, respectively, after adjustment for possible risk factors. Multivariate Cox proportional hazard regression analysis adjusted for known risk factors, where baPWV was used as a continuous variable, also indicated that the baseline value of baPWV independently predicted new onset of hypertension (P < 0.001). Furthermore, baseline baPWV was significantly associated with a longitudinal increase in BP after adjustment for known risk factors in multiple regression analysis (P < 0.001).
This study provides the first evidence that baPWV is an independent predictor of longitudinal increases in BP as well as of new onset of hypertension.
American Journal of Hypertension 02/2011; 24(6):667-73. · 3.18 Impact Factor
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ABSTRACT: Elevated B-type natriuretic peptide (BNP) levels are predictive of cardiovascular events in patients on chronic maintenance haemodialysis, even in those without apparent cardiovascular disorders when they start dialysis. In the present study, we tested the hypothesis that left ventricular diastolic dysfunction increases BNP levels and can predict cardiovascular events in patients on chronic haemodialysis without apparent cardiac disease.
Patients on chronic maintenance haemodialysis in a stable condition and with normal systolic function were enrolled (n=98). BNP concentrations were measured, and left ventricular diastolic function was assessed using echocardiography after the first dialysis session of the week. Then, they were followed up for 2 years with the end point being the incidence of cardiovascular events.
At baseline, left ventricular diastolic dysfunction was detected in 39 of 98 patients. After adjustment for known risk factors, multivariable regression analysis demonstrated that diastolic dysfunction was a significant predictor of increased BNP levels (P<0.05). During the follow-up period, 17 patients experienced cardiovascular events. Kaplan-Meier analysis demonstrated that the incidence of cardiovascular events was higher in patients with (28.2%) than without (10.2%) left ventricular diastolic dysfunction (log-rank, P<0.01). Univariate Cox proportional hazards regression analysis indicated that diastolic dysfunction and BNP were significant predictors of cardiovascular events (hazard ratio 3.63 and 4.87, respectively; P<0.05).
Left ventricular diastolic dysfunction is associated with increased BNP levels and an increased risk of cardiovascular events in patients on haemodialysis.
Nephrology Dialysis Transplantation 02/2011; 26(2):683-90. · 3.40 Impact Factor
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ABSTRACT: Vascular endothelium, a provider of nitric oxide, is essential for the maintenance of homeostasis in healthy vascular systems. Increased oxidative stress promotes vascular inflammation and is a common pathway involved in endothelial damage. The present study sought to investigate the usefulness of derivative reactive oxygen metabolites (d-ROM) as an oxidative stress marker for detecting endothelial damage in the clinical setting in subjects with early-stage atherosclerosis.
Study 1 investigated the relationship between serum d-ROM levels and cardiovascular risk factors in apparently healthy middle-aged subjects (n = 1992, 49 ± 8 years) who participated in our health checkup program. Study 2 analyzed the association between d-ROM levels and endothelial function assessed by flow-mediated dilation and that between d-ROM levels and high-sensitivity C reactive protein (hs-CRP) levels in middle-aged outpatients with mild-to-moderate cardiovascular risk (n = 43, 40 ± 5 years).
In study 1, the d-ROM level was independently correlated with age, systolic blood pressure, fasting plasma glucose, low-density lipoprotein cholesterol, and brain natriuretic peptide in univariate and multivariate regression analysis. In study 2, the d-ROM level was correlated positively with the hs-CRP level and inversely with the flow-mediated dilation value. Patients in the highest tertile of d-ROM had significantly lower flow-mediated dilation values compared with patients in the other tertiles. Moreover, after subdivision of patients into four groups according to d-ROM and hs-CRP levels, patients with high levels of both d-ROM and hs-CRP showed significantly reduced flow-mediated dilation as compared with those with low levels of both indices.
The close relationship of d-ROM with cardiovascular risk factors, brain natriuretic peptide, inflammatory markers (hs-CRP), and endothelial function (flow-mediated dilation) suggest that d-ROM is a useful oxidative stress marker for detection of endothelial damage in the clinical setting. Assessment of d-ROM, especially combined with hs-CRP, may be a possible predictor of cardiovascular disease.
Vascular Health and Risk Management 01/2011; 7:475-82.
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ABSTRACT: Increased B-type natriuretic peptide (BNP) expression precedes the development of hypertension in spontaneously hypertensive rats. We therefore tested the hypothesis that elevated plasma BNP levels predict the onset of hypertension in normotensive subjects. Japanese normotensive participants who were at our hospital for a yearly physical check-up (mean age 52.7 years, 35.9% women, n=5,026) were enrolled in the study. Blood pressure and BNP were measured at baseline and subjects were followed up for 5 years (median 1,114 d), with the endpoint being the development of hypertension. We evaluated the relationship between plasma BNP levels at baseline and the incidence of hypertension during the follow-up period. Hypertension was defined as systolic or diastolic blood pressure > or =140 or > or =90 mmHg, respectively, or the use of antihypertensive medications. During the follow-up period, hypertension developed in 23.4% (77.0 per 1,000 person-years) and 14.9% (51.0 per 1,000 person-years) of male and female subjects, respectively. Cox proportional hazard regression analysis demonstrated that after adjustment for known risk factors, the risk of hypertension was increased from the first to fourth quartiles of baseline BNP levels. However, after additional adjustment for baseline blood pressure, BNP did not predict the new onset of hypertension. Baseline BNP levels are closely associated with the risk of hypertension in individuals with normal blood pressure, but the prediction of hypertension with BNP is largely dependent on baseline blood pressure. Measurements of BNP may serve as a complementary method for the prediction or confirmation of hypertension.
Hypertension Research 10/2008; 31(9):1737-44. · 2.58 Impact Factor
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ABSTRACT: Each component of the metabolic syndrome is not necessarily clustered coincidentally. Thus, subjects who have obesity, dyslipidemia or impaired glucose tolerance may be at high risk for the development of hypertension. We studied the predictive value of the following for the development of hypertension: obesity (body mass index > or =25.0 kg/m2), dyslipidemia (high-density lipoprotein-cholesterol <40 mg/dL, triglyceride > or =150 mg/dL, or use of anti-dyslipidemic drugs), high normal blood pressure (130 mmHg < or = systolic <140 mmHg, or 85 mmHg < or = diastolic <90 mmHg), and impaired glucose tolerance (fasting plasma glucose > or =110 mg/dL or use of anti-diabetic agents). This observational study included 5,785 subjects without hypertension recruited from participants in our health checkup program. They were followed up for 1,097+/-365 d, with the endpoint being the development of hypertension. During the follow-up, hypertension developed in 1,168 subjects (74.1 per 1,000 person-years). The incidence of hypertension was higher in subjects who had obesity (106.2 vs. 67.8), dyslipidemia (96.1 vs. 69.0), high normal blood pressure (166.0 vs. 40.1), or impaired glucose tolerance (130.5 vs. 65.3 per 1,000 person-years) than in those without these disorders at baseline. The risk of hypertension was increased as the number of metabolic disorders in an individual increased. Multiple regression analysis indicated that obesity, high normal blood pressure, and impaired glucose tolerance remained independent predictors of the onset of hypertension. Thus, the presence of individual components of the metabolic syndrome predicts the development of hypertension. Prediction of the development of hypertension may lead to effective prevention of both hypertension and resulting cardiovascular diseases.
Hypertension Research 04/2008; 31(4):665-71. · 2.58 Impact Factor
