Achievement rate of target blood pressure in patients with hypertension treated by hypertension specialists and non-specialists in a real-world setting

Hypertension remains a major global healthcare issue. Considering that most Japanese patients with hypertension are managed by general practitioners, hypertension specialists should be involved in actual clinical practice. We investigated the blood pressure (BP), guidelines recommended for achievement rate of the target BP, and clinical variables of patients with hypertension treated by hypertension specialists and those treated by non-specialists in a real-world setting. Factors associated with the target BP achievement in this population were also investigated. Outpatients with hypertension from 12 medical facilities in Okinawa Prefecture were enrolled (n = 1469 [specialist group, 794; non-specialist group, 675]; mean age, 64.2 years; females, 45.8%). For all patients, BP and rate of the target BP achievement were 129.0 ± 15.5/74.6 ± 10.6 mmHg, and 51.8%, respectively. BP and the rate of target of BP achievement were 128.0 ± 15.1/73.4 ± 10.4 mmHg and 56.7% in the specialist group, and they were 130.1 ± 15.9/76.0 ± 10.8 mmHg and 46.1% in the non-specialist group. The urinary salt excretion and obesity rates were comparable between the specialist and non-specialist groups. Multivariable logistic analyses indicated that hypertension specialists and good medication adherence were positive factors, whereas obesity, chronic kidney disease, diabetes mellitus, and urinary salt excretion were inverse factors associated with target BP achievement in this population. Initiatives for salt reduction, medication adherence, and proper obesity management are crucial to improving BP management in patients with hypertension. Hypertension specialists are expected to play an essential role in them. For all patients, the target blood pressure (BP) achievement rate were 51.8%. Hypertension specialists and good medication adherence were positive factors in achieving target BP; conversely, obesity, diabetes mellitus, chronic kidney disease, and high urinary salt excretion were inverse factors in achieving target BP among patients with hypertension.

Urate-lowering drugs for chronic kidney disease with asymptomatic hyperuricemia and hypertension: a randomized trial

INTRODUCTION

Xanthine oxidase (XO) inhibitors may slow down chronic kidney disease (CKD) progression. The comparative effectiveness of the different urate-lowering drugs is unknown. The aim of this study was to determine whether urate-lowering therapy with an XO inhibitor (febuxostat) and that with a uricosuric drug (benzbromarone) are comparable in slowing renal function decline in patients with CKD complicated with hypertension and hyperuricemia.

METHODS

This study was an open-label randomized parallel-group clinical trial of 95 patients with stage G3 CKD in Japan. The patients had hypertension and hyperuricemia without a history of gout. They were randomized to receive febuxostat ( n  = 47; febuxostat group) or benzbromarone ( n  = 48; benzbromarone group) and titrated to reduce their serum urate level to <6.0 mg/dl. The primary end-point was change in estimated glomerular filtration rate (eGFR) from baseline to 52 weeks. The secondary end-points included changes in uric acid level, blood pressure, urinary albumin-to-creatinine ratio, and XO activity.

RESULTS

Of the 95 patients, 88 (92.6%) completed the trial. There were no significant differences in change in eGFR (in ml/min/1.73 m 2 ) between the febuxostat [-0.23, 95% confidence interval (CI), -2.00 to 1.55] and benzbromarone (-2.18, 95% CI, -3.84 to -0.52) groups (difference, 1.95; 95% CI, -0.48 to 4.38; P  = 0.115) nor in the secondary end-points, except for XO activity. Febuxostat significantly reduced XO activity ( P  = 0.010). There were no significant differences in primary and secondary outcomes between the groups. A decrease in eGFR was significantly less in the febuxostat group than that of the benzbromarone group in the CKDG3a, but not in CKDG3b, in the subgroup analysis. There were no adverse effects specific to either drug.

CONCLUSIONS

No significant differences were found in the effects of febuxostat and benzbromarone in renal function decline in stage G3 CKD complicated with hyperuricemia and hypertension.

Strategies for improving the treatment and control of hypertension in Japan

Despite the significant advancements in the diagnosis and treatment of hypertension, the burden of hypertension remains a major global health care concern. In Japan, estimates show that more than two-thirds of the population have uncontrolled hypertension, regardless of whether they were taking antihypertensive medication. To improve hypertension management, hypertension guidelines have been developed and updated regularly by hypertension societies across various countries and regions. The Japanese Society of Hypertension (JSH) updated the Guidelines for the Management of Hypertension in 2019 (JSH 2019). The JSH 2019 aims to establish a standard management strategy for hypertension and provide evidence to all health care providers. One of its updated main features is its proposal for multidisciplinary team-based care (TBC) involving physicians, pharmacists, nurses, dietitians, and other health care providers. The TBC will help initiate and intensify the management of hypertension, as well as combat clinical inertia, which is expected to contribute to uncontrolled blood pressure and subsequent development of cardiovascular diseases. This is consistent with the recommendations from recent major guidelines on hypertension management. Moreover, to reduce the evidence-practice gap in hypertension management, it is essential to disseminate the essence of the guidelines and provide hypertension education programs for all health care providers and patients. This review summarizes the points of the JSH 2019-based strategy for improving hypertension management and discusses guidelines for its implementation into actual clinical practice.

Effect of Nutrition Education on the Vegetable Intake of Residents in Okinawa

Background: Increasing vegetable intake is recommended for promoting health in communities. This study investigated the effects of nutrition education on vegetable intake and the factors associated with changes in vegetable intake among residents of Okinawa.

Methods and Results: Subjects (n=1,345; mean [±SD] age 56.8±14.6 years; 40.5% male) were recruited from among local residents participating in the Yui Kenko Project. Subjects completed the brief-type self-administered diet history questionnaire (BDHQ) and questionnaires on socioeconomic demographics and social capital. Subjects were divided into 2 groups according to residential area, namely south Okinawa (n=679), where local health promotion activities have been undertaken since the early 2000s, and central Okinawa (n=666). Survey results were fed back to each subject, and health lectures were then conducted at local community centers. After 1 year, the BDHQ was repeated to investigate changes in vegetable and nutritional parameters. After the intervention, residents of south Okinawa increased their crude and energy-adjusted vegetable intake (P<0.05), whereas residents of central Okinawa showed decreased vegetable intake (P<0.05). Univariable and multivariable regression models indicated that, in south Okinawa, participation in local health promotion activities and agreement with general trust were positively correlated with changes in energy-adjusted vegetable intake, whereas in central Okinawa no correlations were observed.

Conclusions: The status of social capital should be taken into account when implementing initiatives to increase vegetable intake in communities.

Optimal blood pressure target to prevent severe hypertension in pregnancy: A systematic review and meta-analysis

Severe hypertension in pregnancy is a hypertensive crisis that requires urgent and intensive care due to its high maternal and fetal mortality. However, there is still a conflict of opinion on the recommendations of antihypertensive therapy. This study aimed to identify the optimal blood pressure (BP) levels to prevent severe hypertension in pregnant women with nonsevere hypertension. Ovid MEDLINE and the Cochrane Library were searched, and only randomized controlled trials (RCTs) were included if they compared the effects of antihypertensive drugs and placebo/no treatment or more intensive and less intensive BP-lowering treatments in nonsevere hypertensive pregnant patients. A random effects model meta-analysis was performed to estimate the pooled risk ratio (RR) for the outcomes. Forty RCTs with 6355 patients were included in the study. BP-lowering treatment significantly prevented severe hypertension (RR, 0.46; 95% CI, 0.37-0.56), preeclampsia (RR, 0.82; 95% CI, 0.69-0.98), severe preeclampsia (RR, 0.38; 95% CI, 0.17-0.84), placental abruption (RR, 0.52; 95% CI, 0.32-0.86), and preterm birth (< 37 weeks; RR, 0.81; 95% CI, 0.71-0.93), while the risk of small for gestational age infants was increased (RR, 1.25; 95% CI, 1.02-1.54). An achieved systolic blood pressure (SBP) of < 130 mmHg reduced the risk of severe hypertension to nearly one-third compared with an SBP of ≥ 140 mmHg, with a significant interaction of the BP levels achieved with BP-lowering therapy. There was no significant interaction between the subtypes of hypertensive disorders of pregnancy and BP-lowering treatment, except for placental abruption. BP-lowering treatment aimed at an SBP < 130 mmHg and accompanied by the careful monitoring of fetal growth might be recommended to prevent severe hypertension.

Factors Associated with Nonachievement of Target Blood Pressure in Patients on Antithrombotic Therapy: A Real-World Study

Introduction:

The current guidelines for managing hypertension recommend strict blood pressure (BP) control to prevent bleeding complications in patients with hypertension on antithrombotic therapy. However, the target BP value of <130/80 mmHg is achieved in a small proportion of these patients. This study aimed to examine the factors associated with nonachievement of target BP value (≥130/80 mmHg) in patients on antithrombotic therapy.

Methods:

This retrospective study was conducted at an outpatient clinic in 2018. Clinical parameters were obtained from the center’s electronic medical database. Office BP was measured once in the sitting position. A target BP value of <130/80 mmHg was defined according to the Japanese Society of Hypertension Guidelines for the Management of Hypertension 2019.

Results:

Of the 26,803 outpatients who had scheduled visits during this time, 2,427 received antithrombotic therapy. Patients with chronic kidney disease stage 5 or on hemodialysis and those with missing data on body mass index were excluded from the study; eventually, 2,201 outpatients met the inclusion criteria. BP values of <140/90 mmHg were observed in 59.2% of these outpatients; however, only 30.6% displayed the target BP value of <130/80 mmHg. Univariate and multivariate logistic regression analyses indicated that male gender and obesity significantly correlated with nonachievement of the target BP (≥130/80 mmHg). However, heart failure and ischemic heart disease were negatively but significantly related to nonachievement of the target BP.

Conclusions:

The target BP value was achieved in only a small proportion of the patients treated with antithrombotic drugs. In patients on antithrombotic therapy, obesity appeared to be a modifiable risk factor, whereas cardiovascular comorbidities, such as heart failure, were negative factors contributing to nonachievement of the target BP.

Salt and potassium intake evaluated with spot urine and brief questionnaires in combination with blood pressure control status in hypertensive outpatients in a real-world setting

Reducing salt and increasing potassium intake are recommended lifestyle modifications for patients with hypertension. The estimated 24-h urinary salt excretion value from spot urine using Tanaka's formula and the salt check-sheet scores, questionnaire-based scores of salt intake, are practical indices of daily salt intake. However, few studies have evaluated salt intake with these methods in hypertensive outpatients. We examined salt and potassium intake with the spot urine method and the salt check-sheet scores of hypertensive outpatients in a multi-facility, real-world setting and examined whether the salt or potassium intake evaluated with these methods related to inadequate blood pressure control. Hypertensive outpatients from 12 medical facilities in the Okinawa prefecture were enrolled from November 2011 to April 2014 (n = 1559, mean age 63.9 years, 46% women). The mean blood pressure, urinary salt excretion value, urinary potassium excretion value, and total score on the salt check-sheet were 129/75 mmHg, 8.7 g/day, 1.6 g/day, and 10.4 points, respectively. The urinary salt excretion value and total score on the salt check-sheet but not urinary potassium excretion value were associated with inadequate blood pressure control (≥140/90 mmHg). Higher body mass index, estimated glomerular filtration rate, urinary potassium excretion value, total score on the salt check-sheet, and presence of inadequate blood pressure control were associated with high urinary salt excretion (≥10.2 g/day). In conclusion, hypertensive outpatients with high urinary salt excretion values estimated using Tanaka's formula or with high scores on the salt check sheet may be candidates for more intensive salt reduction guidance.

Investigation of Blood Pressure Control in Hypertensive Patients with and without Antithrombotic Therapy in a Real-World Setting

Background Although numerous studies have demonstrated a strong association between blood pressure (BP) and hemorrhagic complications of antithrombotic therapy, there is still a paucity of information regarding the status of BP control in hypertensive patients on antithrombotic therapy. Methods This cross-sectional, retrospective study was conducted at an outpatient clinic to examine BP control and its associated factors in hypertensive patients receiving or not receiving antithrombotic therapy. Results Of 26,803 outpatients who had scheduled visits in 2018, 7,800 hypertensive patients met the inclusion criteria, of whom 1,727 cases were on oral antithrombotic drugs. Then, target BP values were defined according to the Japanese Society of Hypertension Guidelines for the Management of Hypertension 2019. While BP values <140/90 mmHg were observed in 63.0% and 61.6% of patients with and without antithrombotic therapy, respectively, only 31.1% and 23.4% of them displayed BP values <130/80 mmHg. Multivariable logistic analysis indicated that comorbidity with obesity was a significant correlate of insufficient BP control (target BP <130/80 mmHg) in hypertensive patients, irrespective of antithrombotic therapy (patients with antithrombotic therapy, odds ratio (OR) = 1.690, 95% confidence interval (CI) = 1.351-2.113; patients without antithrombotic therapy, OR = 1.475, 95% CI = 1.290-1.687). Conclusion The majority of patients exhibited BP values <140/90 mmHg, whereas BP values <130/80 mmHg were achieved only in a small proportion of the patients. Furthermore, obesity appeared to be one of the factors contributing to insufficient BP control in a real-world setting.

Effect of Mineralocorticoid Receptor Blockade on Arterial Stiffness and Endothelial Function: A Meta-Analysis of Randomized Trials

Although numerous studies have confirmed the beneficial effects of pharmacological therapy for arterial stiffness and endothelial dysfunction, which are predictors/therapeutic targets for cardiovascular diseases, only a few overall quantitative evaluations of MRAs (mineralocorticoid receptor antagonists) exist. We searched PubMed and Cochrane CENTRAL (Cochrane Central Register of Controlled Trials) for randomized trials evaluating MRA effects on arterial stiffness measured by pulse wave velocity (PWV) or augmentation index and endothelial function measured by flow-mediated dilation. Data from the included trials were pooled by using random-effects meta-analysis of the weighted mean difference (MD) between the comparator groups. The primary outcome was the MD of PWV. In 11 trials including 515 patients, the MRA treatment reduced the PWV when compared with control (MD, -0.75 m/s [95% CI, -1.12 to -0.39], P<0.00001), without heterogeneity. There were comparable effects of MRA on carotid-femoral PWV and those on other forms of PWV (P=0.705 for heterogeneity). The effects of MRA on PWV were independent of blood pressure reduction related to the treatment according to meta-regression analysis. The MRA treatment reduced the augmentation index compared with control in 5 trials including 283 patients (MD, -6.74% [95% CI, -10.26 to -3.21], P=0.0002) and increased the flow-mediated dilation in 11 trials including 570 patients (MD, 1.18% [95% CI, 0.14 to 2.23], P=0.03). In conclusion, the current meta-analysis demonstrates the beneficial effects of MRA on PWV, augmentation index, and flow-mediated dilation.

Validation of preferred salt concentration in soup based on a randomized blinded experiment in multiple regions in Japan-influence of umami (L-glutamate) on saltiness and palatability of low-salt solutions

Sodium reduction is an important public health goal. Individual and population approaches are necessary for reducing the sodium content of processed foods and meals. The aim of the present study is to affirm the effect of monosodium l-glutamate (MSG), an umami substance, on the saltiness or palatability of low-salt solutions and to explore the preferred salt concentration in soup. Five hundred and eighty-four healthy participants from nineteen regions in Japan tasted 0.3, 0.6, and 0.9% NaCl solutions with or without 0.3% MSG. Evaluations of saltiness and palatability for each solution were conducted using a visual analog scale in a double-blinded randomized manner. Saltiness gradually increased depending on the concentration of NaCl. The saltiness of the 0.3% NaCl solution with MSG was rated significantly higher than that without MSG. The palatability ratings were higher for the solutions with MSG than for those without MSG for all NaCl concentrations. In particular, the palatability rating of the 0.3% NaCl solution with MSG was twice as high as that without MSG and was significantly higher than that of the other five test solutions. Furthermore, these results were observed to be approximately the same, irrespective of sex, age, region, etc. Salt reduction is believed to result in a loss of palatability. However, our results suggest that umami can compensate for the loss of palatability caused by salt reduction and that the addition of an appropriate amount of an umami substance can facilitate salt reduction from 0.9 to 0.3% without sacrificing palatability.

Optimal blood pressure targets for patients with hypertension: a systematic review and meta-analysis

Optimal blood pressure (BP) targets for hypertension have been an important clinical issue but have been elusive. The Systolic Blood Pressure Intervention Trial (SPRINT) showed significant benefits of intensive BP-lowering treatment with a target systolic BP level of < 120 mm Hg on major cardiovascular (CV) events and mortality, whereas there was a modest increase in renal events related to BP-lowering treatment. We searched the PubMed, Cochrane CENTRAL, and ICHUSHI databases for randomized trials that assigned participants to intensive versus usual BP-lowering treatment with different BP targets. The outcomes were major CV events, all-cause death, myocardial infarction, stroke, heart failure, renal events, and adverse events. Nineteen trials that enrolled a total of 55,529 participants with a mean follow-up duration ranging from 1.6 to 12.2 years were included in the present analysis. There was a significant reduction in major CV events, myocardial infarction, and stroke and a trend toward a reduction in heart failure associated with intensive BP-lowering treatment, but no differences in the risks of all-cause death, renal events, or adverse events were observed between the randomized groups. Subgroup analyses indicated that intensive BP-lowering treatment with a target of < 130/80 mm Hg and/or achievement of BP < 130/80 mm Hg were associated with a significant reduction in major CV events compared with the usual group. In conclusion, intensive BP-lowering treatment reduces the risk of CV events. A target BP level of < 130/80 mm Hg appears to be optimal for CV protection in patients with hypertension.

Responsiveness of α2-adrenoceptor/I1-imidazoline receptor in the rostral ventrolateral medulla to cardiovascular regulation is enhanced in conscious spontaneously hypertensive rat

Stimulation of α2-adrenoceptor/I1-imidazoline receptors in the rostral ventrolateral medulla decreases the blood pressure via sympathoinhibition. However, alteration of receptor responses in genetically hypertensive rats remains unclear. We examined cardiovascular responses of α2-adrenoceptor/I1-imidazoline receptor agonist and antagonists microinjected into the rostral ventrolateral medulla of conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. Injection of 2-nmol clonidine-an α2-adrenoceptor/I1-imidazoline receptor agonist-unilaterally into the rostral ventrolateral medulla decreased the blood pressure, heart rate, and renal sympathetic nerve activity; the responses were significantly enhanced in spontaneously hypertensive rats than in Wistar Kyoto rats. Co-injection of 2-nmol 2-methoxyidazoxan (a selective α2-adrenoceptor antagonist) or 2-nmol efaroxan (an I1-receptor antagonist) with 2 nmol of clonidine attenuated the hypotensive and bradycardic effects of clonidine-only injection. Injection of 2-methoxyidazoxan alone increased the blood pressure and heart rate in spontaneously hypertensive rats, but not in Wistar Kyoto rats. These results suggest enhanced responsiveness of α2-adrenoceptor/I1-imidazoline receptors in the rostral ventrolateral medulla of spontaneously hypertensive rats.

Differences in 24-h blood pressure profile of Japanese hypertensive patients under ARB treatment

Blood pressure (BP) control throughout the entire day is recommended for cardiovascular protection. Angiotensin-II receptor blockers (ARBs) are widely used in hypertensive patients because of beneficial class effects. It is uncertain, however, whether are there any differences in 24-h BP profiles among ARBs. We examined ambulatory blood pressure monitoring (ABPM) among 211 Japanese hypertensive patients (age, 69.4 ± 9.6 years; female, 59.2%) under treatment with five different ARBs. Patients were divided into five groups according to ARBs prescribed. Patient backgrounds were almost identical in all the groups and there were no differences in office, 24-h and daytime BP; however, nighttime BP with olmesartan was significantly lower than with other ARBs. Office BPs with candesartan and telmisartan, but not other ARBs, correlated well with 24-h BP (p < 0.01). Also, there were higher correlations between daytime and nighttime BP with candesartan and telmisartan. In all patients, pulse pressure with office BP was significantly correlated with ambulatory arterial stiffness index (p = 0.001) and fluctuation of systolic BP on ABPM (p = 0.002). In conclusion, different ARB treatments produced meaningful differences in 24-h profiles.

Interrelationship between brachial artery function and renal small artery sclerosis in chronic kidney disease

Chronic kidney disease (CKD), characterized by senile inflammation, is a risk factor for cardiovascular disease. Conduit artery function and small artery structure relate to cardiovascular disease. We examined the correlations, determinants and interrelationships of arterial indices in association with CKD in a cross-sectional study of 139 patients (60% male; mean age 44 years) with CKD (stages 3-5, 39%) who underwent a renal biopsy. Conduit artery function and small artery sclerosis were assessed by brachial artery flow-mediated dilatation (FMD) and semiquantitative evaluation of small artery intimal thickening (SA-IT), respectively. The estimated glomerular filtration rate correlated with FMD (r=0.31, P=0.0002) and inversely correlated with SA-IT (r=-0.54, P<0.0001). Multiple regression analysis showed that FMD was inversely correlated with SA-IT and vice versa. In addition, high-sensitivity C-reactive protein (hs-CRP) was significantly correlated with SA-IT, but not FMD. Multiple logistic analysis revealed that higher hs-CRP concomitant with decreased FMD was further associated with the risk of severe SA-IT compared with their individual effects. These findings suggest that both conduit artery and small artery disease develop with mutual interaction in parallel with decreased kidney function. Coexistence of inflammation and conduit artery dysfunction may be closely related to renal small artery sclerosis in patients with CKD.

The brain renin-angiotensin system and cardiovascular responses to stress: insights from transgenic rats with low brain angiotensinogen

The renin-angiotensin system (RAS) has been identified as an attractive target for the treatment of stress-induced cardiovascular disorders. The effects of angiotensin (ANG) peptides during stress responses likely result from an integration of actions by circulating peptides and brain peptides derived from neuronal and glial sources. The present review focuses on the contribution of endogenous brain ANG peptides to pathways involved in cardiovascular responses to stressors. During a variety of forms of stress, neuronal pathways in forebrain areas containing ANG II or ANG-(1-7) are activated to stimulate descending angiotensinergic pathways that increase sympathetic outflow to increase blood pressure. We provide evidence that glia-derived ANG peptides influence brain AT(1) receptors. This appears to result in modulation of the responsiveness of the neuronal pathways activated during stressors that elevate circulating ANG peptides to activate brain pathways involving descending hypothalamic projections. It is well established that increased cardiovascular reactivity to stress is a significant predictor of hypertension and other cardiovascular diseases. This review highlights the importance of understanding the impact of RAS components from the circulation, neurons, and glia on the integration of cardiovascular responses to stressors.

An association between uric acid levels and renal arteriolopathy in chronic kidney disease: a biopsy-based study

Uric acid (UA) can induce renal arteriolopathy in animal models. Whether there is an association between UA and renal arteriolopathy in patients with chronic kidney disease (CKD) is unknown. Here, we examined the cross-sectional association of serum UA levels with renal arteriolar hyalinosis and wall thickening. Arteriolar parameters were assessed by semiquantitative grading (max: grade 3) of arterioles in 167 patients with CKD (mean age, 42.4 years; 86 men and 81 women) who underwent renal biopsy. The mean serum UA level was 6.4 mg dl(-1). We observed hyalinosis in 94 patients (56%) and wall thickening in 119 patients (71%). As the UA level tertile increased, the proportion of higher-grade (grade 2 and 3) hyalinosis and wall thickening increased (hyalinosis, P<0.0001 and wall thickening, P=0.0002, for trend). Multiple logistic analysis adjusted for age ≥40 years, sex, hypertension status, diabetes mellitus status and estimated glomerular filtration rate <60 ml min(-1) per 1.73 m(2) showed that hyperuricemia (UA ≥7 mg dl(-1)) was significantly associated with a higher risk of hyalinosis (adjusted odds ratio: 3.13; 95% confidence interval: 1.23-7.94; P=0.02) and higher-grade (equal to or higher than the mean value) wall thickening (adjusted odds ratio: 2.66; 95% confidence interval: 1.11-6.38; P=0.03). Hence, these results suggest that hyperuricemia may be related to renal arteriolar damage in patients with CKD.

Abstract 83: Intracerebroventricular Administration of Autologous Bone Marrow-derived Cells Attenuate Slow Pressor Angiotensin II Initiated Hypertension in Rats

Objectives: Subcutaneous infusion of non-pressor doses of angiotensin II (Ang II) gradually produces hypertension in part via central mechanism. Bone marrow-derived cells (BMC) have an ability to secrete paracrine factors leading to improvements in tissue injury. We hypothesized that implantation of autologous BMCs in the brain would attenuate Ang II initiated neurogenic hypertension via secreted paracrine factors.

METHODS: Sprague-Dawley rats were divided into following 4 groups: rats received vehicle infusion with intracerebroventricular (icv) administration of medium (V/M group, n=5); rats received vehicle infusion with icv administration of DiI labeled BMCs (V/B group, n=3); rats received Ang II infusion (150 ng/kg/min) with icv administration of medium (A/M group, n=4); rats received Ang II infusion with icv administration of BMCs (A/B group, n=5). Three weeks following initiation of the infusion, rats had surgery to implant arterial and venous catheters. Resting mean arterial pressure (MAP) of rats was recorded in conscious unrestrained state and resting sympathetic tone was evaluated with a peak depressor response produced by hexamethonium (C6) injection.

Results: Systolic blood pressure (SBP) measured by tailcuff method was similar among the groups, only A/M group had a trend to increase in SBP. Resting MAPs of V/M, V/B, A/M and A/B group were 125±2, 116±2, 174±7, 134±8 mmHg, respectively. Ang II infusion significantly increased MAP in A/M group, however in A/B group, icv administration of BMCs attenuated the Ang II mediated increase in MAP. Heart rate was similar among the groups. The peak depressor responses to C6 injection in V/M, V/B, A/M and A/B group were 38±3, 46±6, 77±5, 48±1 mmHg, respectively. Ang II infusion significantly increased the peak depressor response to C6 and icv administration of BMCs attenuated the increase in peak depressor response. DiI positive cells were distributed to the choroid plexus, surface of ventricle, and subventricular zone but not to the subfornical organ.

Conclusion: Icv administration of autologous BMCs attenuate slow pressor Ang II initiated hypertension via attenuating the Ang II mediated sympathetic activation in rats. Paracrine factors secreted from the BMCs may be involved in this process.

Switching therapy from variable-dose multiple pill to fixed-dose single-pill combinations of angiotensin II receptor blockers and thiazides for hypertension

The efficacy and tolerability of switching therapy from free combinations of angiotensin II receptor blocker (ARB) and thiazide (A/T) to a fixed-dose of losartan and hydrochlorothiazide (L/H) has not been evaluated in Japan. We examined effects of switching therapy from variable-dose multiple-pill A/T to a fixed-dose L/H on blood pressure (BP) along with medication adherence and the degree of satisfaction in 91 hypertensive outpatients (mean age, 65.2 ± 9.6 years). After 6 months, a significant BP reduction (132 ± 9/76 ± 10 vs. 126 ± 12/72 ± 11 mm Hg), along with an improvement of attaining target BP (44.0 vs. 61.5%) and that of adherence, were observed. The magnitude of BP reduction in the participants increased their degree of satisfaction more significantly than in the participants who worsened their degree of satisfaction. The estimated glomerular filtration rate and the serum uric acid (UA) level decreased slightly but significantly. The hemoglobin A1c of participants with diabetes mellitus increased slightly but significantly. In conclusion, a switch in therapy from variable-dose, multiple-pill A/T combinations to a fixed-dose, single-pill L/H was effective in decreasing BP and serum UA in Japanese clinical practice. Metabolic side effects of L/H in patients with diabetes mellitus remain to be investigated.

Pioglitazone, a thiazolidinedione derivative, attenuates left ventricular hypertrophy and fibrosis in salt-sensitive hypertension

Thiazolidinediones, which stimulate peroxisome proliferator-activated receptor gamma, have been shown to prevent cardiovascular injury. However, little is known about their effects on salt-sensitive hypertension. We thus investigated whether or not pioglitazone affects left ventricular (LV) hypertrophy in Dahl salt-sensitive rats, then compared its effects to those of an angiotensin II receptor blocker, candesartan. Rats were used at 16 weeks of age after they had been fed either a low-salt (0.3%; DSL) or high-salt (8%; DSH) diet for 10 weeks; some of the DSH rats were treated with pioglitazone (10 mg/kg/day) or candesartan (4 mg/kg/day). Both drugs decreased the elevated blood pressure in DSH rats, although it was still higher than in DSL rats. Both drugs decreased plasma insulin levels, but neither affected plasma glucose levels. The thiobarbituric acid reactive substance level in the LV was decreased by both drugs. LV hypertrophy evaluated by echocardiography in DSH rats was nearly normalized by both drugs, whereas only candesartan decreased LV diameter. In histological analysis, both drugs ameliorated LV fibrosis and myocardial cell hypertrophy. Both drugs decreased elevated gene expression levels of transforming growth factor-beta1 and collagen type I, although the pioglitazone action was slightly modest. The metalloproteinase activity was increased in DSH rats, but both drugs decreased this level. Taken together, these findings indicate that pioglitazone reduced LV hypertrophy and fibrosis in salt-sensitive hypertension. Improvement in blood pressure, insulin level, and oxidative stress may be associated with this beneficial action of pioglitazone.

Modulation of reflex function by endogenous angiotensins in older transgenic rats with low glial angiotensinogen

Age-related impairments in baroreflex sensitivity in Sprague-Dawley rats are associated with low solitary tract nucleus content of angiotensin-(1-7). However, transgenic rats with low-brain angiotensinogen resulting from glial overexpression of an antisense oligonucleotide to angiotensinogen (ASrAOGEN) are spared age-related declines in cardiovascular function characteristic of Sprague-Dawley rats. We examine whether cardiovascular and reflex actions of angiotensin-(1-7) persist in the solitary tract nucleus of older (16 to 22 months) ASrAOGEN rats. Baroreflex sensitivity for control of heart rate and chemosensitive vagal afferent activation in response to phenylbiguanide were measured before and after bilateral microinjection of the angiotensin II type 1 receptor antagonist candesartan and angiotensin-(1-7) receptor antagonist (D-Ala(7))-angiotensin-(1-7) in urethane/chloralose-anesthetized rats. In older anesthetized ASrAOGEN rats, candesartan had no effect, whereas (D-Ala(7))-angiotensin-(1-7) significantly reduced baroreflex sensitivity (1.80+/-0.43 versus 0.50+/-0.17 ms/mm Hg). Phenylbiguanide responses were attenuated by injection of candesartan (-79+/-6 versus -55+/-12 mm Hg and -277+/-12 versus -156+/-27 bpm; P<0.05). In addition, resting blood pressure was reduced by injection of candesartan or (D-Ala(7))-angiotensin-(1-7). Within the solitary tract nucleus of older ASrAOGEN rats, it appears that glial angiotensinogen is the main source of angiotensin II attenuation of baroreflex sensitivity; endogenous angiotensin-(1-7) from nonglial sources enhances baroreflex sensitivity; nonglial sources of angiotensin II contribute to chemosensitive vagal afferent activation; and receptors for both peptides modulate resting arterial pressure under anesthesia. These results suggest a novel mechanism for the preservation of baroreflex sensitivity during aging.

Azelnidipine Attenuates Cardiovascular and Sympathetic Responses to Air-Jet Stress in Genetically Hypertensive Rats

Azelnidipine is a new dihydropyridine calcium channel blocker that causes minimal stimulation of the sympathetic nervous system despite its significant depressor effect. In the present study, we examined the effects of oral or intravenous administration of azelnidipine on cardiovascular and renal sympathetic nerve activity (RSNA) responses to air-jet stress in conscious, unrestrained stroke-prone spontaneously hypertensive rats. Oral administration of high-dose azelnidipine (10 mg/kg per day) or nicardipine (150 mg/kg per day) for 10 days caused a significant and comparable decrease in blood pressure, but low-dose azelnidipine (3 mg/kg per day) did not. Air-jet stress increased mean arterial pressure (MAP), heart rate (HR) and RSNA. High-dose azelnidipine significantly attenuated the increases in MAP, HR and RSNA in response to air-jet stress while nicardipine did not. Low-dose azelnidipine significantly attenuated the pressor response with a trend of decrease in RSNA. Intravenous injection of azelnidipine induced a slowly developing depressor effect. To obtain a similar time course of decrease in MAP by azelnidipine, nicardipine was continuously infused at adjusted doses. Both drugs increased HR and RSNA significantly, while the change in RSNA was smaller in the azelnidipine group. In addition, intravenous administration of azelnidipine attenuated the responses of MAP, HR, and RSNA to air-jet stress; by comparison, the inhibitory actions of nicardipine were weak. In conclusion, oral or intravenous administration of azelnidipine inhibited cardiovascular and sympathetic responses to air-jet stress. This action of azelnidipine may be mediated at least in part by the inhibition of the sympathetic nervous system.

Changes in the Demographics and Prevalence of Chronic Kidney Disease in Okinawa, Japan (1993 to 2003)

To compare the risk factor demographics and the prevalence of chronic kidney disease (CKD), we analyzed two databases from the 1993 (N=143,948) and 2003 (N=154,019) mass screenings in Okinawa, Japan (Okinawa General Health Maintenance Association registry). We estimated the glomerular filtration rate (GFR) using serum creatinine (SCr) levels. SCr was measured by the modified Jaffe method in 1993 and by enzyme assay in 2003; the relation between the two methods was: SCr (Jaffe) = 0.194 + 1.079 x SCr (enzyme). CKD prevalence was compared using the estimated GFR calculated by the abbreviated Modification of Diet in Renal Disease (MDRD) equation. SCr was measured in 66.2% (1993) and 69.8% (2003) of the total screenees. Proteinuria was present in 3.4% (1993) and 4.3% (2003) of the total screened population, respectively. The prevalence of CKD (GFR<60 ml/min/1.73 m(2)) was similar between the two databases, being 15.7% in 1993 and 15.1% in 2003. However, the demographics of the CKD risk factors changed during the study period. The mean level of systolic blood pressure decreased, whereas the prevalence of obesity and the mean levels of serum cholesterol and fasting plasma glucose increased. In 2003, the estimated prevalence of metabolic syndrome in the general population of Japan calculated using the modified National Cholesterol Education Program (NCEP) criteria was 19.1%. The prevalence of CKD was significantly associated with that of metabolic syndrome: the age- and sex-adjusted odds ratio was 1.332 (95% confidence interval [CI], 1.277-1.389; p<0.0001). In conclusion, the demographics of the participants of the general screenings in Okinawa, Japan differed between the 1993 and 2003 screenings, but the prevalence of CKD seemed to be similar, or at least did not increase substantially, between the two databases.

Baroreceptor reflex regulation in anesthetized transgenic rats with low glia-derived angiotensinogen

Endogenous angiotensin (ANG) II and ANG-(1-7) act at the nucleus tractus solitarius (NTS) to differentially modulate neural control of the circulation. The role of these peptides endogenous to NTS on cardiovascular reflex function was investigated in transgenic rats with low brain angiotensinogen (Aogen) due to glial overexpression of an antisense to Aogen (ASrAOGEN) and in Sprague-Dawley (SD) rats. Arterial baroreceptor reflex sensitivity (BRS) for control of heart rate (HR) in response to increases in mean arterial pressure (MAP) was tested before and after bilateral microinjection of the angiotensin type 1 (AT(1)) receptor blocker candesartan or the ANG-(1-7) receptor blocker (d-Ala(7))-ANG-(1-7) into the NTS of urethane-chloralose-anesthetized ASrAOGEN and SD rats. Baseline MAP was higher in ASrAOGEN than in SD rats under anesthesia (P < 0.01). Injection of candesartan or (d-Ala(7))-ANG-(1-7) decreased MAP (P < 0.01) and HR (P < 0.05) in ASrAOGEN, but not SD, rats. The BRS at baseline was similar in ASrAOGEN and SD rats. Candesartan increased BRS by 41% in SD rats (P < 0.01) but was without effect in ASrAOGEN rats. In contrast, the reduction in BRS after (d-Ala(7))-ANG-(1-7) administration was comparable in SD (31%) and ASrAOGEN rats (34%). These findings indicate that the absence of glia-derived Aogen is associated with 1) an increase in MAP under anesthesia mediated via AT(1) and ANG-(1-7) receptors within the NTS, 2) the absence of an endogenous ANG II contribution to tonic inhibition of BRS, and 3) a continued contribution of endogenous ANG-(1-7) to tonic enhancement of BRS.

Sympathetic hyperreactivity to air-jet stress in the chromosome 1 blood pressure quantitative trait locus congenic rats

A chromosome 1 blood pressure quantitative trait locus (QTL) was introgressed from the stroke-prone spontaneously hypertensive rats (SHRSP) to Wistar-Kyoto (WKY) rats. This congenic strain (WKYpch1.0) showed an exaggerated pressor response to both restraint and cold stress. In this study, we evaluated cardiovascular and sympathetic response to an air-jet stress and also examined the role of the brain renin-angiotensin system (RAS) in the stress response of WKYpch1.0. We measured mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) responses to air-jet stress in WKYpch1.0, WKY, and SHRSP. We also examined effects of intracerebroventricular administration of candesartan, an ANG II type 1 receptor blocker, on MAP and HR responses to air-jet stress. Baseline MAP in the WKYpch1.0 and WKY rats were comparable, while it was lower than that in SHRSP rats. Baseline HR did not differ among the strains. In WKYpch1.0, air-jet stress caused greater increase in MAP and RSNA than in WKY. The increase in RSNA was as large as that in SHRSP, whereas the increase in MAP was smaller than in SHRSP. Intracerebroventricular injection of a nondepressor dose of candesartan inhibited the stress-induced pressor response to a greater extent in WKYpch1.0 than in WKY. Intravenous injection of phenylephrine caused a presser effect comparable between WKYpch1.0 and WKY. These results suggest that the chromosome 1 blood pressure QTL congenic rat has a sympathetic hyperreactivity to an air-jet stress, which causes exaggerated pressor responses. The exaggerated response is at least partly mediated by the brain RAS.

Impaired heart rate baroreflex in older rats: role of endogenous angiotensin-(1-7) at the nucleus tractus solitarii

Age-related baroreflex reductions in function may originate from central neural dysregulation as well as vascular structural/functional changes. We determined the role of 2 angiotensin (Ang) peptides at the nucleus tractus solitarii in age-related baroreflex impairment. Baroreflex sensitivity control of heart rate in response to increases in blood pressure was tested in younger (3 to 5 months) and older (16 to 20 months) anesthetized male Sprague-Dawley rats before and after bilateral solitary tract injections of the Ang II type 1 (AT1) receptor antagonist candesartan (24 pmol) or the Ang-(1-7) antagonist (D-Ala7)-Ang-(1-7) (144 fmol or 24 pmol). Basal reflex sensitivity of older rats was significantly lower than younger rats. In younger rats, the reflex was facilitated by bilateral candesartan injections and attenuated by bilateral (D-Ala7)-Ang-(1-7) injections. In older rats, the reflex was facilitated by AT1 blockade; however, (D-Ala7)-Ang-(1-7) injected into the solitary tract nucleus had no effect. Neprilysin mRNA in the medulla was lower in older rats compared with younger rats, whereas angiotensin-converting enzyme (ACE), ACE2, and mas receptor mRNA levels of older rats did not differ from values of younger rats. Thus, opposing actions of endogenous Ang II and Ang-(1-7) in the solitary tract nucleus contribute to baroreflex function in response to increases in mean arterial pressure of younger rats. The attenuated counterbalancing effect of Ang-(1-7) on baroreflex function is lost in older rats, which may be attributable to diminished production of the peptide from neprilysin.

[Therapeutic strategy for morning blood pressure elevation in elderly hypertensives]

Although the cardiovascular events such as stroke, angina pectoris and myocardial infarction can occur at any time of day, it has been known that the peak incidence of the cardiovascular events increases during the morning period. In elderly hypertensives, a greater morning blood pressure surge is associated with an advanced silent cerebrovascular disease as well as a higher incidence of stroke. Thus, the blood pressure control of the early morning period may become an important therapeutic strategy for preventing the cardiovascular events. In this review, we focused on the recent strategy for morning blood pressure rising in the elderly hypertensives.

Severe abdominal pain associated with allergic reaction to nafamostat mesilate in a chronic hemodialysis patient

A 33-year-old woman was referred from an outside dialysis clinic to our hospital because of severe abdominal pain during hemodialysis. She had been on chronic hemodialysis for the past 11 years due to chronic glomerulonephritis. Nafamostat mesilate was used as an anticoagulant for hemodialysis, because it was during her menstrual period with hypermenorrhea. On admission, she had no abdominal pain or gynecological abnormalities. On the second day, she had similar abdominal pain during hemodialysis with nafamostat mesilate in our dialysis unit. The abdominal pain disappeared within 60 minutes after discontinuing the hemodialysis. We re-started dialysis using heparin instead of nafamostat mesilate and she had no symptoms. The titer of total immunoglobulin E was high. The drug lymphocyte stimulation test was positive for nafamostat mesilate and antigen specific immunoglobulin E to nafamostat mesilate was highly positive in her blood. Although an allergic reaction to nafamostat mesilate is a rare complication, it should be one of the differential diagnoses of abdominal pain occurring during hemodialysis.

Hypotensive and sedative effects of clonidine injected into the rostral ventrolateral medulla of conscious rats

We examined the effects of clonidine injected unilaterally into the rostral ventrolateral medulla (RVLM) of conscious, unrestrained rats. We also examined whether the local alpha(2)-adrenoceptor mechanism contributed to the action of clonidine injected into the RVLM. Injection of clonidine but not vehicle solution significantly decreased the mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) in conscious, unrestrained rats as well as in propofol-anesthetized rats. The frequency of natural behavior was significantly lower after clonidine injection than after vehicle injection. The depressor and sympathoinhibitory responses were significantly larger in the propofol-anesthetized rats than in the conscious rats. Coinjection of a selective alpha(2)-adrenoceptor antagonist, 2-methoxyidazoxan, with clonidine into the RVLM significantly attenuated the depressor, bradycardiac, sympathoinhibitory, and sedative effects of clonidine injected alone. In conclusion, clonidine injected into the RVLM decreased MAP, HR, and RSNA and caused sedation in conscious, unrestrained rats. The action of clonidine in the RVLM was at least partly mediated by alpha(2)-adrenoceptor mechanisms.

Cardiovascular and sympathetic effects of L-glutamate and glycine injected into the rostral ventrolateral medulla of conscious rats

The aim of the present study was to examine the effects of L-glutamate and glycine microinjected into the rostral ventrolateral medulla (RVLM) in conscious unrestrained rats. Microinjection of 2 nmol of L-glutamate increased the mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) in the conscious rats. The RSNA responses were significantly larger in the conscious rats than in anesthetized rats, while the magnitude of the pressor responses was similar in conscious and urethane-anesthetized rats. L-Glutamate injection significantly decreased heart rate in the conscious rats, whereas it increased the heart rate slightly but not significantly in the anesthetized rats. Microinjection of 100 nmol of glycine into the RVLM of conscious rat decreased MAP and RSNA. In 2 of the 6 rats examined, the depressor and sympathoinhibitory responses were preceded by a few seconds of a pressor and sympathoexcitatory phase. The decreases of RSNA in response to glycine injection were significantly larger in the conscious rats than in the anesthetized rats, whereas the magnitude of the depressor responses was similar in the two groups of rats. Heart rate decreased in response to glycine injection into the RVLM in the conscious and the anesthetized rats. In conclusion, in conscious unrestrained rats, as well as in urethane-anesthetized rats, L-glutamate acts as a sympathoexcitatory agent and glycine acts as a sympathoinhibitory agent in the RVLM. The sympathetic responses to these amino acids are larger in conscious rats than in anesthetized rats.

Ouabain-like immunoreactivity in the medulla oblongata of rats

An isomer of ouabain, the ouabain-like compound (OI,C), may participate in the regulation of body fluid volume and vascular tone. Forebrain regions, especially the hypothalamus, are reported to be sites of OLC action in the central nervous system. The medulla oblongata is another critical area involved in central cardiovascular regulation. We reported that the microinjection of either monoclonal antibody to ouabain T8B11 or Fab fragment of digoxin-specific antibody into the rostral ventrolateral medulla significantly decreased mean arterial pressure and renal sympathetic nerve activity in anesthetized normotensive rats (TERUYA et al.: J. Clin. Invest. 99: 2791-2798, 1997). Using T8B11, we examined the ouabain-like immunoreactivity in the medulla oblongata of normotensive rats. In periodate-lysine-paraformaldehyde fixed tissues, ouabain-like immunoreactive neurons were detected in the nuclei and regions in the medulla oblongata including the ventrolateral medulla, ventromedial medulla, nucleus ambiguus, caudal raphe nuclei, nucleus of solitary tract, and dorsal motor nucleus of the vagus. When an Fab fragment of digoxin-specific antibody was used as a first antibody, the digoxin-like immunoreactive neurons were distributed in almost the same pattern as those observed with the use of T8B11. In the brain fixed with the "three-step" procedure developed by YAMADA et al. (1987), which was used in a previous ouabain immunohistochemical study of the hypothalamus, ouabain-like immunoreactivity in the medulla oblongata was much weaker in intensity and less restricted in distribution than that in the hypothalamus. These findings suggest that ouabain-like immunoreactivities are present in the medulla oblongata with a manner of distribution different from that seen in the hypothalamus. Some ouabain-immunopositive nuclei and regions in the medulla oblongata, especially the rostral ventrolateral medulla, may be other OLC action sites.

Prolonged NOS inhibition in the brain elevates blood pressure in normotensive rats

Systemic inhibition of nitric oxide synthase (NOS) evokes hypertension, which is enhanced by salt loading, partly via augmented sympathetic activity. We investigated whether inhibition of brain NOS elevates blood pressure (BP) in normotensive rats and, if so, whether the BP elevation is enhanced by salt loading. After a 2-wk low-salt (0.3%) diet, male Sprague-Dawley (SD) rats were divided into four groups. Groups 1 and 2 received a chronic intracerebroventricular infusion of 0.5 mg . kg-1 . day-1 of NG-monomethyl-L-arginine (L-NMMA), and groups 3 and 4 were given artificial cerebrospinal fluid (aCSF). Groups 1 and 3 were placed on a high-salt (8%) diet, whereas groups 2 and 4 were on a low-salt diet. On day 9 or 10, group 1 showed significantly higher mean arterial pressure (MAP) in a conscious unrestrained state (129 +/- 3 mmHg vs. 114 +/- 3, 113 +/- 1, and 108 +/- 3 mmHg in groups 2, 3, and 4, respectively, P < 0.05). On a high-salt diet, response of renal sympathetic nerve activity but not of BP to air-jet stress was significantly larger in rats given L-NMMA than in rats given aCSF (29 +/- 4% vs. 19 +/- 3%, P < 0.05). When the intracerebroventricular infusions were continued for 3 wk, MAP was significantly higher in rats given L-NMMA than in rats given aCSF irrespective of salt intake, although the difference was approximately 7 mmHg. Thus chronic inhibition of NOS in the brain only slightly elevates BP in SD rats. Salt loading causes a more rapid rise in BP. The mechanisms of the BP elevation and its acceleration by salt loading remain to be elucidated.

Role of ouabain-like compound in the rostral ventrolateral medulla in rats

To determine whether ouabain-like compound (OLC) exerts modulatory influences on the activity of vasomotor neurons in the rostral ventrolateral medulla (RVLM), we examined the effects of microinjecting ouabain, digoxin-specific antibody Fab fragments, and mAb against ouabain on the rat RVLM. Microinjection of ouabain into the unilateral RVLM of anesthetized normotensive rats elicited dose-dependent increases in mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA). The pressor and sympathoexcitatory effects of ouabain in the RVLM were reversed by microinjections of an M2 muscarinic antagonist, gallamine, or digoxin-specific antibody Fab fragments. Furthermore, a prior microinjection in the RVLM of gallamine, digoxinspecific antibody Fab fragments, or kainic acid or intravenous injection of hexamethonium all prevented the pressor and sympathoexcitatory effects induced by a subsequent microinjection of ouabain. Microinjections of either digoxinspecific antibody Fab fragments or gallamine per se significantly decreased baseline MAP and RSNA. Injection of digoxin-specific antibody Fab fragments attenuated the effects of a subsequent injection of gallamine. Microinjection of mAb against ouabain, but not nonspecific IgG, also significantly decreased baseline MAP and RSNA. These results suggest that OLC in the RVLM contributes to the tonic activity of vasomotor neurons in anesthetized normotensive rats, and the action of OLC in the RVLM is at least partly mediated by M2 muscarinic mechanisms.