-374 T/A polymorphism in RAGE gene is associated with onset of diabetes mellitus, atherosclerosis, and renal dysfunction in patients with hypertension.

Receptor of advanced glycation end products (RAGE) is reportedly linked with chronic inflammatory diseases due to aging or diabetes. The aim of this study was to show how -374 T/A RAGE has an impact on systemic vascular damage and renal function. The study subjects were a total of 468 essential hypertension patients from the Non-Invasive Atherosclerotic Evaluation in Hypertension (NOAH) study cohort. We prospectively examined the association of -374 T/A RAGE with their prognoses and investigated the correlation between -374 T/A RAGE and multiple clinical parameters. Kaplan-Meier analysis did not show a significant association of -374 T/A RAGE with total mortality or the prevalence of cardiovascular events. Carriers of the A allele showed a significantly higher prevalence of diabetes mellitus (DM) and lower estimated glomerular filtration rate (eGFR) than subjects without this allele. In subjects with DM, carriers of the A allele showed a significantly lower eGFR. These significant correlations were only seen in male subjects. Carriers of the A allele of -374 T/A RAGE show an independent risk of atherosclerosis and reduced renal function in male hypertensive patients with DM.

Loss of ACE2 exaggerates high-calorie diet-induced insulin resistance by reduction of GLUT4 in mice.

ACE type 2 (ACE2) functions as a negative regulator of the renin-angiotensin system by cleaving angiotensin II (AII) into angiotensin 1-7 (A1-7). This study assessed the role of endogenous ACE2 in maintaining insulin sensitivity. Twelve-week-old male ACE2 knockout (ACE2KO) mice had normal insulin sensitivities when fed a standard diet. AII infusion or a high-fat, high-sucrose (HFHS) diet impaired glucose tolerance and insulin sensitivity more severely in ACE2KO mice than in their wild-type (WT) littermates. The strain difference in glucose tolerance was not eliminated by an AII receptor type 1 (AT1) blocker but was eradicated by A1-7 or an AT1 blocker combined with the A1-7 inhibitor (A779). The expression of GLUT4 and a transcriptional factor, myocyte enhancer factor (MEF) 2A, was dramatically reduced in the skeletal muscles of the standard diet-fed ACE2KO mice. The expression of GLUT4 and MEF2A was increased by A1-7 in ACE2KO mice and decreased by A779 in WT mice. A1-7 enhanced upregulation of MEF2A and GLUT4 during differentiation of myoblast cells. In conclusion, ACE2 protects against high-calorie diet-induced insulin resistance in mice. This mechanism may involve the transcriptional regulation of GLUT4 via an A1-7-dependent pathway.

The impact of visit-to-visit variability in blood pressure on renal function.

Hypertension is an important risk factor for cardiovascular diseases such as chronic kidney disease. It is still not fully understood how blood pressure impacts the kidneys. In this study, we aimed to establish the significance of visit-to-visit variability in blood pressure for renal function. We analyzed 143 consecutive patients undergoing renal Doppler ultrasonography in our hospital ward and measured blood pressure at outpatient visits six or more times. We analyzed the correlation between visit-to-visit variability in blood pressure and multiple clinical parameters, including albuminuria and resistive index evaluated by renal Doppler ultrasonography, which is thought to be a good indicator of renal vascular resistance. Subjects with higher variability in systolic blood pressure showed a significantly higher prevalence rate of clinical albuminuria and microalbuminuria, and showed significantly higher resistive index. Stepwise multiple regression analysis showed that variability in systolic blood pressure was a significant risk factor for higher resistive index, independent of other renal risk factors. Visit-to-visit variability in blood pressure correlates significantly with renal function and renal arteriosclerotic change. This parameter could provide additional information about renal arteriosclerotic change independent of estimated glomerular filtration rate and albuminuria, and should be considered a therapeutic target for renal protection.

The combination of chronic kidney disease and increased arterial stiffness is a predictor for stroke and cardiovascular disease in hypertensive patients.

To clarify the clinical utility of pulse wave velocity (PWV) and chronic kidney disease (CKD) in hypertension, we analyzed the prognostic impact of PWV and CKD on cerebrocardiovascular disease in hypertensive patients. This study consisted of 531 patients with essential hypertension (male/female=292/239, mean age=61.7±12.3, mean follow-up=7.0±3.0 years) and was performed between January 1998 and June 2004. We used questionnaires to assess stroke (n=57), cardiovascular diseases (CVDs; myocardial infarction, angina and congestive heart failure; n=44) and death (n=53) as primary end points. At baseline, we evaluated the carotid-femoral PWV (9.1±1.8 m s(-1)), the glomerular filtration rate and urinary protein excretions. We divided these subjects into those in the highest quartile of PWV and other subjects and into CKD (n=149) and non-CKD (n=458). We evaluated the prognostic influences of PWV and CKD with Kaplan-Meier analysis and Cox's proportional hazard model. PWV in CKD (9.6±1.9 m s(-1)) was higher than in non-CKD (8.8±1.6 m s(-1); P<0.0001), and creatinine was slightly decreased in the highest PWV group (1.09±0.35 mg dl(-1), P<0.0001). On the basis of Kaplan-Meier analysis, the highest PWV group (PWV>10.1 m s(-1); P=0.0003) and the CKD group (P=0.0005) showed significantly higher proportions of stroke and CVD events. In addition, the highest PWV group showed the highest percentage of stroke (P=0.0007), and the CKD group showed the highest proportion of CVD (P<00001). High PWV and CKD were independent predictors for stroke and CVD (P=0.0332) by Cox's proportional hazard model. These data suggest that increased aortic stiffness and CKD may be predictors for stroke and cardiovascular events in hypertensive patients.

Klotho protein diminishes endothelial apoptosis and senescence via a mitogen-activated kinase pathway.

AIM: Mice that carry the Klotho mutation (KL(-) (/) (-) ) manifest diverse age-related disorders similar to those observed in humans. Thus, the Klotho protein might function as an anti-aging hormone in mammals. Recently, we reported that Klotho recombinant protein attenuated apoptosis and cellular senescence in endothelial cells, but the mechanism remained unclear. Here, we designed an in vitro study to test whether inhibitors of extracellular signal-regulated kinase and mitogen-activated kinase kinase could affect Klotho regulation of apoptosis and cellular senescence. METHODS: Cellular senescence was investigated in human umbilical vein endothelial cells treated with or without Klotho recombinant protein, and with or without inhibitors of mitogen-activated kinases. Senescence was quantified by staining with senescence-associated ß-galactosidase and by evaluating western blots probed for phosphorylation of mitogen-activated kinases. Apoptosis was assayed on western probed for p53, p21, and caspase-3 and -9. RESULTS: The Klotho recombinant protein induced transient phosphorylation of mitogen-activated kinases within a few minutes. Application of inhibitors of mitogen-activated kinases attenuated the ability of Klotho to interfere with apoptosis and senescence in endothelial cells. CONCLUSION: This study demonstrated that Klotho attenuated cellular apoptosis and senescence in vascular cells via mitogen-activated kinase kinase and extracellular signal-regulated kinase pathways.

Usefulness of the resistive index in renal Doppler ultrasonography as an indicator of vascular damage in patients with risks of atherosclerosis.

BACKGROUND: Chronic kidney disease (CKD) is caused by various risk factors of cardiovascular disease (CVD). The estimated glomerular filtration rate (eGFR) is commonly used for the evaluation of the renal function in patients with CKD; however, it is difficult to assess the pathogenesis of CKD and predict the renal prognosis accurately using only eGFR. The resistive index (RI) in renal Doppler ultrasonography (RDU) is thought to be a good indicator of renal vascular resistance caused by atherosclerosis. In the present study, we investigated whether RI could be used to evaluate the pathogenesis of renal damage and predict the renal prognosis and investigated the correlation between RI and blood pressure (BP) fluctuations in patients with or without hypertension. METHODS: The total study population included 194 patients (mean age: 66.2 years), who underwent RDU in our hospital ward between February 2009 and July 2010. We investigated the correlation between RI and multiple clinical parameters, including ambulatory blood pressure monitoring (ABPM). RESULTS: RI significantly correlated with age, eGFR, diastolic BP, pulse pressure and level of albuminuria. Patients with diabetes mellitus (DM) showed a significantly higher RI than patients without DM, although their eGFR was similar; thus, DM might accelerate renal vascular damage and RI could detect earlier changes of vascular damage proceeding the time eGFR is reduced. Regarding ABPM, patients with a larger morning surge [systolic blood pressure (SBP) in the early morning--lowest SBP during sleep] showed a significantly higher RI. CONCLUSIONS: The present study indicated that RI might be very useful for the evaluation of very early renal damage more effectively than eGFR and that diurnal BP change might be partly due to the progression of atherosclerotic change in the kidney evaluated by RI.

Angiotensin-converting enzyme single nucleotide polymorphism is a genetic risk factor for cardiovascular disease: a cohort study of hypertensive patients.

The renin-angiotensin system (RAS) adversely affects stroke and cardiovascular disease; polymorphisms in genes involved in this system are associated with cardiovascular disease. The aim of the present study was to confirm the genetic risk of these polymorphisms for stroke and cardiovascular events in a cohort study of 515 hypertensive patients in Japan (follow-up period 90.6±30.2 months). The insertion/deletion (I/D) polymorphism of the gene encoding angiotensin-converting enzyme (ACE), the M235T amino acid change in angiotensinogen, and the A1166C polymorphism in angiotensin II type 1 receptor were determined by TaqMan PCR. In Kaplan-Meier analyses, the ACE I/D polymorphism was a risk factor for cerebro-cardiovascular events, especially cardiovascular events (P<0.0001), and the M235T mutation was a risk factor for cardiovascular events (P<0.0105). The cumulative rates of cerebro-cardiovascular end points for the ACE polymorphism were 10.6, 16.4 and 42.2% for the II (n=207), ID (n=244) and DD (n=64) genotype carriers, respectively (P<0.0001). Cox's proportional hazard models revealed that the ACE DD genotype was a risk factor for cerebro-cardiovascular and cardiovascular events (after adjusting for common risk factors), anti-hypertensive treatment and RAS inhibition (P<0.0001). Moreover, after adjustment for the common risk factors left ventricular hypertrophy and previous myocardial infarction/stroke, these phenomena were preserved. Thus, the DD genotype of ACE may be a genetic risk factor for cerebro-cardiovascular disease, especially cardiovascular events, in hypertensive patients in Japan.

ß-Adrenergic receptor gene polymorphism is a genetic risk factor for cardiovascular disease: a cohort study with hypertensive patients.

Single-nucleotide polymorphisms (SNPs) of the ß-adrenergic receptor (ßADR) subtypes are related to hypertension and obesity. This hospital-based cohort study with hypertensive patients evaluated five ßADR SNPs in association with cardiovascular events. The cohort included 357 hypertensive patients (male = 181; mean age = 61.5 ± 11.8 years) seen between January 1998 and June 2004. The SNPs (Ser49Gly and Arg389Gly for ß(1)ADR; Gly16Arg and Glu27Gln for ß(2)ADR; Trp64Arg for ß(3)ADR) were identified by PCR. We used Kaplan-Meier curves to assess the prognostic effect of these SNPs on cardiovascular disease (CVD). The SNP frequencies were Ser/Ser:Ser/Gly:Gly/Gly = 243:104:10; Arg/Arg:Arg/Gly:Gly/Gly = 256:95:6; Gly/Gly:Gly/Arg:Arg/Arg = 71:201:85; Gln/Gln:Glu/Gln = 308:49; and Trp/Trp:Trp/Arg:Arg/Arg = 265:89:3. A total of 17 stroke and 15 coronary artery disease cases were recorded. By Kaplan-Meier analysis, the Ser/Ser SNP in Ser49Gly (P = 0.0398), the Glu/Gln SNP in Glu27Gln (P = 0.0390) and the Trp/Trp SNP in Trp64Arg (P = 0.0132) were associated with lower event-free CVD survival (log-rank, Mantel-Cox model). A Cox proportional hazards model revealed that only the Trp/Trp SNP (P = 0.0321) and age (P = 0.0186) were independently related to lower event-free survival for CVD, adjusted for gender, diabetes, dyslipidemia, blood pressure, body mass index, medication and hypertensive complications. Combination Kaplan-Meier analysis of these three positive SNPs indicated a higher frequency of CVD among patients with the combination of Ser/Ser in Ser49Gly of ß(1), Glu/Gln in Glu27Gln of ß(2) and Trp/Trp in Trp64Arg of ß(3) (P = 0.0209). These three SNPs, especially the Trp64Arg SNP of ß(3)ADR, might be risk factors for CVD in hypertensive patients.

The counterregulating role of ACE2 and ACE2-mediated angiotensin 1-7 signaling against angiotensin II stimulation in vascular cells.

To clarify the role of endogenous angiotensin (Ang)-converting enzyme 2 (ACE2) and its cleavage product, Ang 1-7, in the atherogenic stimulation of vascular cells, we investigated the effect of pharmacological inhibition of ACE2 and Mas, an Ang 1-7 receptor, on cellular responses against Ang II stimulation. We measured extracellular signal-regulated kinase (ERK) 1/2 phosphorylation by western blot, smooth muscle cell (SMC) proliferation by WST assay and the adhesion of monocytes labeled with PKH67 to endothelial cells (ECs) by fluorescence microplate reader. Cells were pretreated with Ang 1-7, olmesartan (Ang II type 1 receptor (AT1) blocker), DX600 (ACE2 inhibitor), -Ala7-Ang1-7 (D-Ala; Mas antagonist), or combinations of treatments before the application of Ang II. Treatment with Ang II increased phosphorylated ERK 1/2 of SMC and EC, proliferation of SMC and adhesion of monocyte to EC, which were blocked by olmesartan. Pretreatment with DX600 either did not accelerate or only slightly accelerated these cellular responses. However, when Ang II signaling through AT1 was reduced by olmesartan, the additional treatment with DX600 significantly blunted some of the effect of olmesartan. Similarly, pretreatment with D-Ala reduced the inhibitory effect of olmesartan in response to Ang II stimulation. Endogenous ACE2 in vascular cells may contribute to counteracting the Ang II-mediated cellular response partly by upregulating the Ang 1-7 signaling through Mas.

Strong suppression of the renin-angiotensin system has a renal-protective effect in hypertensive patients: high-dose ARB with ACE inhibitor (Hawaii) study.

The principal means for reducing proteinuria in patients with chronic kidney disease are strong blockade of the renin-angiotensin system and strict regulation of blood pressure (BP). This study compared the efficacy of the maximum permissible doses of two common angiotensin receptor blockers (ARBs), namely valsartan (maximum dose=160 mg per day) and olmesartan (maximum dose=40 mg per day). We also investigated whether a high-dose ARB or the combination of an angiotensin-converting enzyme inhibitor with a high-dose ARB would be more renal protective. We recruited 87 poorly controlled hypertensive patients. In the first study, 50 patients without proteinuria were switched from valsartan (160 mg per day) to olmesartan (40 mg per day) for 4 months. In the second study, 37 patients with proteinuria were randomized to either switch from valsartan 160 mg per day to 40 mg per day olmesartan (n=19; Olm-G) or addition of 2.5-10 mg per day imidapril (stepped up by 2.5 mg per month) to valsartan at 160 mg per day (n=18; Imi-G). After 4 months, the BP level decreased (first study) from 157/88 mm Hg to 145/82 mm Hg (P<0.001) and (second study) from 149/86 mm Hg to 135/77 mm Hg and 145/82 mm Hg for Olm-G and Imi-G, respectively. Furthermore, in the second study, urinary protein/creatinine excretion was reduced from 2.0±1.8 g g⁻¹ to 0.8±0.8 g g⁻¹ (P=0.0242) in Olm-G and from 1.4±1.3 g g⁻¹ to 0.9±1.0 g g⁻¹ (P=0.0398) in Imi-G. The significance persisted after adjustment for BP or other risk factors. Our results suggested that the maximum dose of olmesartan was more effective than that of valsartan and comparable with the combination of valsartan and imidapril for reducing BP and proteinuria in poorly controlled hypertensive patients.

Loss of ACE2 accelerates time-dependent glomerular and tubulointerstitial damage in streptozotocin-induced diabetic mice.

As angiotensin-converting enzyme-2 (ACE2) was identified as a negative regulator of the renin-angiotensin system, there have been many reports concerning its role in several tissues, including the kidney. However, the role of ACE2 during the development of diabetic nephropathy remains undetermined, as previous reports did not necessarily support a protective role against renal injury. Thus, we performed detailed observations of kidneys in ACE2-knockout (ACE2-KO) mice at early (4 weeks) and advanced (18 weeks) stages of diabetes. ACE2-KO and wild-type C57BL/6 mice were rendered diabetic by intraperitoneal injection of streptozotocin. Diabetic ACE2-KO mice showed earlier onset and more severe progression of albuminuria than those did wild-type mice. The elevation of serum creatinine and urea nitrogen levels at 18 weeks of diabetes was more prominent in ACE2-KO mice. Periodic acid-Schiff-stained cross-section of diabetic ACE2-KO mice showed a more severe time-dependent increase in glomerular/tubulointerstitial damage than did that of wild-type mice, confirmed by the immunostaining of alpha-smooth muscle actin, collagen IV and F4-80 antigen. Glomeruli of diabetic ACE2-KO mice showed earlier and more severe decrease in the expression of nephrin, whose degradation is involved in the onset of albuminuria, and more potent increase of vascular endothelial growth factor expression. In addition, treatment with AT1 receptor blocker olmesartan significantly, but not totally, ameliorated the functional and morphological deterioration of diabetic nephropathy in ACE2-KO mice. These results suggest that ACE2 might continuously protect from both glomerular and tubulointerstitial injury during the development of diabetic nephropathy. The renal-protective effect of ACE2 might involve more than just suppressing angiotensin II-mediated AT1 receptor signaling.

Macrophage inflammatory protein-1beta induced cell adhesion with increased intracellular reactive oxygen species.

UNLABELLED: To investigate the role of macrophage inflammatory protein-1 beta (MIP-1beta) in the development of atherosclerosis, we designed an in vitro study to elucidate the mechanisms of monocyte-endothelium adhesion via intracellular reactive oxygen species (ROS). Angiotensin II (AngII) was used as a positive control. Furthermore, we examined the efficacy of MIP-1beta as a predictor of stroke and cardiovascular events in hypertensive patients. MIP-1beta or AngII stimulation significantly increased ROS production and adhesion of THP-1 cells to inflamed human umbilical vein endothelial cells. Cell adhesion and ROS production were inhibited in stimulated THP-1 cells by: inhibition of ROS signaling with N-acetylcysteine, diphenyleneiodonium, or PEG-Catalase; inhibition of PI3Kgamma with siRNA or LY294002; and by Rac1 siRNA. The MIP-1 beta or AngII stimulation did not increase surface expression of integrins, very late antigen 4 (VLA-4) and lymphocyte function-associated antigen 1 (LFA-1), but cell adhesion was reduced by using an antiVLA-4 or an antiLFA-1 antibody. Moreover, cell adhesion and ROS production stimulated with MIP-1beta or AngII were completely inhibited by fluvastatin. In our clinical study, patients with the highest quartile of MIP-1beta showed a higher risk of stroke and cardiovascular events by a Cox proportional-hazards model. In conclusion, MIP-1beta directly induced cell adhesion to endothelial cells through oxidative stress via PI3k-Rac1 cascades. Serum MIP-1beta level might be a useful predictor for cerebro-cardiovascular events in hypertensive patients. CONDENSED ABSTRACT: We designed an in vitro investigation to examine the role of MIP-1beta on the development of atherosclerosis, including cell adhesion involving CAMs and ROS production, compared with angiotensin II. Furthermore, we investigated the prognostic impact of MIP-1beta on stroke and cardiovascular events in hypertensive patients in a small cohort study.

Comparison of arterial functional evaluations as a predictor of cardiovascular events in hypertensive patients: the Non-Invasive Atherosclerotic Evaluation in Hypertension (NOAH) study.

Increased arterial stiffness and impaired vasodilator response have been associated with cardiovascular events in high-risk patients. However, whether arterial changes predict the occurrence of hypertensive complications is still unclear. Therefore, we designed a hospital-based cohort study to examine the prognostic impact of arterial functional changes on stroke and cardiovascular diseases in hypertensive patients. The study employed 676 patients with essential hypertension. At baseline, we evaluated second-derived photoplethysmography, carotid-femoral pulse wave velocity (PWV), and forearm reactive hyperemia. We classified subjects into quartile groups according to the baseline measurements of these evaluations and assessed the ability of each measure to predict stroke and cardiovascular diseases (CVD). During a mean follow-up period of 57 months, 52 strokes, 40 CVD, and 22 deaths were recorded. Kaplan-Meier analysis revealed that patients in the highest quartile of PWV showed a higher frequency of stroke and CVD (p<0.0001) and total mortality (p=0.0016), and those in the highest quartile of reactive hyperemia showed a lower frequency of stroke and CVD (p=0.0415). A Cox hazard model identified that classification in the highest quartile of PWV (relative risk=2.717) and reactive hyperemia (0.416) were predictive of stroke and CVD after adjustment for other risk factors. In subjects who did not experience stroke or CVD before the study period (n=558), only PWV was related with the occurrence of stroke and CVD based on the Cox hazard model. In conclusion, increased aortic stiffness evaluated by PWV is more prognostic of cardiovascular events in hypertensive patients than several non-invasive atherosclerotic evaluations.

Renal-protective effect of T-and L-type calcium channel blockers in hypertensive patients: an Amlodipine-to-Benidipine Changeover (ABC) study.

Both strict blood pressure control and efferent artery dilatation are critical in reducing proteinuria, which in turn helps to regulate blood pressure. Benidipine, an L- and T-type calcium channel blocker, has the potential for increased effectiveness compared with L-type-dominant calcium channel blockers such as amlodipine. Therefore, we evaluated blood pressure and proteinuria after changeover from amlodipine to benidipine in poorly controlled hypertensive patients. Fifty-eight hypertensive outpatients undergoing amlodipine treatment and unable to achieve optimal blood pressure as determined by Japanese Society of Hypertension Guidelines for the Management of Hypertention (JSH 2004) were changed over to benidipine treatment. We measured blood pressure and pulse rate and assessed urinary protein excretion before and after changeover. Systolic and diastolic blood pressure dropped from 151/90 mmHg to 140/81 mmHg (p<0.0001). Mean blood pressure (p<0.0001) and pulse pressure (p=0.0069) were also reduced, but pulse rate increased from 75 bpm to 78 bpm (p=0.0047). Urinary protein excretion adjusted for urinary creatinine was reduced from 0.35 +/- 0.82 to 0.22 +/- 0.55 g/g creatinine (p=0.0119). The urinary protein reduction was observed only in patients with renin-angiotensin inhibition (p=0.0216). By switching from amlodipine to benidipine treatment, more than 80% of patients reduced their blood pressure, and more than 40% achieved optimal blood pressure. Higher urinary protein excretion (p<0.0001), lower glomerular filtration rate (p=0.0011) and presence of diabetes (p=0.0284) were correlated with reduction of urinary proteins during changeover. Taken together, our results suggest that benidipine may have greater efficacy than amlodipine in reducing blood pressure and proteinuria.

Renin-angiotensin inhibition reverses advanced cardiac remodeling in aging spontaneously hypertensive rats.

BACKGROUND: Many experiments using young hypertensive animal models support the evidence that angiotensin-converting enzyme inhibitor or angiotensin receptor type 1 blocker attenuates the progression of cardiac hypertrophy. However, it is still unclear whether inhibiting the renin-angiotensin system can reverse age-related cardiac hypertrophy. To clarify the role of renin-angiotensin system inhibition in naturally advanced myocardial hypertrophy we treated spontaneously hypertensive, aging rats with an angiotensin-converting enzyme inhibitor or an angiotensin receptor type 1 blocker. METHODS: We used osmotic pumps to deliver the blood-pressure reducers temocaprilat, olmesartan, hydralazine, or saline for 4 weeks. RESULTS: Heart and body weights were significantly reduced in animals treated with temocaprilat or olmesartan compared with animals treated with hydralazine or saline. Histologic myocyte size and cardiac fibrosis were significantly attenuated by temocaprilat or olmesartan. Real-time polymerase chain reaction (PCR) revealed that temocaprilat or olmesartan suppressed expression of cardiac transforming growth factor-beta1 and fibroblast growth factor-2 mRNA, a marker of cardiac fibrosis. Cardiac and systemic oxidative stress assessed by 8-isoprostane levels was significantly reduced in animals treated with temocaprilat or olmesartan compared with hydralazine-treated or saline-treated rats. Renin-angiotensin system inhibition reduced cardiac expression of NAD(P)H oxidative components p22phox, p47phox, and gp91phox. CONCLUSIONS: Renin-angiotensin system inhibition can reverse age-related, advanced cardiac hypertrophy. The mechanism of reversal is partly due to suppression of cardiac oxidative stress.

Renal protective effect in hypertensive patients: the high doses of angiotensin II receptor blocker (HARB) study.

Angiotensin receptor blockers (ARBs) are the recommended first-line antihypertensive treatment for managing chronic kidney disease, and strict blood pressure (BP) regulation is crucial for the reduction of proteinuria. Valsartan and candesartan are commonly used ARBs in Japan, with maximum permissible doses of 160 mg/day and 12 mg/day, respectively. We evaluated BP and proteinuria after changeover from the maximum dose of candesartan to the maximum dose of valsartan, in 55 poorly controlled hypertensive patients undergoing candesartan treatment who were unable to achieve optimal BP according to the Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2004). We measured BP and pulse rate and assessed urinary protein excretion (UPE) before and after changeover. Changeover was associated with decreases in systolic BP and diastolic BP from 158/89 mmHg to 150/86 mmHg (p<0.01). Changeover was also associated with a reduction in UPE adjusted to urinary creatinine from 0.35+/-0.19 g/g creatinine to 0.19+/-0.37 g/g creatinine (p=0.0271) in patients who had high urinary protein levels prior to changeover without significant decreases in BP (p=0.0184). According to multiple regression analysis, higher UPE (p<0.0001) and a lower glomerular filtration rate (GFR) (p=0.0011) prior to changeover were independently correlated with reduction in UPE. Our results suggest that the maximum dose of valsartan is more effective than the maximum dose of candesartan for reducing BP and proteinuria.

Deletion of angiotensin-converting enzyme 2 accelerates pressure overload-induced cardiac dysfunction by increasing local angiotensin II.

Angiotensin-converting enzyme 2 (ACE2) is a carboxypeptidase that cleaves angiotensin II to angiotensin 1-7. Recently, it was reported that mice lacking ACE2 (ACE2(-/y) mice) exhibited reduced cardiac contractility. Because mechanical pressure overload activates the cardiac renin-angiotensin system, we used ACE2(-/y) mice to analyze the role of ACE2 in the response to pressure overload. Twelve-week-old ACE2(-/y) mice and wild-type (WT) mice received transverse aortic constriction (TAC) or sham operation. Sham-operated ACE2(-/y) mice exhibited normal cardiac function and had morphologically normal hearts. In response to TAC, ACE2(-/y) mice developed cardiac hypertrophy and dilatation. Furthermore, their hearts displayed decreased cardiac contractility and increased fetal cardiac gene induction, compared with WT mice. In response to chronic pressure overload, ACE2(-/y) mice developed pulmonary congestion and increased incidence of cardiac death compared with WT mice. On a biochemical level, cardiac angiotensin II concentration and activity of mitogen-activated protein (MAP) kinases were markedly increased in ACE2(-/y) mice in response to TAC. Administration of candesartan, an AT1 subtype angiotensin receptor blocker, attenuated the hypertrophic response and suppressed the activation of MAP kinases in ACE2(-/y) mice. Activation of MAP kinases in response to angiotensin II was greater in cardiomyocytes isolated from ACE2(-/y) mice than in those isolated from WT mice. ACE2 plays an important role in dampening the hypertrophic response to pressure overload mediated by angiotensin II. Disruption of this regulatory function may accelerate cardiac hypertrophy and shorten the transition period from compensated hypertrophy to cardiac failure.

Evaluation of morning blood pressure elevation and autonomic nervous activity in hypertensive patients using wavelet transform of heart rate variability.

To evaluate morning autonomic nervous activity and blood pressure profiles in hypertensive patients by analyzing heart rate variability and ambulatory blood pressure. Data from 82 patients with untreated essential hypertension were analyzed. We evaluated the 24-h profile of blood pressure and that of indices of autonomic nervous activity, i.e., the high frequency component (HF) and low frequency component/HF (LF/HF), which were obtained by wavelet transform of heart rate variability. Patients were classified by dipping status (nondippers, n=28; dippers, n=32; extreme-dippers, n=8; and risers, n=14) and morning blood pressure profile (large, n=9; small, n=60; and inverted, n=13). Nocturnal systolic blood pressure in extreme-dippers was significantly lower than that in the other groups; that in the risers was significantly higher (p<0.05). There were no significant group differences in daytime systolic blood pressure. Daytime and 24-h HF levels were significantly higher in the dipper vs. the riser group (p<0.05). Morning blood pressure elevation negatively correlated to preawake (p<0.01) and nocturnal blood pressure (p<0.05), but not to daytime and post-awake blood pressure. The preawake/postawake ratio of systolic blood pressure positively correlated to that of LF/HF (p<0.01) and negatively correlated to preawake HF levels (p<0.05). Multivariate regression analysis revealed that preawake HF levels (p=0.037) and preawake/postawake ratio of LF/HF (p=0.033) were independently correlated with morning blood pressure elevation ratio. Our results suggest that activation of HF before waking and LF/HF during waking might play an important role in the development of morning blood pressure elevation.

Serum interleukin-15 concentration in patients with essential hypertension.

BACKGROUND: Interleukin (IL)-15 is one of the cytokines produced by neutrophils and monocytes/macrophages, and its expression is found immunohistochemically in inflammatory cells adjacent to vulnerable atherosclerotic plaques. However, the influence of systemic IL-15 on cardiovascular disease is still unclear. Therefore, we designed clinical investigations to clarify the relationship between cardiovascular complications and serum IL-15 levels. METHODS AND RESULTS: Three hundred ninety-nine patients with essential hypertension were analyzed. We divided the study subjects into the following three groups according to the modified World Health Organization-International Society of Hypertension classification of 1999: patients with no organ damage (n = 213), patients with mild organ damage (n = 128), and patients with severe organ damage (n = 58). We measured serum IL-15, highly sensitive C reactive protein, IL-6, soluble intercellular adhesion molecule, and soluble vascular cell adhesion molecule levels. Serum IL-15 concentration in patients with severe organ damage was significantly higher than that in those with no organ damage (P < .01) and those with mild organ damage (P < .01). Serum IL-15 concentration in patients with coronary artery disease or peripheral artery disease was significantly higher than that in those without coronary artery disease or peripheral artery disease. Moreover, serum IL-15 concentration in patients with lacunar infarction was significantly higher than that in those without lacunar infarction (P < .005). By multiple linear logistic regression analysis, serum IL-15 concentration was independently correlated with cardiovascular disease. CONCLUSIONS: These data suggest that a systemic inflammatory response involving IL-15 might be involved in the occurrence of cardiovascular disease in patients with essential hypertension.