Pathogenesis and clinical physiology of hypertension

Liensinine improves AngII-induced vascular remodeling via MAPK/TGF-β1/Smad2/3 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Liensinine(Lien, C37H42N2O6) is an alkaloid compound from plumula nelumbinis that demonstrates an antihypertensive effect. The protective effects of Lien on target organs during hypertension are still unclear.

AIM OF THE STUDY

This study aimed to understand the mechanism of Lien during the treatment of hypertension, with emphasis on vascular protection.

MATERIALS AND METHODS

Lien was extracted and isolated from plumula nelumbinis for further study. In vivo model of Ang II-induced hypertension, non-invasive sphygmomanometer was used to detect the blood pressure in and out of the context of Lien intervention. Ultrasound was used to detect the abdominal aorta pulse wave and media thickness of hypertensive mice, and RNA sequencing was used to detect the differential genes and pathways of blood vessels. The intersection of Lien and MAPK protein molecules was detected by molecular interconnecting technique. The pathological conditions of abdominal aorta vessels of mice were observed by HE staining. The expression of PCNA, α-SMA, Collagen Type Ⅰ and Collagen Type Ⅲ proteins were detected by IHC. The collagen expression in the abdominal aorta was detected by Sirius red staining. The MAPK/TGF-β1/Smad2/3 signaling and the protein expression of PCNA and α-SMA was detected by Western blot. In vitro, MAPK/TGF-β1/Smad2/3 signaling and the protein expression of PCNA and α-SMA were detected by Western blot, and the expression of α-SMA was detected by immunofluorescence; ELISA was used to detect the effect of ERK/MAPK inhibitor PD98059 on Ang Ⅱ-induced TGF-β1secrete; and the detection TGF-β1and α-SMA protein expression by Western blot; Western blot was used to detect the effect of ERK/MAPK stimulant12-O-tetradecanoyl phorbol-13-acetate (TPA) on the protein expression of TGF-β1 and α-SMA.

RESULTS

Lien displayed an antihypertensive effect on Ang Ⅱ-induced hypertension, reducing the pulse wave conduction velocity of the abdominal aorta and the thickness of the abdominal aorta vessel wall, ultimately improving the pathological state of blood vessels. RNA sequencing further indicated that the differential pathways expressed in the abdominal aorta of hypertensive mice were enriched in proliferation-related markers compared with the Control group. The profile of differentially expressed pathways was ultimately reversed by Lien. Particularly, MAPK protein demonstrated good binding with the Lien molecule. In vivo, Lien inhibited Ang Ⅱ-induced abdominal aorta wall thickening, reduced collagen deposition in the ventral aortic vessel, and prevented the occurrence of vascular remodeling by inhibiting MAPK/TGF-β1/Smad2/3 signaling activation. In addition, Lien inhibited the activation of Ang II-induced MAPK and TGF-β1/Smad2/3 signaling, attenuating the expression of PCNA and inhibiting the reduction of α-SMA, collectively playing a role in the inhibition of Ang Ⅱ-induced hypertensive vascular remodeling. PD98059 alone could inhibit Ang Ⅱ-induced elevation of TGF-β1 and the decrease of α-SMA expression. Further, PD98059 combined with Lien had no discrepancy with the inhibitors alone. Simultaneously TPA alone could significantly increase the expression of TGF-β1 and decrease the expression of α-SMA. Further, Lien could inhibit the effect of TPA.

CONCLUSION

This study helped clarify the protective mechanism of Lien during hypertension, elucidating its role as an inhibitor of vascular remodeling and providing an experimental basis for the research and development of novel antihypertensive therapies.

Evaluation of Blood Pressure Status and Mortality in Turkey: Findings from Chronic Diseases and Risk Factors Cohort Study

Background and objectives: An important Non-Communicable Disease risk factor, hypertension (HT), is highly prevalent and controlled HT rates are not sufficient which increases the risk of developing premature deaths. The purpose of the study is to evaluate differences in all-cause and cardiovascular-related mortality according to HT status by using national data from Chronic Diseases and Risk Factors Survey in Turkey (2011-2017). Materials and Methods: Cox regression models were used to estimate hazard ratios (HR) for predicting the all-cause and cardiovascular system-related mortalities. Median follow-up period was 6.2 years. Results: Among individuals with HT, 41.8% was untreated, 30.1% received treatment and had controlled blood pressure, and 28.1% were under treatment but had uncontrolled BP levels. The hazard for mortality among treated & uncontrolled hypertensive participants was significantly higher for all-cause (HR = 1.32, 95% CI = 1.06-1.65), cardiovascular (HR = 2.11, 95% CI = 1.46-3.06), heart disease (HR = 2.24, 95% CI = 1.46-3.43), and Coronary Heart Disease mortality (HR = 2.66, 95% CI = 1.56-4.53) compared to normotensive participants. Conclusions: Individuals with HT who were treated but do not have controlled blood pressure in Turkey had a significantly increased risk of Cardiovascular Disease and all-cause mortality. Along with studies investigating the causes of uncontrolled blood pressure despite initiation of treatment, support should be provided to patients in cases of non-adherence to antihypertensive medication or life change recommendations.

[¿Cómo tratar la hipertensión arterial sistémica? Estrategias de tratamiento actuales]

Hypertension is a disease that affects almost half of the population. Its complex pathophysiology, mainly affecting the renal, hormonal, cardiovascular and neurological systems, has allowed us to have different pharmacological strategies to treat each of these systems and thus regulate blood pressure. The American Heart Association in 2017, the European Society of Cardiology in 2018, and the American Society of Hypertension in 2020 published their recommendations for the diagnosis, monitoring and treatment of arterial hypertension. The definition of normal blood pressure or hypertension varies according to each guideline. Recommendations on lifestyle and pharmacological therapy are very similar in the guidelines. They recommend blockers of the renin-angiotensin system, calcium antagonists and thiazides, and only in selected cases the use of mineralocorticoid receptor antagonist or beta-blockers.

Low serum corin levels predict end-organ damage in patients with hypertensive crisis

OBJECTIVE

The study aimed to investigate the predictive power of serum corin levels for distinguishing between hypertensive urgency (HU) and hypertensive emergency (HE) in patients with hypertensive crisis (HC) admitted to the emergency department.

METHODS

A total of 120 consecutive consenting adult patients diagnosed with HC and 55 age- and sex-matched healthy controls were enrolled. Blood pressure measurements [(systolic, diastolic, and mean arterial pressure (MAP)] and the evidence of end-organ damage at the first admission were recorded. Patients with HC were classified as patients with HE or HU according to the presence or absence of acute end-organ damage. Serum corin levels were compared between the 2 groups.

RESULTS

The mean serum corin level was significantly lower in the HC group than in the control group; it was also lower in the HE group than in the HU group (p<0.001 for all). In the HE group, clinical features associated with end-organ damage included ST-elevation myocardial infarction (n=28, 46.7%), hemorrhagic stroke (n=11, 18.3%), ischemic stroke (n=11, 18.3%), and non-ST-elevation myocardial infarction (n=10, 16.7%). The receiving operator characteristic (ROC) analysis identified a serum corin cutoff value of 45 pg/mL for distinguishing patients with HE from patients with HU with 98.3% sensitivity and 95% specificity.

CONCLUSION

Our findings suggest that serum corin levels play an important role in regulating blood pressure and are involved in the pathogenesis of HC. Low serum corin levels may predict end-organ damage and serve as a guide for diagnostic decision making in patients with HC.

The effect of family history of hypertension and polymorphism of the ACE gene (rs1799752) on cardiac autonomic modulation in adolescents

This study aims to analyze the behaviour of cardiac autonomic modulation in adolescents with a family history of hypertension along with polymorphism of the ACE gene (rs1799752). The study involved 141 adolescents, with a mean age of 14.89, divided into the following six groups: offspring of normotensive parents (ONP): DD, DI and II; and offspring of hypertensive parents (OHP): DD, DI and II. Blood pressure, body composition, family history of hypertension, sleep disorder, and sexual maturation were assessed for the groups' characterization. Afterwards, an electrocardiogram was performed, and oral mucosal cells were collected to analyze heart rate variability and genotypic research of angiotensin-converting enzyme. The main finding of this study was the decrease of vagal action in group OHP (genotype DD) relative to group ONP (genotype II): LF (%), 54.25 ± 3.14 vs 39.33 ± 3.80; HF (%), 45.74 ± 3.14 vs 60.66 ± 3.80; LF/HF, 1.48 ± 0.23 vs 0.68 ± 0.19. The results also showed changes in the variable diastolic blood pressure (DBP) in OHP (genotype DI) to ONP (genotype II) groups: 72.99 ± 2.33 vs 63.27 ± 1.72; and OHP (genotype DI) to ONP (genotype DD) groups. Adolescents with genotype DD and a family history of arterial hypertension present chances in cardiac autonomic modulation, the cardiac parasympathetic modulation is lower in these adolescents in comparison to participants of ONP + II group.

Sex modification of the association of the radial augmentation index and incident hypertension in a Chinese community-based population

BACKGROUND

Arterial stiffness, as assessed by aortic ultrasound and pulse wave velocity, is associated with incident hypertension. However, there is still no consensus on whether the augmentation index (AI) affects new onset of hypertension. This study investigated the relationship of radial AI (rAI) and incident hypertension in a Chinese community-based population without hypertension at baseline.

METHOD

A total of 1,615 Chinese non-hypertensive participants from an atherosclerosis cohort in Beijing, China were included in our analysis. Baseline rAI normalized to heart rate of 75 beats/min (rAIp75) was obtained using HEM-9000AI. New-onset hypertension was defined as blood pressure ≥ 140/90 mmHg or self-reported hypertension or taking anti-hypertensive medications at the follow up survey. Multivariate regression models were used to evaluate the impact of rAIp75 on the risk of new-onset hypertension.

RESULTS

After a mean 2.35-year follow-up, 213 (13.19%) participants developed incident hypertension. No significant relation between rAIp75 and incident hypertension was observed in the whole population after adjustment for possible confounders (adjusted odds ratio (OR) and 95% confidence interval (CI): 1.09 [0.95-1.27];P = 0.2260). However, rAIp75 was significantly associated with incident hypertension in women, but not in men (adjusted OR and 95% CI: 1.29 [1.06-1.56],P = 0.0113 for women; 0.91 [0.72-1.15],P = 0.4244 for men; P for interaction = 0.0133).

CONCLUSIONS

Sex modified the effect of the rAI on incident hypertension in a Chinese, community-based, non-hypertensive population. Screening of the rAI could be considered in women with a high risk of hypertension for the purpose of primary intervention.

Association of single nucleotide polymorphisms of MTHFR, TCN2, RNF213 with susceptibility to hypertension and blood pressure

Methylenetetrahydrofolate reductase gene (MTHFR), transcobalaminII (TCN2) and ring finger protein 213 (RNF213) are related to homocysteine (Hcy) level and are of great significance for hypertension. We aimed to evaluate the associations of MTHFR (rs1801133, rs1801131, rs9651118), TCN2 (rs117353193) and RNF213 (rs9916351) with hypertension and blood pressure (BP). A total of 953 patients with hypertension and 1103 controls were enrolled. Genotyping was performed by Taqman. Logistic regression analysis indicated that A allele of TCN2 rs117353193 under the dominant model had a significantly protective effect (P=0.045) after adjustment, which showed that AA+GA genotype has a lower risk than GG. Additionally, the average diastolic BP (DBP) (P=0.044) and mean arterial pressure (MAP) (P=0.035) levels were significantly different between genotypes of RNF213 rs9916351. Further pairwise comparison showed that the average systolic BP (SBP) level of the TT genotype carriers were significantly higher than in CC (P=0.024), and the average DBP and MAP levels of the TT genotype carriers were higher than in CT (P=0.044, P=0.012, respectively) and CC (P=0.048, P=0.010, respectively). In the recessive model, the average SBP (P=0.043), DBP (P=0.018) and MAP (P=0.017) levels with the TT genotype carriers were significantly higher than in CT+CC. Multiple linear regression analysis suggested that RNF213 rs9916351 in the recessive model had significant effects on SBP (P=0.025), DBP (P=0.017) and MAP (P=0.010) as a risk factor. However, no associations were observed between MTHFR and hypertension. TCN2 rs117353193 might serve as a protective factor in hypertension, and RNF213 rs9916351 might be a risk factor that is linked to increase BP level in Northeast Chinese population.

A comprehensive evaluation of association between homocysteine levels and single nucleotide polymorphisms with hypertension risk: A protocol of systematic review and network meta-analysis

BACKGROUND

According to the relevant reports that single nucleotide polymorphisms (SNPs) may contribute to change of homocysteine (HCY) levels and increase the risk of hypertension (HTN). During the inconsistent results, this meta-analysis purpose is systematically review and synthesized relevant data on HCY levels and SNPs in HTN.

METHODS

The systematic search database, from the following database to find out the association studies of SNPs and HTN publications up until March 2020 from the databases of PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), the Chinese Science and Technology Periodical Database (VIP) and Wan fang databases, and Chinese Biomedical Literature Database (CBM). Network meta-analysis and Thakkinstian's algorithm were used to select the most appropriate genetic model, along with false positive report probability (FPRP) for noteworthy associations. All statistical analyses were calculated with STATA software (version 14.0; StataCorp, College Station, TX).

RESULTS

This meta-analysis will provide high-quality evidence to the effects of SNP on HTN and levels of HCY, and find between SNPs and HTN susceptibility on in all the genetic models, and choose the best one.

CONCLUSIONS

This meta-analysis will research which SNP is the most correlated with HTN risk.

REGISTRATION

INPLASY202050002.

Effects of Olive Oil on Blood Pressure: Epidemiological, Clinical, and Mechanistic Evidence

The increasing access to antihypertensive medications has improved longevity and quality of life in hypertensive patients. Nevertheless, hypertension still remains a major risk factor for stroke and myocardial infarction, suggesting the need to implement management of pre- and hypertensive patients. In addition to antihypertensive medications, lifestyle changes, including healthier dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to favorably affect blood pressure and are now recommended as integrative tools in hypertension management. An analysis of the effects of nutritional components of the Mediterranean diet(s) on blood pressure has therefore become mandatory. After a literature review of the impact of Mediterranean diet(s) on cardiovascular risk factors, we here analyze the effects of olive oil and its major components on blood pressure in healthy and cardiovascular disease individuals and examine underlying mechanisms of action. Both experimental and human studies agree in showing anti-hypertensive effects of olive oil. We conclude that due to its high oleic acid and antioxidant polyphenol content, the consumption of olive oil may be advised as the optimal fat choice in the management protocols for hypertension in both healthy and cardiovascular disease patients.

Evaluation of pharmacokinetics and safety with bioequivalence of Amlodipine in healthy Chinese volunteers: Bioequivalence Study Findings

Background and Objective

Amlodipine, a main series of L‐type calcium channel blockers (CCBs), exerts potent antihypertensive effects. The aim of this trial was to explore the pharmacokinetics (PK) and safety with bioequivalence of orally administered Amlodipine provided by two sponsors in healthy volunteers (HVs).

Methods

Two separate randomized, open‐label, single‐dose, crossover‐design studies were conducted: a fasting study (n = 24) and a fed study (n = 24). In each study, HVs were randomized to Fangming Pharmaceutical Group (Test, T) followed by NORVASC^® (Reference, R), or vice versa. Each study subject received a 5‐mg Amlodipine tablet with a 15‐day washout. The plasma concentrations of Amlodipine were measured using a LC‐MS/MS method, and PK parameters were determined by noncompartmental model.

Results

Forty‐eight healthy volunteers were enrolled. And overall demographics were as follows: the fasting study: female (n = 16/24), age (18‐54 years), weight (47‐76 kg), and BMI (19.5‐26.0). The fed study: female (n = 16/24), age (20‐49 years), weight (45.5‐69 kg), and BMI (19.1‐25.0). All PK endpoints met the pre‐specific criteria for PK equivalence. In fasting subjects, the maximum plasma concentration (C_max) was 3.881 ± 0.982 ng/mL at 6 hours (median) of sponsor T, and 4.042 ± 1.147 ng/mL at 6 hours (median) of sponsor R. In fed subjects, C_max was 3.312 ± 0.789 ng/mL at 6 hours (median) of sponsor T, and 3.392 ± 0.902 ng/mL at 5 hours (median) of sponsor R. Both fasting and fed studies achieved a plausible bioequivalence.

Conclusions

Amlodipine is well tolerated and have a favorable safety profile. The observed adverse events were mild (the severity was assessed according to the Common Terminology Criteria for Adverse Events [version CTCAE4.03]) and all of them were recovered without severe sequences. And the bioequivalence is achieved under fasting and fed conditions, supporting the demonstration of biosimilarity.

Oxidative stress and vascular stiffness in hypertension: A renewed interest for antioxidant therapies?

Since the first successful launch of the Veterans Administration(VA) cooperative studies in the late 1960s, the increasing access to blood pressure lowering medications has significantly contributed to improving longevity and quality of life in hypertensive patients. Since then, insights into the pathogenesis of hypertension have shown a mechanistic role for reactive oxygen species (ROS) in all phases of disease progression, suggesting the potential utility of antioxidant therapies to counteract symptoms and, at the same time, treat a fundamental mechanism of the disease. Despite these progresses, hypertension still remains the main contributor to the global incidence of cardiovascular disease and the leading cause of morbidity and mortality worldwide. We here briefly review and update the role of ROS and ROS-dependent metalloproteinase activation in the maladaptive remodeling of the vascular wall in hypertension. Such understanding should provide new Potential sites of action for antioxidant therapies as an integrated therapeutic approach to hypertension and its consequences.

Pediatric Hypertension: Diagnosis, Evaluation, and Treatment

The etiology of hypertension in children and adolescents is varied; however, the prevalence of pediatric primary hypertension is increasing. Early identification and appropriate management of hypertension in children and adolescents is important to prevent the development of hypertensive end organ disease. The 2017 American Academy of Pediatrics Clinical Practice Guidelines for the Screening and Management of High Blood Pressure in Children and Adolescents provide a comprehensive reference for evaluation and management of hypertension in this age group and should be used when assessing patients with elevated blood pressure and hypertension.

Inhibition of angiotensin II receptor I prevents inflammation and bone loss in periodontitis

BACKGROUND

Periodontal disease is characterized by alveolar bone destruction and degenerative lesions of the periodontal ligament (PDL); it is initiated by bacterial infection of the oral cavity, but the clinical effects are secondary to an aberrant host immune response. Primary hypertension (PH), which causes significant morbidity and mortality worldwide, has also been shown to be an inflammatory disease characterized by aberrant immune cell infiltration and activation. Clinical retrospective studies have shown a link between PH and periodontitis with PH exacerbating periodontitis and vice versa, but the pathophysiologic mechanisms responsible for this remain unknown.

METHODS

In this study, we investigate the underlying mechanisms behind PH exacerbation of periodontitis by using a bacteria-induced periodontitis model in normotensive and hypertensive (Nos3^-/- ) mice treated with or without an Angiotensin II (Ang II) specific receptor 1 (AT1) antagonist, losartan. The histologic analyses including immunohistochemistry, immunofluorescence were carried out. The qRT-PCR and ELISAs were applied for the target gene and protein detection.

RESULTS

We find that PH worsens bone resorption and PDL destruction in periodontitis and that treatment with losartan, rescues this. We also show that PH increases dendritic cell (DC) and osteoclast (OC) infiltration in periodontitis, which is also dependent on Ang II. Finally, we show that PH augments the pro-inflammatory state in periodontitis infiltrating DCs in an Ang II-dependent manner and use in vitro studies to show that Ang II directly augments DC Toll-like receptor 4 (TLR4) signaling.

CONCLUSION

Our studies show a central role for Ang II as a pro-inflammatory Toll-like receptor mediator in the pathogenesis of PH-exacerbated periodontitis, indicating that Ang II may be a reasonable target in patients with PH and periodontitis comorbidity.

Effects of chronic exposure to 12‰ saltwater on the endocrine physiology of juvenile American alligator (Alligator mississippiensis)

American alligator (Alligator mississippiensis) habitats are prone to saltwater intrusion following major storms, hurricanes or droughts. Anthropogenic impacts affecting hydrology of freshwater systems may exacerbate saltwater intrusion into freshwater habitats. The endocrine system of alligators is susceptible to changes in the environment but it is currently not known how the crocodilian physiological system responds to environmental stressors such as salinity. Juvenile alligators were exposed to 12‰ saltwater for 5 weeks to determine the effects of chronic exposure to saline environments. Following 5 weeks, plasma levels of hormones [e.g. progesterone, testosterone, estradiol, corticosterone, aldosterone (ALDO), angiotensin II (ANG II)] were quantified using liquid chromatography and tandem mass spectrometry. Compared with freshwater-kept subjects, saltwater-exposed alligators had significantly elevated plasma levels of corticosterone, 11-deoxycortisol, 17α-hydroxyprogesterone, testosterone, 17β-estradiol, estrone and estriol whereas pregnenolone and ANG II were significantly depressed and ALDO levels were unchanged (slightly depressed). On the one hand, saltwater exposure did not affect gene expression of renal mineralocorticoid and glucorticoid and angiotensin type 1 (AT-1) receptors or morphology of lingual glands. On the other hand, saltwater exposure significantly reduced plasma glucose concentrations whereas parameters diagnostic of perturbed liver function (aspartate aminotransferase and alanine aminotransferase) and kidney function (creatinine and creatine kinase) were significantly elevated. Except for plasma potassium levels (K⁺), plasma ions Na⁺ and Cl^- were significantly elevated in saltwater alligators. Overall, this study demonstrated significant endocrine and physiological effects in juvenile alligators chronically exposed to a saline environment. Results provide novel insights into the effects of a natural environmental stressor (salinity) on the renin-angiotensin-aldosterone system and steroidogenesis of alligators.

Utilizing proteomics to understand and define hypertension: where are we and where do we go?

INTRODUCTION

Hypertension is a complex and multifactorial cardiovascular disorder. With different mechanisms contributing to a different extent to an individual's blood pressure, the discovery of novel pathogenetic principles of hypertension is challenging. However, there is an urgent and unmet clinical need to improve prevention, detection, and therapy of hypertension in order to reduce the global burden associated with hypertension-related cardiovascular diseases. Areas covered: Proteomic techniques have been applied in reductionist experimental models including angiotensin II infusion models in rodents and the spontaneously hypertensive rat in order to unravel mechanisms involved in blood pressure control and end organ damage. In humans proteomic studies mainly focus on prediction and detection of organ damage, particularly of heart failure and renal disease. While there are only few proteomic studies specifically addressing human primary hypertension, there are more data available in hypertensive disorders in pregnancy, such as preeclampsia. We will review these studies and discuss implications of proteomics on precision medicine approaches. Expert commentary: Despite the potential of proteomic studies in hypertension there has been moderate progress in this area of research. Standardized large-scale studies are required in order to make best use of the potential that proteomics offers in hypertension and other cardiovascular diseases.

Phthalate exposure as a risk factor for hypertension

Phthalates are ubiquitous in environment. Hypertension is a major risk factor for cardiovascular diseases. Phthalate exposure is associated with hypertension in multiple studies. This review aims to summarize the scientific literature on associations between phthalate exposure and hypertension and discuss the mechanisms in the relationship. We identified and reviewed original articles published to March 2018, using PubMed and Web of Science to search the terms "phthalate(s)," "phthalic acid," "blood pressure," "high blood pressure," "hypertension," "prehypertension," and "cardiovascular disease." Findings were summarized based on the relevance to the themes, including presentation of main phthalates and their major metabolites as well as associations of phthalate exposure with blood pressure in epidemiological and experimental studies. We identified ten population-based investigations and five toxicological experiments. Epidemiological data underscored a possible correlation between phthalate exposure and hypertension in adults, whereas individual study in children stands on the opposite. Experimental studies mainly targeted the increasing effect of phthalates on blood pressure. This review suggested some underlying mechanisms of phthalate-associated hypertension. Considering the current evidence, phthalate might be risk factors of hypertension. However, the effect of phthalate exposure in early life on blood pressure in later life or adulthood is still unclear. Well-designed longitudinal and molecular mechanism studies are indispensable.

Blood pressure control and its determinants among diabetes mellitus co-morbid hypertensive patients at Jimma University medical center, South West Ethiopia

BACKGROUND

Hypertension is the major contributor to cardiovascular diseases related morbidity and mortality. Blood pressure is not well controlled in the majority of patients with both diabetes and hypertension. The main objective of this study was to assess blood pressure control and its determinants among diabetes mellitus co- morbid hypertensive ambulatory patients.

METHODS

Hospital based cross sectional study was conducted among diabetes mellitus co-morbid hypertensive ambulatory adult patients based on the inclusion criteria. Patient specific data was collected using structured data collection tool. Data was analyzed using statistical software package, SPSS version 20.0. To identify the independent predictors of blood pressure control, multiple stepwise backward logistic regression analysis was done. Statistical significance was considered at p-value <0.05. Patient's written informed consent was obtained after explaining the purpose of the study. Patients were informed about confidentiality of the information obtained.

RESULTS

From a total of 131 study participants 51.14% were males with the mean (SD) age of the 50.69 ± 13.71. The mean duration of time since the diagnosis of hypertension was 7.44 ± 5.11 years. The mean (SD) SBP was 149.79 ± 16.32 mmHg, while the mean (SD) DBP was 89.77 ± 9.34 mmHg. More than one fourth (25.20%) of study participants had a controlled SBP, while about 27.48% had a controlled DBP. The overall control of BP was achieved in about 57 (43.51%) of the study participants. Older age (≥50 years) (AOR = 2.06; 95% CI: 2.65-7.79; P = 0.002), female gender (AOR = 1.42; 95% CI: 1.19-2.14; P = 0.042), duration of hypertension (AOR = 2.88, 95% CI: 1.27, 8.31, P = 0.02), non-adherence (AOR 2.05; 95% CI: 2.61-9.33; P = 0.01) and uncontrolled blood sugar(AOR = 1.65; 95% CI: 2.14-3.32; P = 0.04) are independent predictors for uncontrolled blood pressure.

CONCLUSIONS

Blood pressure control to target goal was suboptimal in the study area. Diabetic patients who were older, female, live longer duration with hypertension, non-adherent to their medications and poor glycemic control were more likely to have uncontrolled BP. Therefore, more effort should be dedicated to control the blood pressure in diabetics.

Renin-angiotensin system gene polymorphisms and high blood pressure in Lithuanian children and adolescents

Background

Epidemiological studies have demonstrated the influence of environmental factors on HBP in the population of Lithuanian children, although the role of genetic factors in hypertension has not yet been studied. The aim of this study was to assess the distribution of AGTR1, AGT, and ACE genotypes in the Lithuanian child population and to determine whether these genotypes have an impact on HBP in childhood.

Methods

This cross-sectional study enrolled 709 participants aged 12–15 years. The subjects were genotyped for AGT (M235 T, rs699), AGTR1 (A1166C, rs5186), and ACE (rs4340) gene polymorphisms using real-time and conventional polymerase chain reactions. Blood pressure and anthropometric parameters were measured.

Results

The prevalence of HBP was 38.6% and was more frequently detected in boys than in girls (47.9% vs. 29.5%; p < 0.001). No significant differences in the frequencies of the AGT or AGTR1 genotypes or alleles between boys and girls were observed, except for ACE genotypes. The mean SBP value was higher in HBP subjects with ACE ID genotype compared to those with ACE II homozygotes (p = 0.04). No significant differences in BP between different AGT and AGTR1 genotype groups were found. Boys who carried the ACE ID + DD genotypes had higher odds of having HBP than carriers of the ACE II genotype did (controlling for the body mass index (BMI): OR_MH = 1.83; 95% CI, 1.11–3.02, p = 0.024; and controlling for waist circumference (WC): OR_MH = 1.76; 95% CI, 1.07–2.92, p = 0.035). These associations were not significant among girls. The same trend was observed in the multivariate analysis – after adjustment for BMI and WC, only boys with ACE ID genotype and ACE ID + DD genotypes had statistically significantly increased odds of HBP (aOR = 2.05; 95% CI, 1.19–3.53 (p = 0.01) and aOR = 1.82; 95% CI, 1.09–3.04 (p = 0.022), respectively).

Conclusions

The evaluated polymorphisms of the AGT and AGTR1 genes did not contribute to the presence of HBP in the present study and may be seen as predisposing factors, while ACE ID genotypes were associated with significantly increased odds for the development of HBP in the Lithuanian child and adolescent population - especially in boys.

YKL-40 is a novel biomarker for predicting hypertension incidence among prehypertensive subjects: A population-based nested case-control study in China

BACKGROUND AND AIMS

The previous study suggested that Human cartilage glycoprotein-39 (YKL-40) was positively associated with hypertension incidence in certain high-risk groups of hypertension. We aimed to investigate that whether YKL-40 is an effective biomarker for predicting hypertension incidence among prehypertensive subjects.

METHODS

In a 1:1 matched case-control study of 700 pairs with available YKL-40 levels nested in a prospective cohort of initially healthy Chinese subjects, 294 pairs additionally have matched baseline BP status (prehypertensive or normotensive). Multivariable conditional logistic regression analyses were used to calculate the odds ratios (95% confidential intervals) of hypertension associated with higher levels of YKL-40 in both prehypertensive and normotensive subgroups, respectively.

RESULTS

In the prehypertensive subgroup, the subjects in the highest quartile of plasma YKL-40 levels had a significantly higher risk of hypertension incidence, compared with those in the lowest quartile. The odds ratio (95% confidential intervals) is 2.01 (1.05-3.85). A positive association between YKL-40 levels and hypertension incidence was found (P for trend<0.05). However, this significant association was not observed in the normotensive subgroup.

CONCLUSIONS

Higher YKL-40 levels at baseline were positively associated with hypertension incidence among prehypertensive subjects. YKL-40 may represent a novel biomarker for predicting hypertension risk in prehypertension population.

The Antihypertensive Efficacy of the Triple Fixed Combination of Perindopril, Indapamide, and Amlodipine: The Results of the PETRA Study

INTRODUCTION

The etiology of essential hypertension is multifactorial. Therefore, treatment with combinations of antihypertensive agents acting on multiple targets is necessary for successful therapy in the majority of patients. According to the experience and clinical data accumulated so far, combination therapy with three agents from different pharmacological classes is required in approx. 30% of patients in order to achieve long-term blood pressure control. The primary objective of the PETRA study was to evaluate the efficacy of blood pressure (BP) control with once daily administration of the different dosage strengths of the once-daily, triple fixed combination of perindopril, indapamide, and amlodipine. The evaluation was based on office BP readings and ambulatory blood pressure monitoring (ABPM) data gathered in routine clinical practice.

METHODS

Data from 11,209 hypertensive patients (the proportion of female subjects was 47.6%) were processed and interpreted in a 3-month-long prospective, observational, non-interventional, open-label study conducted in 997 centers in Hungary.

RESULTS

Mean baseline office BP was 156.58 ± 16.10/91.56 ± 9.33 mmHg (mean ± SD), whereas the mean duration of hypertension was 9.48 ± 7.19 years. Mean office BP decreased by 24.81 ± 15.47/11.41 ± 9.90 mmHg after switching to the triple fixed combination of perindopril, indapamide, and amlodipine (p < 0.0001). At the final visit 45.1% of patients took the 5/1.25/5 mg, 33.5% of them 10/2.5/5 mg, and 21.4% of them 10/2.5/10 mg strength of the perindopril/indapamide/amlodipine triple fixed combination. The 24-h blood pressure was obtained in 76 subjects. The mean 24-h BP decreased from 155.51 ± 17.43/85.28 ± 11.48 to 134.63 ± 12.51/77.83 ± 8.99 mmHg (p < 0.0001). Statistically significant (p < 0.0001) and clinically relevant improvement of a number of metabolic parameters-including total cholesterol (-8.6%), LDL-cholesterol (-11.4%), triglyceride (-12.1%), and fasting blood glucose (-6.6%) levels-was observed over the 3-month study period.

CONCLUSIONS

During the 3 months of the PETRA study, the outstanding 24-h antihypertensive efficacy of the triple fixed combination of perindopril, indapamide, and amlodipine was confirmed both by office BP readings and by ABPM recordings. This combination may offer a new therapeutic option for hypertensive patients who have failed to achieve the desired BP target on their previous dual combination therapy.

FUNDING

EGIS Pharmaceuticals PLC.

Astaxanthin in cardiovascular health and disease: mechanisms of action, therapeutic merits, and knowledge gaps

Cardiovascular disease is the main contributor to morbidity and mortality worldwide.

The effect of resveratrol on hypertension: A clinical trial

The aim of this clinical trial was to investigate the effects of Evelor, a micronized formulation of resveratrol (RESV; 3,5,4'-trihydroxy-trans-stilbene), in patients with primary hypertension. RESV is a stilbenoid and phytoalexin produced by several plants in response to injury or attack by pathogens, such as bacteria and fungi. Patients included in the clinical trial were split into the following two groups, based on the severity of their disease: Group A (n=46), stage I hypertension [systolic blood pressure (SBP), 140-159 mmHg; diastolic blood pressure (DBP), 90-99 mmHg] and Group B (n=51), stage II hypertension (SBP, 160-179 mmHg; DBP, 100-109 mmHg). Each group was divided into two subgroups: A1 and B1, patients treated with standard antihypertensive therapy (A1, 10 mg Dapril; B1, 20 mg Dapril), and A2 and B2, patients treated with antihypertensive therapy (Dapril) plus Evelor. The present study aimed to determine the effects of Evelor, in addition to the standard hypertension treatment, and its effect on the hepatic enzymes serum glutamate-pyruvate transaminase (SGPT) and gamma-glutamyl transferase (gamma-GT). Following the trial, which lasted two years (October 2010 to October 2012), the mean blood pressure of both groups lay within the normal range, indicating that blood pressure was efficiently controlled. The results of the present study demonstrate that the addition of RESV to standard antihypertensive therapy is sufficient to reduce blood pressure to normal levels, without the need for additional antihypertensive drugs. In addition, statistical analysis of the results identified a significant reduction in plasma concentration levels of SGPT (P<0.001) and gamma-GT (P<0.001) with the addition of RESV, indicating that RESV prevents liver damage.

YKL-40 Level and Hypertension Incidence: A Population-Based Nested Case-Control Study in China

Background

Human cartilage glycoprotein‐39 (YKL‐40) has been suggested to be a new marker of inflammation, atherosclerosis, and endothelial dysfunction. However, whether a higher level of YKL‐40 is an independent risk factor for hypertension incidence is still unknown.

Methods and Results

In a nested case‐control study within a prospective cohort of 12 423 initially healthy Chinese adults, we measured baseline plasma concentrations of YKL‐40 among 700 new‐onset hypertension cases and 700 age‐ and sex‐matched controls. Multiple conditional logistic regression analyses were used to calculate the odds ratios (95% CIs) of hypertension associated with higher levels of YKL‐40 both in the total population and in the age‐ (>55 and ≤55 years) and sex‐matched subgroups. Among the total population, YKL‐40 levels were not associated with hypertension risk. In the subgroup older than 55 years, odds ratios (95% CIs) of hypertension for those in the two higher tertiles of YKL‐40 were 1.23 (0.77–1.97) and 1.59 (0.99–2.55) (P for linear trend=0.05). In the male subgroup, odds ratios (95% CIs) of hypertension for those in the two higher tertiles of YKL‐40 were 1.55 (0.88–2.72) and 2.09 (1.14–3.82) (P for linear trend=0.02). An interaction effect was observed between YKL‐40 and sex (P for interaction <0.01) but not between YKL‐40 and age (P for interaction=0.21). High YKL‐40 level significantly increased hypertension risk in men but decreased hypertension risk with a trend although not significant in women.

Conclusions

This study suggests that YKL‐40 is associated with hypertension incidence only among men. The study findings need to be further verified by prospective cohort studies or clinical trials.

Perinatal Resveratrol Supplementation to Spontaneously Hypertensive Rat Dams Mitigates the Development of Hypertension in Adult Offspring

This study was undertaken to determine whether perinatal maternal resveratrol (Resv)--a phytoalexin known to confer cardiovascular protection--could prevent the development of hypertension and improve vascular function in adult spontaneously hypertensive rat offspring. Dams were fed either a control or Resv-supplemented diet (4 g/kg diet) from gestational day 0.5 until postnatal day 21. Indwelling catheters were used to assess blood pressure and vascular function in vivo; wire myography was used to assess vascular reactivity ex vivo. Perinatal Resv supplementation in dams had no effect on fetal body weights, albeit continued maternal treatment postnatally resulted in growth restriction in offspring by postnatal day 21; growth restriction was no longer evident after 5 weeks of age. Maternal perinatal Resv supplementation prevented the onset of hypertension in adult offspring (-18 mm Hg; P=0.007), and nitric oxide synthase inhibition (with L-NG-nitroarginine methyl ester) normalized these blood pressure differences, suggesting improved nitric oxide bioavailability underlies the hemodynamic alterations in the Resv-treated offspring. In vivo and ex vivo, vascular responses to methylcholine were not different between treatment groups, but prior treatment with L-NG-nitroarginine methyl ester attenuated the vasodilation in untreated, but not Resv-treated adult offspring, suggesting a shift toward nitric oxide-independent vascular control mechanisms in the treated group. Finally, bioconversion of the inactive precursor big endothelin-1 to active endothelin-1 in isolated mesenteric arteries was reduced in Resv-treated offspring (-28%; P<0.05), and this difference could be normalized by L-NG-nitroarginine methyl ester treatment. In conclusion, perinatal maternal Resv supplementation mitigated the development of hypertension and causes persistent alterations in vascular responsiveness in spontaneously hypertensive rats.

The Utility of Cerebral Blood Flow as a Biomarker of Preclinical Alzheimer's Disease

There is accumulating evidence suggesting that changes in brain perfusion are present long before the clinical symptoms of Alzheimer's disease (AD), perhaps even before amyloid-β accumulation or brain atrophy. This evidence, consistent with the vascular hypothesis of AD, implicates cerebral blood flow (CBF) in the pathogenesis of AD and suggests its utility as a biomarker of preclinical AD. The extended preclinical phase of AD holds particular significance for disease modification, as treatment would likely be most effective in this early asymptomatic stage of disease. This highlights the importance of identifying reliable and accurate biomarkers of AD that can differentiate normal aging from preclinical AD prior to clinical symptom manifestation. Cerebral perfusion, as measured by arterial spin labeling magnetic resonance imaging (ASL-MRI), has been shown to distinguish between normal controls and adults with AD. In addition to demonstrating diagnostic utility, CBF has shown usefulness as a tool for identifying those who are at risk for AD and for predicting subtle cognitive decline and conversion to mild cognitive impairment and AD. Taken together, this evidence not only implicates CBF as a useful biomarker for tracking disease severity and progression, but also suggests that ASL-measured CBF may be useful for identifying candidates for future AD treatment trials, especially in the preclinical, asymptomatic phases of the disease.

Impaired cardiac autonomic nervous system function is associated with pediatric hypertension independent of adiposity

BACKGROUND

We examined whether sympathetic nervous system activity influences hypertension status and systolic blood pressure (SBP) independent of adiposity in youth ranging from normal-weight to severe obesity.

METHODS

We examined the association of heart rate variability (HRV) with hypertension status and SBP among youth (6-18 y old; n = 188; 103 female). Seated SBP was measured using an automated cuff. Prehypertension (SBP percentile ≥ 90th to <95th) and hypertension (SBP percentile ≥ 95th) were defined by age-, sex-, and height-norms. Autonomic nervous system activity was measured using HRV via SphygmoCor MM3 system and analyzed for time- and frequency-domains. Total body fat was measured via dual-energy X-ray absorptiometry.

RESULTS

Logistic regression models demonstrated lower values in each time-domain HRV measure and larger low-frequency (LF):high-frequency (HF) ratio to be significantly associated with higher odds of being prehypertensive/hypertensive (11-47% higher odds) independent of total body fat (P < 0.05). In linear regression analysis, lower time-domain, but not frequency-domain, HRV measures were significantly associated with higher SBP independent of total body fat (P < 0.05).

CONCLUSION

These data suggest that impaired cardiac autonomic nervous system function, at rest, is associated with higher odds of being prehypertensive/hypertensive and higher SBP which may be independent of adiposity in youth.

Association Between High Serum Soluble Corin and Hypertension: A Cross-Sectional Study in a General Population of China

BACKGROUND

Corin has been suggested to be associated with hypertension by cell- and animal-based studies. However, the association still lacks population-based evidence which critically promotes translation from basic research to clinical and preventive practice. Here, we aimed to explore the association in a general population of China.

METHODS

From January to May 2010, we conducted a cross-sectional study in 2,498 participants aged above 30 years, residing in Gusu district of Suzhou. Serum soluble corin and blood pressure were measured.

RESULTS

Hypertensive participants had a higher level of serum corin than nonhypertensive participants (median (interquartile range): 1,836.83 (1,497.85-2,327.87) pg/ml vs. 1,579.14 (1,322.18-1,956.82) pg/ml, P < 0.001). Higher serum corin was positively associated with prevalent hypertension (odds ratio (OR) = 2.01, P < 0.001). In the multiple analysis, participants in the third (OR = 1.43, P = 0.007) and fourth (OR = 1.96, P < 0.001) quartiles had significantly increased odds of hypertension compared to those in the lowest quartile of serum corin. ORs of hypertension positively and significantly increased with serum corin levels (P for trend <0.001). Further subgroup analysis showed that ORs of hypertension associated with high corin (over the median level of serum corin: 1,689.20 pg/ml) were still significant in subgroups by age, body mass index, total cholesterol, low-density lipoprotein cholesterol, and fasting plasma glucose (all P < 0.05).

CONCLUSIONS

Our study showed that hypertensive participants had an increased serum corin level compared to those without hypertension. This finding suggests that corin may play a role in the pathology of hypertension.

Surgical Treatment of Cervical Spondylotic Myelopathy Associated Hypertension--A Retrospective Study of 309 Patients

Hypertension is the most prevalent cardiovascular disease, and various risk factors are known to be involved in it. Cervical spondylotic myelopathy (CSM) is the most common non-traumatic cause of myelopathy, which displays neurological symptoms and may induce systemic symptoms. To date, it is still unknown whether CSM is associated with hypertension, and if so, whether the decompression operations can attenuate CSM associated hypertension. Here, a total of 309 patients with CSM who received anterior or posterior decompression surgery were enrolled as subjects. Blood pressure measurements were performed before and within one week after the surgery. Among the 309 subjects, 144 (46.6%) of them exhibited hypertension before surgery, a significantly higher ratio than that of the whole population. One week after surgery, blood pressure of 106 (73.6%) patients turned back to normal. Blood pressure of another 37(25.7%) patients decreased with different degrees, although still higher than normal. Moreover, it appears that both approaches were effective in improving blood pressure, while the posterior approach was more effective in decreasing systolic blood pressure. We speculate this type of hypertension might result from hyperactivity of sympathetic nervous system as the heart rate of these patients decreased after surgery as well. Collectively, compression of spinal cord in CSM patients might be associated with hypertension, and decompression surgery largely attenuated this type of hypertension. These findings prove CSM to be a potential associated factor of high blood pressure and may shed light on therapies of hypertension in clinics.

Inhibition of the Prostaglandin Transporter PGT Lowers Blood Pressure in Hypertensive Rats and Mice

Inhibiting the synthesis of endogenous prostaglandins with nonsteroidal anti-inflammatory drugs exacerbates arterial hypertension. We hypothesized that the converse, i.e., raising the level of endogenous prostaglandins, might have anti-hypertensive effects. To accomplish this, we focused on inhibiting the prostaglandin transporter PGT (SLCO2A1), which is the obligatory first step in the inactivation of several common PGs. We first examined the role of PGT in controlling arterial blood pressure blood pressure using anesthetized rats. The high-affinity PGT inhibitor T26A sensitized the ability of exogenous PGE₂ to lower blood pressure, confirming both inhibition of PGT by T26A and the vasodepressor action of PGE₂ T26A administered alone to anesthetized rats dose-dependently lowered blood pressure, and did so to a greater degree in spontaneously hypertensive rats than in Wistar-Kyoto control rats. In mice, T26A added chronically to the drinking water increased the urinary excretion and plasma concentration of PGE₂ over several days, confirming that T26A is orally active in antagonizing PGT. T26A given orally to hypertensive mice normalized blood pressure. T26A increased urinary sodium excretion in mice and, when added to the medium bathing isolated mouse aortas, T26A increased the net release of PGE₂ induced by arachidonic acid, inhibited serotonin-induced vasoconstriction, and potentiated vasodilation induced by exogenous PGE₂. We conclude that pharmacologically inhibiting PGT-mediated prostaglandin metabolism lowers blood pressure, probably by prostaglandin-induced natriuresis and vasodilation. PGT is a novel therapeutic target for treating hypertension.

Association of alpha-ADD1 Gene and Hypertension Risk: A Meta-Analysis

Background

Results regarding the association between α-adducin (ADD1) gene and essential hypertension (EH) risk remain inconsistent. Therefore, we performed this meta-analysis to investigate this association.

Material/Methods

We comprehensively searched published literature from PubMed and Embase. All studies analyzing the association between ADD1 Gly460Trp polymorphism and EH risk were included. Fixed- or random-effects model was used to calculate pooled odds ratio (OR) with 95% confidence interval (CI).

Results

Data synthesis showed an increased risk of EH in T allele variant carriers with Asian descent, for GG vs. TT (OR=0.750, 95%CI: 0.585–0.960; P=0.022), recessive model (OR=1.196, 95%CI: 1.009–1.418; P=0.039), dominant model (OR=0.826, 95%CI: 0.693–0.985; P=0.033), and allelic model (OR=0.859, 95%CI: 0.756–0.964; P=0.01), respectively. However, no statistical differences were observed in Blacks and Caucasians.

Conclusions

The findings showed the association of the T allele in ADD1 gene with EH susceptibility in Asians. However, well-designed studies involving gene-gene and gene-environment interactions should be considered in future.

Systemic and renal oxidative stress in the pathogenesis of hypertension: modulation of long-term control of arterial blood pressure by resveratrol

Hypertension affects over 25% of the global population and is associated with grave and often fatal complications that affect many organ systems. Although great advancements have been made in the clinical assessment and treatment of hypertension, the cause of hypertension in over 90% of these patients is unknown, which hampers the development of targeted and more effective treatment. The etiology of hypertension involves multiple pathological processes and organ systems, however one unifying feature of all of these contributing factors is oxidative stress. Once the body's natural anti-oxidant defense mechanisms are overwhelmed, reactive oxygen species (ROS) begin to accumulate in the tissues. ROS play important roles in normal regulation of many physiological processes, however in excess they are detrimental and cause widespread cell and tissue damage as well as derangements in many physiological processes. Thus, control of oxidative stress has become an attractive target for pharmacotherapy to prevent and manage hypertension. Resveratrol (trans-3,5,4'-Trihydroxystilbene) is a naturally occurring polyphenol which has anti-oxidant effects in vivo. Many studies have shown anti-hypertensive effects of resveratrol in different pre-clinical models of hypertension, via a multitude of mechanisms that include its function as an anti-oxidant. However, results have been mixed and in some cases resveratrol has no effect on blood pressure. This may be due to the heavy emphasis on peripheral vasodilator effects of resveratrol and virtually no investigation of its potential renal effects. This is particularly troubling in the arena of hypertension, where it is well known and accepted that the kidney plays an essential role in the long term regulation of arterial pressure and a vital role in the initiation, development and maintenance of chronic hypertension. It is thus the focus of this review to discuss the potential of resveratrol as an anti-hypertensive treatment via amelioration of oxidative stress within the framework of the fundamental physiological principles of long term regulation of arterial blood pressure.

Correlation between cystathionine β-synthase T883C genetic polymorphism and primary hypertension

The present study aimed to investigate the correlation between cystathionine β-synthase (CBS) T833C polymorphisms and primary hypertension. A case-control study was conducted by genotyping the representative variation in 545 hypertensive individuals (aged 49.23±7.56 years) and 500 normotensive individuals (aged 49.90±10.01 years). The T833C genetic polymorphisms of the CBS enzyme were detected in all subjects by amplification refractory mutation system polymerase chain reaction (PCR) analysis. The CBS T833C polymorphism was successfully genotyped in the general population with a sample size of 1,045 (545+500) individuals. The genotypic and allelic frequency distributions of the CBS T833C polymorphism were not significantly different between the hypertensive and normotensive groups (P>0.05). The CC genotype was significantly different (P<0.05) from the CT and TT genotypes in terms of body mass index (BMI), and the levels of triglycerides (TG) and homocysteine (Hcy). Multiple logistic regression analysis revealed that BMI, total cholesterol (TC) level, smoking, plasma Hcy level and a family history of hypertension were the independent risk factors for hypertension in the population studied. The results indicate that the level of plasma Hcy was a risk factor for hypertension in the population studied. However, the mutation of the CBS T833C gene was not concluded to be an important hereditary factor for influencing the level of plasma Hcy.

Renal vasodilating capacity and endothelial function are impaired in patients with obstructive sleep apnea syndrome and no traditional cardiovascular risk factors

OBJECTIVE

Patients with obstructive sleep apnea syndrome exhibit accelerated vascular aging and renal damage. Aim of the study was to investigate whether vascular dysfunction is a feature of obstructive sleep apnea syndrome per se or instead related to the presence of traditional cardiovascular risk factors.

METHODS

Forty patients with moderate-severe obstructive sleep apnea syndrome (20 with, 20 without traditional risk factors) and 20 matched healthy controls were enrolled. Renal vasodilating capacity, endothelium-dependent vasodilation in the brachial artery, carotid-femoral pulse wave velocity and carotid stiffness were measured. Oxidative stress, endothelial biomarkers and leukocyte adhesion molecule levels were also evaluated.

RESULTS

Apneic patients without traditional cardiovascular risk factors presented reduced endothelium-dependent vasodilation (3.7±2.1 versus 6.1±3.0%, P<0.05), increased serum E-selectin (49.8±11.5 versus 38.9±17.9 ng/ml, P<0.05), and impaired renal vasodilating capacity (6.0±4.3 versus 10.4±6.1%, P<0.05), as compared to healthy controls. Endothelial NO synthase expression was reduced (0.0133 versus 0.0221×10 copies/μg RNA, P<0.05), whereas oxidative stress parameters and leukocyte adhesion molecules were similar to controls. Patients with obstructive sleep apnea syndrome and traditional risk factors also exhibit increased aortic and carotid stiffness, increased renal resistive index and intima-media thickness, and reduced expression of the endothelial progenitor cell marker CD34: however, these parameters were similar to those of healthy controls in patients with isolated obstructive sleep apnea syndrome.

CONCLUSION

Obstructive sleep apnea syndrome is characterized by endothelial dysfunction and activation and impaired renal vasodilating capacity even in the absence of traditional cardiovascular risk factors, possibly due to reduced endothelial NO synthase expression.

Blockade of endothelin ET(A), but not thromboxane, receptors offsets the cyclosporine-evoked hypertension and interrelated baroreflex and vascular dysfunctions

The impairment of arterial baroreceptor and vasodilator functions are two major contributors to the hypertensive action of cyclosporine (CSA). In this study, in vivo and in vitro pharmacological studies were performed to investigate whether these effects of CSA are differentially modulated by endothelin and thromboxane signaling. The treatment of rats with CSA (25mg/kg/day i.p.) for 7 consecutive days caused significant increases in blood pressure (BP), attenuated reflex heart rate (HR) responses to vasopressor (phenylephrine, PE) and vasodepressor (sodium nitroprusside, SNP) agents, and reduced cumulative vasorelaxant responses elicited by acetylcholine (Ach, 1×10(-9)-1×10(-5)M) in PE-precontracted isolated aortas. These effects of CSA were blunted after concurrent i.p. administration of atrasentan (selective ETA blocker, 10mg/kg/day), but not terutroban (thromboxane receptor blocker, 10mg/kg/day). Moreover, atrasentan reversed the reductions in aortic protein expression of eNOS caused by CSA whereas terutroban was without effect. We also report that the favorable effect of atrasentan on CSA-evoked impairment in aortic Ach responsiveness disappeared in rats treated simultaneously with L-NAME (NOS inhibitor, 10mg/kg/day) but not BQ 788 (ETB receptor blocker, 0.1mg/kg/day) or indomethacin (cycloxygenase inhibitor, 5mg/kg/day). Together, the data implicate endothelin ETA receptors in baroreflex and vascular derangements which predispose to the hypertensive effect of CSA. Moreover, the facilitation of NOS, but not ETB receptors or cycloxygenase-derived prostanoids, signaling is pivotal for advantageous effect of atrasentan on the aortic CSA-Ach interaction.

Ambulatory blood pressure monitoring in spinal cord injury: clinical practicability

Trauma to the spinal cord often results not only in sensorimotor but also autonomic impairments. The loss of autonomic control over the cardiovascular system can cause profound blood pressure (BP) derangements in subjects with spinal cord injury (SCI) and may therefore lead to increased cardiovascular disease (CVD) risk in this population. The use of ambulatory blood pressure monitoring (ABPM) allows insights into circadian BP profiles, which have been shown to be of good prognostic value for cardiovascular morbidity and mortality in able-bodied subjects. Past studies in SCI subjects using ABPM have shown that alterations in circadian BP patterns are dependent on the spinal lesion level. Tetraplegic subjects with sensorimotor complete lesions have a decreased daytime arterial BP, loss of the physiological nocturnal BP dip, and higher circadian BP variability, including potentially life-threatening hypertensive episodes known as autonomic dysreflexia (AD), compared with paraplegic and able-bodied subjects. The proposed underlying mechanisms of these adverse BP alterations mainly are attributed to a lost or decreased central drive to sympathetic spinal preganglionic neurons controlling the heart and blood vessels. In addition, several maladaptive anatomical changes within the spinal cord and the periphery, as well as the general decrease of physical daily activity in SCI subjects, account for adverse BP changes. ABPM enables the identification of adverse BP profiles and the associated increased risk for CVD in SCI subjects. Concurrently, it also might provide a useful clinical tool to monitor improvements of AD and lost nocturnal dip after appropriate treatments in the SCI population.

Lisinopril Indifferently Improves Heart Rate Variability During Day and Night Periods in Spontaneously Hypertensive Rats

The aim of this work was to investigate the effect of 10 weeks of lisinopril treatment to spontaneously hypertensive rats (SHRs) on day/night variations of blood pressure, heart rate and autonomic cardio-regulation parameters. Male SHR with surgically implanted radio-telemetry implant that provided direct measurements of arterial pressure and electrocardiogram wave were used. Animals were allocated to two groups (n=5 each). The first group was treated with lisinopril (20 mg/kg by gavage) daily for 10 weeks (treated group); whereas the second was gavaged daily with tap water (untreated group). Arterial blood pressure, ECG and other telemetry parameters were recorded at the start and at the end of 10-week treatment. Collected data were analyzed using specialized software and were statistically tested. In addition to the expected lowering of blood pressure, spectral analysis of R-R intervals revealed that lisinopril treatment for 10 weeks significantly caused 2-3 fold increase in heart rate variability (HRV) during both active and inactive periods. However, R-R interval durations demonstrated variable distribution patterns during those periods. The cause of observed distribution pattern of R-R intervals during active and inactive periods may be of significance to better understand HRV changes and warrants further investigations.

Resveratrol prevents hypertension and cardiac hypertrophy in hypertensive rats and mice

Resveratrol (RESV) is a polyphenol with pleiotropic effects that include reduction of oxidative stress and increased vascular nitric oxide (NO) production. However, whether or not RESV can prevent rises in blood pressure (BP) is controversial and remains to be firmly established. The purpose of this study was to determine whether RESV attenuates elevated BP and subsequent adaptive cardiac hypertrophy and to better understand the mechanisms involved. The spontaneously hypertensive rat (SHR) and the angiotensin (Ang)-II infused mouse were used as hypertensive models. Compared to a standard control diet, consumption of diets containing RESV by SHRs and Ang-II hypertensive mice, markedly prevented rises in systolic BP. In addition, flow-mediated vasodilation was significantly improved by RESV in SHRs. RESV also reduced serum and cardiac levels of the lipid peroxidation by-product, 4-hydroxy-2-nonenal in the hypertensive rodents and inhibited the production of superoxide in human-derived endothelial cells. Analysis of mesenteric arteries from SHRs and Ang-II infused mice demonstrated that RESV increased endothelial NO synthase (eNOS) phosphorylation by enhancing the LKB1/adenosine monophosphate (AMP)-activated protein kinase (AMPK) signal transduction pathway. Moreover, RESV reduced hypertrophic growth of the myocardium through reduced hemodynamic load and inhibition of the p70 S6 kinase pro-hypertrophic signaling cascade. Overall, we show that high dose RESV reduces oxidative stress, improves vascular function, attenuates high BP and prevents cardiac hypertrophy through the preservation of the LKB1-AMPK-eNOS signaling axis.

Altered regional blood flow distribution in Mas-deficient mice

BACKGROUND

We have recently shown that the acute infusion of angiotensin-(1-7) [Ang-(1-7)] or chronic increase in plasma Ang-(1-7) produces important changes in regional blood flow in rats.

METHODS

To further assess whether these changes are related to Mas, in this study hemodynamic measurements were performed in Ang-(1-7) receptor Mas knockout C57BL/6 (Mas-KO) mice and age-matched wild type (WT) control mice, using fluorescent microspheres.

RESULTS

Mean arterial pressure in urethane-anesthetized Mas-KO mice (12-16 weeks old) did not differ from that in WT mice (79 ± 2 and 80 ± 2 mmHg respectively). However, pronounced differences were observed in other hemodynamic measurements. Mas-KO mice exhibited a significant decrease in stroke volume (0.03 ± 0.01 versus 0.05 ± 0.01 ml/beat in WT) and decreased cardiac index (0.81 ± 0.08 versus 1.24 ± 0.24 ml/min/g in WT). Strikingly, Mas-KO mice exhibited a marked increase in vascular resistance and a decrease in blood flow in the kidney, lung, adrenal gland, mesentery, spleen and brown fat tissue. The decrease in blood flow ranged from 34% (spleen) to 55% (brown fat tissue).

CONCLUSION

These results suggest that the Ang-(1-7)/Mas axis plays an important role in regional and systemic hemodynamic adjustments in mice.

Hypertension in children and adolescents: epidemiology and pathogenesis

High blood pressure is one among the leading contributors to burden of disease globally. Approximately 54 % of stroke and 47 % of ischemic heart disease events worldwide were attributable to high blood pressure in the year 2001. There is deficiency of data on the long-term outcome of hypertension in children. In spite of this, there is sufficient evidence to suspect that the health risks of hypertension in pediatric patients are substantial. Hypertension in childhood is known to result in hypertension in young adulthood. The epidemiology of hypertension in children is well represented from various studies conducted across continents. Factors like methodological issues in measurement, socio demographic differences, adiposity levels and ethnicity appear to influence the distribution of blood pressure as well as prevalence of hypertension in children. The etio-pathogenesis of essential (primary) hypertension is multi-factorial in origin. Obesity, insulin resistance, activation of sympathetic nervous system, alterations in sodium homeostasis, renin-angiotensin system changes, changes in vascular smooth muscle structure and reactivity, high serum uric acid levels, genetic factors and fetal programming have been reported to contribute to this disorder. The causes of secondary hypertension vary with age. Renal disorders and coarctation of the aorta are the most common causes of hypertension in children up to age 6 y. In older children, renal parenchymal disease remains the most frequent cause of increased blood pressure. Other causes of hypertension in children are relatively rare and include systemic arteritis and certain tumours, endocrine dysfunction, and neurologic disorders.

Heart failure while on ventricular assist device support: a true clinical entity?

Ventricular assist devices (VADs) have become an established therapeutic option for patients with end-stage heart failure. The appearance of heart failure in VAD patients seems unexpected. Nevertheless, this phenomenon is not rare. We report six cases of VAD patients with clinical presentation of heart failure at different times after implantation and describe the mechanisms involved. The aetiology of this heart failure, like its clinical presentation, varies and has yet to be identified.

Therapeutic opportunities for targeting the ubiquitous cell surface receptor CD47

INTRODUCTION

CD47 is a ubiquitously expressed cell surface receptor that serves as a counter-receptor for SIRPα in recognition of self by the innate immune system. Independently, CD47 also functions as an important signaling receptor for regulating cell responses to stress.

AREAS COVERED

We review the expression, molecular interactions, and pathophysiological functions of CD47 in the cardiovascular and immune systems. CD47 was first identified as a potential tumor marker, and we examine recent evidence that its dysregulation contributes to cancer progression and evasion of anti-tumor immunity. We further discuss therapeutic strategies for enhancing or inhibiting CD47 signaling and applications of such agents in preclinical models of ischemia and ischemia/reperfusion injuries, organ transplantation, pulmonary hypertension, radioprotection, and cancer.

EXPERT OPINION

Ongoing studies are revealing a central role of CD47 for conveying signals from the extracellular microenvironment that limit cell and tissue survival upon exposure to various types of stress. Based on this key function, therapeutics targeting CD47 or its ligands thrombospondin-1 and SIRPα could have broad applications spanning reconstructive surgery, engineering of tissues and biocompatible surfaces, vascular diseases, diabetes, organ transplantation, radiation injuries, inflammatory diseases, and cancer.