Orthostatic hypotension and novel blood pressure-associated gene variants: Genetics of Postural Hemodynamics (GPH) Consortium

Transcriptome analysis reveals EBF1 ablation-induced injuries in cardiac system

Rationale: Regulatory processes of transcription factors (TFs) shape heart development and influence the adult heart's response to stress, contributing to cardiac disorders. Despite their significance, the precise mechanisms underpinning TF-mediated regulation remain elusive. Here, we identify that EBF1, as a TF, is highly expressed in human heart tissues. EBF1 is reported to be associated with human cardiovascular disease, but its roles are unclear in heart. In this study, we investigated EBF1 function in cardiac system. Methods: RNA-seq was utilized to profile EBF1 expression patterns. CRISPR/Cas9 was utilized to knock out EBF1 to investigate its effects. Human pluripotent stem cells (hPSCs) differentiated into cardiac lineages were used to mimic cardiac development. Cardiac function was evaluated on mouse model with Ebf1 knockout by using techniques such as echocardiography. RNA-seq was conducted to analyze transcriptional perturbations. ChIP-seq was employed to elucidate EBF1-bound genes and the underlying regulatory mechanisms. Results: EBF1 was expressed in some human and mouse cardiomyocyte. Knockout of EBF1 inhibited cardiac development. ChIP-seq indicated EBF1's binding on promoters of cardiogenic TFs pivotal to cardiac development, facilitating their transcriptional expression and promoting cardiac development. In mouse, Ebf1 depletion triggered transcriptional perturbations of genes, resulting in cardiac remodeling. Mechanistically, we found that EBF1 directly bound to upstream chromatin regions of cardiac hypertrophy-inducing genes, contributing to cardiac hypertrophy. Conclusions: We uncover the mechanisms underlying EBF1-mediated regulatory processes, shedding light on cardiac development, and the pathogenesis of cardiac remodeling. These findings emphasize EBF1's critical role in orchestrating diverse aspects of cardiac processes and provide a promising therapeutic intervention for cardiomyopathy.

Failure to Thrive in a Middle-Aged Female: A Case of Congenital Incomplete Pancreas From a Rare Genetic Defect

Hepatocyte nuclear factor-1 beta (HNF1B) gene is predominantly expressed in the liver, kidney, lung, genitourinary tract, and pancreas. It is an important transcription factor that regulates pancreas development. Mutation or absence of this gene is rare and can cause incomplete pancreatic development known as the agenesis of the dorsal pancreas. This rare genetic abnormality is associated with other disorders like maturity-onset diabetes of the young, abnormal liver function tests, genitourinary tract malformation, pancreatitis, and renal cysts. Diagnosing this genetic abnormality is difficult, especially in patients presenting with symptoms specific to only one system. Management is based on disease manifestation and involves a multidisciplinary approach. Our case describes a 51-year-old female with poorly controlled diabetes mellitus and Mullerian duct anomalies who presented with abdominal pain, fatigue, dizziness, and electrolyte derangement. Contrast-enhanced computed tomography (CECT) of the abdomen showed a multicystic kidney and a pancreatic head with a missing body and tail. Further workup revealed an HNF1B mutation.

A Nomogram model for predicting the occurrence of no-reflow phenomenon after percutaneous coronary intervention using the lncRNA TUG1/miR-30e/NPPB biomarkers

Background

Studies have shown that percutaneous coronary intervention (PCI) is considered as the essential therapeutic strategy for the patients with ST-segment elevation myocardial infarction (STEMI). However; no-reflow could still occur in a few patients after PCI. Studies have reported that biomarkers related to no-reflow pathogenetic components could play a prognostic role in the prediction phenomenon. Hence, this study explored the establishment of nomogram model for predicting the occurrence of no-reflow phenomenon after PCI using the lncRNA TUG1/miR-30e/NPPB biomarkers in patients with STEMI after PCI.

Methods

In this observational study, a total of 76 STEMI patients who underwent emergency PCI between January 2018 and December 2021were included. The patients after PCI, were divided into reflow (n=44) and no-reflow groups (n=32). The demographic, environmental and clinical risk factors were assessed and analysed between the groups. Quantitative RT-PCR was used to detect TUG1, miR-30e, and NPPB messenger RNA (mRNA) expression levels in the plasma of patients after PCI. Bioinformatic methods were used to predict the interaction of the plasma TUG1/miR-30e/NPPB axis. The risk factors in the no-reflow group were screened using a logistic-regression analysis, and a nomogram prediction model was constructed and validated. Subsequently, a gene set enrichment analysis revealed the function of lncRNA TUG1.

Results

Plasma lncRNA TUG1 and NPPB were more highly expressed and miR-30e was more lowly expressed in the no-reflow group than the normal-reflow group (P<0.001). A negative correlation was observed between lncRNA TUG1 and miR-30e, and between miR-30e and NPPB. However, a positive correlation was observed between lncRNA TUG1 and NPPB mRNA. The bioinformatics analysis predicted multiple binding sites on the lncRNA TUG1 and miR-30e. LncRNA TUG1 [odds ratio (OR): 0.163, 95% confidence interval (CI): 0.021–0.944] and hs-CRP (OR: 2.151, 95% CI: 1.536–3.974) found to be as independent predictors. The C-index of this prediction model was 0.982 (95% CI: 0.956–1.000).

Conclusions

TUG1 could function as an effective biomarker for no-reflow among patients with STEMI after PCT and the proposed nomogram may provide information for individualized treatment in patients with STEMI.

Cataloging the potential SNPs (single nucleotide polymorphisms) associated with quantitative traits, viz. BMI (body mass index), IQ (intelligence quotient) and BP (blood pressure): an updated review

Background

Single nucleotide polymorphism (SNP) variants are abundant, persistent and widely distributed across the genome and are frequently linked to the development of genetic diseases. Identifying SNPs that underpin complex diseases can aid scientists in the discovery of disease-related genes by allowing for early detection, effective medication and eventually disease prevention.

Main body

Various SNP or polymorphism-based studies were used to categorize different SNPs potentially related to three quantitative traits: body mass index (BMI), intelligence quotient (IQ) and blood pressure, and then uncovered common SNPs for these three traits. We employed SNPedia, RefSNP Report, GWAS Catalog, Gene Cards (Data Bases), PubMed and Google Scholar search engines to find relevant material on SNPs associated with three quantitative traits. As a result, we detected three common SNPs for all three quantitative traits in global populations: SNP rs6265 of the BDNF gene on chromosome 11p14.1, SNP rs131070325 of the SL39A8 gene on chromosome 4p24 and SNP rs4680 of the COMT gene on chromosome 22q11.21.

Conclusion

In our review, we focused on the prevalent SNPs and gene expression activities that influence these three quantitative traits. These SNPs have been used to detect and map complex, common illnesses in communities for homogeneity testing and pharmacogenetic studies. High blood pressure, diabetes and heart disease, as well as BMI, schizophrenia and IQ, can all be predicted using common SNPs. Finally, the results of our work can be used to find common SNPs and genes that regulate these three quantitative features across the genome.

Risk stratification of syncope: Current syncope guidelines and beyond

Syncope is an alarming event carrying the possibility of serious outcomes, including sudden cardiac death (SCD). Therefore, immediate risk stratification should be applied whenever syncope occurs, especially in the Emergency Department, where most dramatic presentations occur. It has long been known that short- and long-term syncope prognosis is affected not only by its mechanism but also by presence of concomitant conditions, especially cardiovascular disease. Over the last two decades, several syncope prediction tools have been developed to refine patient stratification and triage patients who need expert in-hospital care from those who may receive nonurgent expert care in the community. However, despite promising results, prognostic tools for syncope remain challenging and often poorly effective. Current European Society of Cardiology syncope guidelines recommend an initial syncope workup based on detailed patient's history, physical examination supine and standing blood pressure, resting ECG, and laboratory tests, including cardiac biomarkers, where appropriate. Subsequent risk stratification based on screening of features aims to identify three groups: high-, intermediate- and low-risk. The first should immediately be hospitalized and appropriately investigated; intermediate group, with recurrent or medium-risk events, requires systematic evaluation by syncope experts; low-risk group, sporadic reflex syncope, merits education about its benign nature, and discharge. Thus, initial syncope risk stratification is crucial as it determines how and by whom syncope patients are managed. This review summarizes the crucial elements of syncope risk stratification, pros and cons of proposed risk evaluation scores, major challenges in initial syncope management, and how risk stratification impacts management of high-risk/recurrent syncope.

Clinical Audit as a Quality Improvement Tool in Measurements of Lying and Standing Blood Pressure for Elderly Patients Admitted With a Hip Fracture

BACKGROUND

Around one in three adults aged 65 years and over will have a fall at home within a one-year period. Falls are estimated to cost the NHS more than £2.3 billion per year. The National Institute for Health & Care Excellence (NICE) guidelines recommend older people who present for medical attention because of a fall, report recurrent falls in the past year, or demonstrate abnormalities of gait and/or balance should be offered a multifactorial falls risk assessment which includes a cardiovascular examination and review of medications. Orthostatic hypotension (OH) is a common cardiovascular disorder, independently associated with an increased risk of falls in the elderly.

AIMS & OBJECTIVES

This study was carried out to assess improvement in lying and standing blood pressure (LSBP) measurement using clinical audit and staff education.

METHOD

An initial audit of patients over the age of 60, admitted with a hip fracture between the 14th of April and the 25th of May 2020 to assess measurement and accurate recording of LSBP. This cycle was followed by brainstorming, root cause analysis, teaching sessions for staff, and use of aide-memoires. A second audit cycle of patients was admitted with a hip fracture secondary to a fall between the 10th of August and the 21st of September 2020.

RESULT

 Our initial audit results showed 68% of patients who met the criteria in the NICE guidelines on measurement of LSBP were not being assessed for OH. Following interventions, the second audit cycle showed significant improvement in compliance, confirming audits to be a powerful tool in quality improvement programs.

The gut microbiota-related metabolite phenylacetylglutamine associates with increased risk of incident coronary artery disease

OBJECTIVE

The gut microbiota is increasingly being implicated in cardiovascular health. Metabolites produced by bacteria have been suggested to be mediators in the bacterial action on cardiovascular health. We aimed to identify gut microbiota-related plasma metabolites and test whether these metabolites associate with future risk of coronary artery disease (CAD).

METHODS

Nontargeted metabolomics was performed using liquid chromatography-mass spectrometry in order to measure 1446 metabolite features in the Malmö Offspring Study (MOS) (N = 776). The gut microbiota was characterized using 16S rRNA sequencing. Gut bacteria-related metabolites were measured in two independent prospective cohorts, the Malmö Diet and Cancer - Cardiovascular Cohort (MDC-CC) (N = 3361) and the Malmö Preventive Project (MPP) (N = 880), in order to investigate the associations between gut bacteria-related metabolites and risk of CAD.

RESULTS

In MOS, 33 metabolite features were significantly (P < 4.8e-7) correlated with at least one operational taxonomic unit. Phenylacetylglutamine (PAG) was associated with an increased risk of future CAD, using inverse variance weighted meta-analysis of age and sex-adjusted logistic regression models in MDC-CC and MPP. PAG remained significantly associated with CAD (OR = 1.17, 95% CI = 1.06-1.29, P = 1.9e-3) after adjustments for cardiovascular risk factors.

CONCLUSION

The levels of 33 plasma metabolites were correlated with the gut microbiota. Out of these, PAG was associated with an increased risk of future CAD independently of other cardiovascular risk factors. Our results highlight a link between the gut microbiota and CAD risk and should encourage further studies testing if modification of PAG levels inhibits development of CAD.

Hypertension in older persons: why one size does not fit all

Over recent years, managing hypertension in older people has gained increasing attention, with particular reference to very old, frailer individuals. In these patients, hypertension treatment may be challenging due to a higher risk of hypotension-related adverse events which commonly overlaps with a higher cardiovascular risk. Additionally, frailer older adults rarely satisfy inclusion criteria of randomized clinical trials, which determines a substantial lack of scientific data. Although limited, available evidence suggests that the association between blood pressure and adverse outcomes significantly varies at advanced age according to frailty status. In particular, the negative prognostic impact of hypertension seems to attenuate or even revert in individuals with older biological age, e.g. patients with disability, cognitive impairment, and poor physical performance. Consequently, one size doesn't fit all and personalized treatment strategies are needed, customized to individuals' frailty and functional status. Similar to other cardiovascular diseases, hypertension management in older people should be characterized by a geriatric approach based on biological rather than chronological age and a geriatric comprehensive evaluation including frailty assessment is required to provide the most appropriate treatment, tailored to patients' prognosis and health care goals. This review illustrates the importance of a patient-centered geriatric approach to hypertension management in older people with the final purpose to promote a wider implementation of frailty assessment in routine practice.

Nipping Adipocyte Inflammation in the Bud

Adipose tissue inflammation continues to represent a significant area of research in immunometabolism. We have identified a transcription factor, EBF1, which crucially regulates the expression of numerous inflammatory loci in adipocytes. However, EBF1 appears to do so without physically binding to these inflammatory genes. Our research is currently focused on understanding this discrepancy, and we believe that future findings could pave the road for drug development aimed to block adipose inflammation at its source.

Orthostatic Hypotension and Novel Blood Pressure Associated Gene Variants in Older Adults: Data From the TILDA Study

Orthostatic hypotension (OH) is associated with increased risk of trauma and cardiovascular events. Recent studies have identified new genetic variants that influence orthostatic blood pressure (BP). The aim of this study was to investigate the associations of candidate gene loci with orthostatic BP responses in older adults. A total of 3,430 participants aged ≥50 years from The Irish Longitudinal Study on Ageing (TILDA) with BP measures and genetic data from 12 single-nucleotide polymorphism (SNP) linked to BP responses were analyzed. Orthostatic BP responses were recorded at each 10 s interval and were defined as OH (SBP drop ≥20 mmHg or DBP drop ≥10 mmHg) at the time-points 40, 90, and 110 s. We defined sustained OH (SOH) as a drop that exceeded consensus BP thresholds for OH at 40, 90, and 110 s after standing. Logistic regression analyses modeled associations between the candidate SNP alleles and OH. We report no significant associations between OH and measured SNPs after correction for multiple comparisons apart from the SNP rs5068 where proportion of the minor allele was significantly different between cases and controls for SOH 40 (p = .002). After adjustment for covariates in a logistic regression, those with the minor G allele (compared to the A allele) had a decreased incidence rate ratio (IRR) for SOH 40 (IRR 0.45, p = .001, 95% CI 0.29-0.72). Only one SNP linked with increased natriuretic peptide concentrations was associated with OH. These results suggest that genetic variants may have a weak impact on OH but needs verification in other population studies.

Genomics of Cardiovascular Measures of Autonomic Tone

The autonomic nervous system exerts broad control over the involuntary functions of the human body through complex equilibrium between sympathetic and parasympathetic tone. Imbalance in this equilibrium is associated with a multitude of cardiovascular outcomes, including mortality. The cardiovascular static state of this equilibrium can be quantified using physiological parameters such as heart rate (HR), blood pressure, and by spectral analysis of HR variability. Here, we review the current state of knowledge of the genetic background of cardiovascular measurements of autonomic tone. For most parameters of autonomic tone, a large portion of variability is explained by genetic heritability. Many of the static parameters of autonomic tone have also been studied through candidate-gene approach, yielding some insight into how genotypes of adrenergic receptors affect variables such as HR. Genome-wide approaches in large cohorts similarly exist for static variables such as HR and blood pressure but less is known about the genetic background of the dynamic and more specific measurements, such as HR variability. Furthermore, because most autonomic measures are likely polygenic, pathway analyses and modeling of polygenic effects are critical. Future work will hopefully explain the control of autonomic tone and guide individualized therapeutic interventions.

Association of orthostatic hypertension with mortality in the Systolic Hypertension in the Elderly Program

We examined the association of orthostatic hypertension with all-cause mortality in the active treatment and placebo randomized groups of the Systolic Hypertension in the Elderly Program (SHEP). SHEP was a multicenter, randomized, double-blind, placebo-controlled clinical trial of the effect of chlorthalidone-based antihypertensive treatment on the rate of occurrence of stroke among older persons with isolated systolic hypertension (ISH). Men and women aged 60 years and above with ISH defined by a systolic blood pressure (SBP) of 160 mm Hg or higher and diastolic blood pressure lower than 90 mm Hg were randomized to chlorthalidone-based stepped care therapy or matching placebo. Among 4736 SHEP participants, 4073 had a normal orthostatic response, 203 had orthostatic hypertension, and 438 had orthostatic hypotension. Compared with normal response, orthostatic hypertension was associated with higher all-cause mortality at 4.5 and 17 years in analyses adjusted for age, gender, treatment, SBP, and pulse pressure (PP, HR 1.87, 95% CI 1.30–2.69, p = 0.0007; HR 1.40, 95% CI 1.17–1.68, p = 0.0003, respectively). These associations remained significant after additional adjustment for risk factors and comorbidities (HR 1.43, 95% CI 0.99–0.08, p = 0.0566 at 4.5 years, and HR 1.27, 95% CI 1.06–1.53, p = 0.0096 at 17 years). The increased risk of all-cause mortality associated with orthostatic hypertension was observed in both the active and placebo groups without significant interaction between randomization group and the effect on mortality. Orthostatic hypertension is associated with future mortality risk, is easily detected, and can be used in refining cardiovascular risk assessment.

Orthostatic hypotension: A review

Orthostatic hypotension, defined by a drop in blood pressure of at least 20mmHg for systolic blood pressure and at least 10mmHg for diastolic blood pressure within 3minutes of standing up, is a frequent finding, particularly in elderly patients. It is associated with a significant increase in morbidity and mortality. Although it is often multifactorial, the first favoring factor is medications. Other etiologies are divided in neurogenic orthostatic hypotension, characterized by autonomic failure due to central or peripheral nervous system disorders, and non-neurogenic orthostatic hypotension, mainly favoured by hypovolemia. Treatment always requires education of the patient regarding triggering situations and physiological countermanoeuvers. Pharmacological treatment may sometimes be necessary and mainly relies on volume expansion by fludrocortisone and/or a vasopressor agents such as midodrine. There is no predefined blood pressure target, the goal of therapy being the relief of symptoms and fall prevention.

Aortic atherosclerosis is a key modulator of the prognostic value of postural blood pressure changes

BACKGROUND AND AIMS

Orthostatic blood pressure decrease or increase has been related to cardiovascular events in hypertensive patients. Large blood pressure changes after orthostatic stress are associated with autonomic and neurohormonal abnormalities; aortic atherosclerosis (ATS) may also play a role.

METHODS

We investigated the interaction of ATS on the prognostic value of postural blood pressure changes. In a cohort of 958 hypertensive patients with an aortography (mean ± standard deviation age 44 ± 11 years, 61% men, mean blood pressure 182/110 mmHg), blood pressure was measured after 10 min of rest in the supine position. Systolic blood pressure (SBP) was also measured in standing position, 1 min after the supine position. Blood pressure changes were calculated as supine SBP minus standing SBP and analyzed as absolute or arithmetic means. ATS was assessed using an aortography score.

RESULTS

After 15 years of follow-up, 280 all-cause and 167 cardiovascular deaths occurred. In a multivariable Cox regression analysis adjusted for major cardiovascular risk factors and stratified according to ATS status, SBP changes were statistically associated with all-cause and cardiovascular mortality only in the presence of ATS: tertile 3 versus 1, 2.99 (1.37-6.49) and 4.08 (1.55-10.72) respectively, tertile 3 versus 2, 2.89 (1.29-6.46) and 4.82 (1.79-12.98), respectively (p for interaction: 0.003 for all-cause and 0.003 for cardiovascular mortality) for absolute changes. The hazard associated with the magnitude of SBP changes was more important than that associated with its direction.

CONCLUSIONS

The prognostic significance of postural SBP changes is markedly influenced by ATS in hypertensive patients.

Altered Venous Function during Long-Duration Spaceflights

Aims: Venous adaptation to microgravity, associated with cardiovascular deconditioning, may contribute to orthostatic intolerance following spaceflight. The aim of this study was to analyze the main parameters of venous hemodynamics with long-duration spaceflight.

Methods: Venous plethysmography was performed on 24 cosmonauts before, during, and after spaceflights aboard the International Space Station. Venous plethysmography assessed venous filling and emptying functions as well as microvascular filtration, in response to different levels of venous occlusion pressure. Calf volume was assessed using calf circumference measurements.

Results: Calf volume decreased during spaceflight from 2.3 ± 0.3 to 1.7 ± 0.2 L (p < 0.001), and recovered after it (2.3 ± 0.3 L). Venous compliance, determined as the relationship between occlusion pressure and the change in venous volume, increased during spaceflight from 0.090 ± 0.005 to 0.120 ± 0.007 (p < 0.01) and recovered 8 days after landing (0.071 ± 0.005, arbitrary units). The index of venous emptying rate decreased during spaceflight from −0.004 ± 0.022 to −0.212 ± 0.033 (p < 0.001, arbitrary units). The index of vascular microfiltration increased during spaceflight from 6.1 ± 1.8 to 10.6 ± 7.9 (p < 0.05, arbitrary units).

Conclusion: This study demonstrated that overall venous function is changed during spaceflight. In future, venous function should be considered when developing countermeasures to prevent cardiovascular deconditioning and orthostatic intolerance with long-duration spaceflight.

Association of CYP17A1 Genetic Polymorphisms and Susceptibility to Essential Hypertension in the Southwest Han Chinese Population

Background

The CYP17A1 gene encodes for cytochrome P450 enzyme CYP17A1, which is involved with the steroidogenic pathway including mineralocorticoids. The CYP17A1 polymorphisms might affect enzyme activity, then leading to a state of mineralocorticoid 11-deoxycorticosterone excess characterized by hypertension, suppressed plasma renin activity, and low aldosterone concentrations. The aim of this study was to investigate the contribution of CYP17A1 polymorphisms in inducing the susceptibility to essential hypertension among the Southwest Han Chinese population.

Material/Methods

Eight single nucleotide polymorphisms of CYP17A1 were genotyped in a case-control study for samples by polymerase chain reaction-restriction fragment length polymorphism analysis.

Results

The polymorphisms rs11191548 and rs4919687 were significantly associated with hypertension risk, which was confirmed by systolic and diastolic blood pressure distribution analyses between different genotype groups, and these two polymorphisms were found in linkage disequilibrium. The rs4919687 polymorphism was estimated to cause the destruction of exonic splicing silencer (ESR and Motif 3) sites and to transform the transcription factor AREB6 binding site, respectively, in the bioinformatics analyses. The haplotypes rs4919686A-rs3740397G -rs4919687C-rs743572C-rs11191548C and rs4919686A-rs3740397G-rs4919687T-rs743572C- rs11191548T were found to be susceptible to essential hypertension.

Conclusions

Our findings suggest that the CYP17A1 polymorphisms could be a genetic risk factor for essential hypertension among the Yunnan Han Chinese population, which would have implications for the treatment of this complex disorder.

Replication of Early B-cell Factor 1 (EBF1) Gene-by-psychosocial Stress Interaction Effects on Central Adiposity in a Korean Population

Objectives

Central obesity plays a major role in the development of many chronic diseases, including cardiovascular disease and cancer. Chronic stress may be involved in the pathophysiology of central obesity. Although several large-scale genome-wide association studies have reported susceptibility genes for central adiposity, the effects of interactions between genes and psychosocial stress on central adiposity have rarely been examined. A recent study focusing on Caucasians discovered the novel gene early B-cell factor 1 (EBF1), which was associated with central obesity-related traits via interactions with stress levels. We aimed to evaluate EBF1 gene-by-stress interaction effects on central adiposity traits, including visceral adipose tissue (VAT), in Korean adults.

Methods

A total of 1467 Korean adults were included in this study. We selected 22 single-nucleotide polymorphisms (SNPs) in the EBF1 gene and analyzed their interactions with stress on central adiposity using additive, dominant, and recessive genetic modeling.

Results

The four SNPs that had strong linkage disequilibrium relationships (rs10061900, rs10070743, rs4704967, and rs10056564) demonstrated significant interactions with the waist-hip ratio in the dominant model (p_int<0.007). In addition, two other SNPs (rs6556377 and rs13180086) were associated with VAT by interactions with stress levels, especially in the recessive genetic model (p_int<0.007). As stress levels increased, the mean values of central adiposity traits according to SNP genotypes exhibited gradual but significant changes (p<0.05).

Conclusions

These results suggest that the common genetic variants for EBF1 are associated with central adiposity through interactions with stress levels, emphasizing the importance of managing stress in the prevention of central obesity.

Orthostatic Hypotension and Elevated Resting Heart Rate Predict Low-Energy Fractures in the Population: The Malmö Preventive Project

Background

Autonomic disorders of the cardiovascular system, such as orthostatic hypotension and elevated resting heart rate, predict mortality and cardiovascular events in the population. Low-energy-fractures constitute a substantial clinical problem that may represent an additional risk related to such autonomic dysfunction.

Aims

To test the association between orthostatic hypotension, resting heart rate and incidence of low-energy-fractures in the general population.

Methods and Results

Using multivariable-adjusted Cox regression models we investigated the association between orthostatic blood pressure response, resting heart rate and first incident low-energy-fracture in a population-based, middle-aged cohort of 33 000 individuals over 25 years follow-up.

The median follow-up time from baseline to first incident fracture among the subjects that experienced a low energy fracture was 15.0 years. A 10 mmHg orthostatic decrease in systolic blood pressure at baseline was associated with 5% increased risk of low-energy-fractures (95% confidence interval 1.01–1.10) during follow-up, whereas the resting heart rate predicted low-energy-fractures with an effect size of 8% increased risk per 10 beats-per-minute (1.05–1.12), independently of the orthostatic response. Subjects with a resting heart rate exceeding 68 beats-per-minute had 18% (1.10–1.26) increased risk of low-energy-fractures during follow-up compared with subjects with a resting heart rate below 68 beats-per-minute. When combining the orthostatic response and resting heart rate, there was a 30% risk increase (1.08–1.57) of low-energy-fractures between the extremes, i.e. between subjects in the fourth compared with the first quartiles of both resting heart rate and systolic blood pressure-decrease.

Conclusion

Orthostatic blood pressure decline and elevated resting heart rate independently predict low-energy fractures in a middle-aged population. These two measures of subclinical cardiovascular dysautonomia may herald increased risks many years in advance, even if symptoms may not be detectable. Although the effect sizes are moderate, the easily accessible clinical parameters of orthostatic blood pressure response and resting heart rate deserve consideration as new risk predictors to yield more accurate decisions on primary prevention of low-energy fractures.

Recent Advances in the Genetics of Hypertension

Hypertension is a silent killer worldwide, caused by both genetic and environmental factors. Until now, genetic and genomic association studies of hypertension are reporting different degree of association on hypertension. Hence, it is essential to gather all the available information on the reported genetic loci and to determine if any biomarker(s) is/are significantly associated with hypertension. Current review concluded the potential biomarkers for hypertension, with regards to electrolyte and fluid transports, as well as sodium/potassium ions homeostasis, which are supported by the results of case-controls and meta-analyses.

Orthostatic hypotension and orthostatic hypertension in American veterans

PURPOSE

Abnormal blood pressure (BP) response to orthostatic maneuvers may predict adverse health outcomes. Orthostatic hypotension (OH) is defined as a fall in BP of ≥20/10 mmHg, and orthostatic hypertension (OHTN) is defined as an increase in systolic BP (SBP) of ≥20 mmHg, with standing. Herein, we document the prevalence of OH and OHTN in American veterans.

METHODS

The influence of demographic characteristics, life habits, co-incident medical conditions, and prescription medication use on these prevalence rates and associations between abnormal orthostatic BP responses and severity of self-reported symptoms of fatigue, dizziness, trouble concentrating, and head and neck discomfort were determined.

RESULTS

286 veterans participated; 14 % were classified with OH, 22 % with OHTN, and 64 % with normal BP responses to standing (reference group). An increased prevalence of the diagnosis of diabetes mellitus (27 %) and hypertension (63 %) was noted, which did not differ by orthostatic BP classification. Veterans with OH were older than the reference group and were prescribed more antihypertensive medications than the reference and OHTN groups. While the prevalence of OH increased with age, the prevalence of OHTN was comparable in young (20-30 years) and old (70+ years) veterans (17 vs. 19 %, respectively). The severity of fatigue and dizziness was increased in veterans with OH and OHTN compared to the reference group.

CONCLUSION

These data suggest a relatively high prevalence of OH and OHTN, which is associated with increased self-reported severity of fatigue and dizziness in American veterans, findings which may adversely impact long-term health outcomes.

Correlation between rs198388 and rs198389 polymorphismsin brainnatriuretic peptide (NPPB) gene and susceptibility to congenital heart diseases in a Chinese population

OBJECTIVE

We discussed the correlation between SNP loci (rs198389 and rs198388) in brain natriuretic peptide gene (NPPB) and susceptibility to congenital heart diseases (CHD).

METHOD

Multiplex SNaPshot technique was adopted for profiling of SNP genotypes at loci rs198389 and rs198388 in NPPB gene among 150 cases of CHDand 150 normal controls.

RESULTS

The distribution frequency of 3 genotypes (AA, AG and GG) at locus rs198389 was 40.7%, 36.0% and 23.3% in CHD group, respectively, showing significant differences compared with the normal controls (P<0.001). Gallele was associated with higher risk of CHD (OR=2.48, 95% CI=1.77-3.48). The distribution frequency of CC, CTand TT genotypes at locus rs198388 was 60.7%, 17.3% and 22.0% in CHD group, respectively, also showing significant differences compared with the normal controls (P<0.001). C allele could increase the risk of CHD (OR=1.92, 95% CI=1.48-2.48).

CONCLUSION

SNP loci rs198389 and rs198388 in NPPB gene were correlated with genetic susceptibility to CHD.

Orthostatic Changes in Hemodynamics and Cardiovascular Biomarkers in Dysautonomic Patients

Background

Impaired autonomic control of postural homeostasis results in orthostatic intolerance. However, the role of neurohormones in orthostatic intolerance has not been explained.

Methods

Six-hundred-and-seventy-one patients (299 males; 55±22 years) with unexplained syncope underwent head-up tilt (HUT) with serial blood sampling. Systolic blood pressure (SBP) and heart rate (HR) supine, after 3min, and lowest BP/highest HR during HUT were recorded. Plasma levels of epinephrine, norepinephrine, renin, C-terminal-pro-arginine-vasopressin (CT-proAVP), C-terminal- endothelin-1 (CT-proET-1), and mid-regional-fragment of pro-atrial-natriuretic-peptide (MR-proANP) were determined at supine and 3min of HUT. Multivariate-adjusted logistic regression model was applied to compare 1^st (reference) with 4^th quartile of 3 min and maximal ΔSBP/ΔHR (i.e. pronounced hypotension or tachycardia) vs. changes in neuroendocrine biomarkers, respectively.

Results

Higher resting CT-proET-1 predicted BP fall at 3min (Odds ratio (OR) per 1 SD: 1.62, 95%CI 1.18–2.22; p = 0.003), and max BP fall during HUT (1.82, 1.28–2.61; p = 0.001). Higher resting CT-proAVP predicted BP fall at 3min (1.33, 1.03–1.73; p = 0.03), which was also associated with increase in CT-proAVP (1.86, 1.38–2.51; p = 0.00005) and epinephrine (1.47, 1.12–1.92; p = 0.05) during HUT. Lower resting MR-proANP predicted tachycardia at 3min (0.37, 0.24–0.59; p = 0.00003), and max tachycardia during HUT (0.47, 0.29–0.77; p = 0.002). Further, tachycardia during HUT was associated with increase in epinephrine (1.60, 1.15–2.21; p = 0.005), and norepinephrine (1.87, 1.38–2.53; p = 0.005).

Conclusions

Resting CT-proET-1 and CT-proAVP are increased in orthostatic hypotension, while resting MR-proANP is decreased in postural tachycardia. Moreover, early BP fall during orthostasis evokes increase in CT-proAVP and epinephrine, while postural tachycardia is associated with increase in norepinephrine and epinephrine.

Relation between blood pressure and mortality risk in an older population: role of chronological and biological age

BACKGROUND

The relation between high blood pressure (BP) and mortality risk in older individuals (above 65 years of age) is still debated. Some data suggest that this relation is inverted in certain subgroups of (biologically) older individuals. We therefore investigated whether the association between BP and mortality is dependent on chronological age and on physical and cognitive function as indicators of biological age.

METHODS

The relationship between BP and all-cause mortality was investigated in 1466 older participants (aged 65 years and older; mean age 75.8 years) of the Longitudinal Ageing Study Amsterdam using multiple adjusted Cox proportional hazard models. Analyses were stratified for age, gait speed and mini mental state examination score.

RESULTS

A total of 1008 participants died after a median (range) follow-up of 10.6 (0.2; 15.9) years. Low diastolic blood pressure (DBP) was associated with an increased all-cause mortality risk: hazard ratio (HR) of low DBP (≤70 mmHg) compared to normal DBP (71-90 mmHg) was 1.36 [95% confidence interval (CI) 1.15; 1.61]. This relation was particularly strong in the oldest old (individuals aged >80 years) and in those who had lower levels of both physical and cognitive functioning: HRs (95% CIs) of low versus normal DBP were 1.58 (1.26; 1.98) and 1.45 (1.18; 1.77), respectively.

CONCLUSION

In a large population-based cohort of older adults, low DBP was associated with an increased all-cause mortality risk, especially in the oldest old and in biologically old individuals.

Current concepts in orthostatic hypotension management

Orthostatic hypotension is a condition commonly affecting the elderly and is often accompanied by disabling presyncopal symptoms, syncope and impaired quality of life. The pathophysiology of orthostatic hypotension is linked to abnormal blood pressure regulatory mechanisms and autonomic insufficiency. As part of its diagnostic evaluation, a comprehensive history and medical examination focused on detecting symptoms and physical findings of autonomic neuropathy should be performed. In individuals with substantial falls in blood pressure upon standing, autonomic function tests are recommended to detect impairment of autonomic reflexes. Treatment should always follow a stepwise approach with initial use of nonpharmacologic interventions including avoidance of hypotensive medications, high-salt diet and physical counter maneuvers. If these measures are not sufficient, medications such as fludrocortisone and midodrine can be added. The goals of treatment are to improve symptoms and to make the patient as ambulatory as possible instead of targeting arbitrary blood pressure values.

Orthostatic hypotension and incident heart failure in community-dwelling older adults

OBJECTIVES

To examine the association of orthostatic hypotension with incident heart failure (HF) in older adults.

METHODS

Of the 5,273 community-dwelling adults aged 65 years and older free of baseline prevalent HF in the Cardiovascular Health Study, 937 (18%) had orthostatic hypotension, defined as ≥20 mmHg drop in systolic or ≥10 mmHg drop in diastolic blood pressure from supine to standing position at 3 minutes. Of the 937, 184 (20%) had symptoms of dizziness upon standing and were considered to have symptomatic orthostatic hypotension. Propensity scores for orthostatic hypotension were estimated for each of the 5,273 participants and were used to assemble a cohort of 3,510 participants (883 participants with and 2,627 participants without orthostatic hypotension) who were balanced on 40 baseline characteristics. Cox regression models were used to estimate the association of orthostatic hypotension with centrally adjudicated incident HF and other outcomes during 13 years of follow-up.

RESULTS

Participants (n = 3,510) had a mean (±standard deviation) age of 74 (±6) years, 58% were women, and 15% nonwhite. Incident HF occurred in 25% and 21% of matched participants with and without orthostatic hypotension, respectively (hazard ratio, 1.24; 95% confidence interval, 1.06-1.45; p = .007). Among matched participants, hazard ratios for incident HF associated with symptomatic (n = 173) and asymptomatic (n = 710) orthostatic hypotension were 1.57 (95% confidence interval, 1.16-2.11; p = .003) and 1.17 (95% confidence interval, 0.99-1.39; p = .069), respectively.

CONCLUSIONS

Community-dwelling older adults with orthostatic hypotension have higher independent risk of developing new-onset HF, which appeared to be more pronounced in those with symptomatic orthostatic hypotension.

Pathophysiology of hypertension in the absence of nitric oxide/cyclic GMP signaling

The nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signaling system is a well-characterized modulator of cardiovascular function, in general, and blood pressure, in particular. The availability of mice mutant for key enzymes in the NO-cGMP signaling system facilitated the identification of interactions with other blood pressure modifying pathways (e.g. the renin-angiotensin-aldosterone system) and of gender-specific effects of impaired NO-cGMP signaling. In addition, recent genome-wide association studies identified blood pressure-modifying genetic variants in genes that modulate NO and cGMP levels. Together, these findings have advanced our understanding of how NO-cGMP signaling regulates blood pressure. In this review, we will summarize the results obtained in mice with disrupted NO-cGMP signaling and highlight the relevance of this pathway as a potential therapeutic target for the treatment of hypertension.

Syndromes of orthostatic intolerance: a hidden danger

Orthostatic hypotension (OH) is a relatively common heterogenous and multifactorial disorder, traditionally classified as neurogenic (less common but often more severe) or nonneurogenic (more common, with no direct signs of autonomic nervous system disease). The different clinical variants of orthostatic intolerance include initial, classical and delayed OH as well as postural tachycardia syndrome. Orthostatic instability may induce syncopal attacks either alone or in combination with other mechanisms, and is often dismissed as a precipitating factor. Moreover, prevalent OH is an independent risk factor for all-cause mortality and cardiovascular morbidity, and the majority of patients with OH are asymptomatic or have few nonspecific symptoms. Management of symptomatic orthostatic intolerance includes both nonpharmacological and pharmacological methods, but it is not always successful and may lead to complications. Future studies of OH should focus on mechanisms that lead to neurogenic and nonneurogenic OH, novel diagnostic methods and more effective therapeutic modalities.