N-terminal pro-brain natriuretic peptide and abnormal brain aging: The AGES-Reykjavik Study

Role of Cardiac Biomarkers in Stroke and Cognitive Impairment

This topical review assesses the growing role of cardiac biomarkers beyond cardiovascular health and focuses on their importance in stroke and dementia. The first part describes blood-based cardiac biomarkers in patients with stroke and highlights applications in the setting of early diagnosis, poststroke complications, outcome prediction as well as secondary prevention. Among other applications, natriuretic peptides can be helpful in differentiating stroke subtypes. They are also currently being investigated to guide prolonged ECG monitoring and secondary prevention in patients with stroke. Elevated cardiac troponin after ischemic stroke can provide information about various poststroke complications recently termed the stroke-heart syndrome. The second part focuses on the role of cardiac biomarkers in vascular cognitive impairment and dementia, emphasizing their association with structural brain lesions. These lesions such as silent brain infarcts and white matter hyperintensities often co-occur with cardiac disease and may be important mediators between cardiovascular disease and subsequent cognitive decline. ECG and echocardiogram measurements, in addition to blood-based biomarkers, show consistent associations with vascular brain changes and incident dementia, suggesting a role in indicating risk for cognitive decline. Together, the current evidence suggests that cardiac blood-based, electrophysiological, and imaging biomarkers can be used to better understand the heart and brain connection in the setting of not only stroke but also dementia.

The Mediating Role of Biomarkers in the Association Between Subjective Aging and Episodic Memory

OBJECTIVES

Subjective aging, indexed by subjective age and self-perceptions of aging (SPA), is consistently related to cognition in adulthood. The present study examined whether blood biomarkers mediate the longitudinal associations between subjective aging indices and memory.

METHODS

Data of 5,369 individuals aged 50-94 years (mean = 66.89 years, SD = 9.22; 60% women) were drawn from the Health and Retirement Study (HRS). Subjective age, SPA, and demographic factors were assessed in 2012/2014. Interleukin-6, C-reactive protein, albumin, cystatin C, N-terminal pro B-type natriuretic peptide (NT-proBNP), fasting glucose, Vitamin D, hemoglobin, red cells distribution width, and epigenetic aging were assessed as part of the HRS Venuous Blood Study in 2016. Memory was measured in 2018. The mediators (except for epigenetic aging, which was assessed in a subsample) were tested simultaneously in models that accounted for demographic covariates.

RESULTS

An older subjective age was related to worse memory partially through higher fasting glucose, higher cystatin C, higher NT-proBNP, and accelerated epigenetic aging. Negative SPA was related to worse memory through lower Vitamin D3, higher fasting glucose, higher cystatin C, higher NT-proBNP, and accelerated epigenetic aging. The biomarkers explained between 2% and 10% of subjective age and between 1% and 8% of SPA associations with memory. Additional analysis revealed that biomarkers continued to be significant mediators when physical inactivity and depressive symptoms were included as additional mediators.

CONCLUSION

The present study adds to existing research on the association between subjective aging and memory by providing new evidence on the biological mediators of this association.

Circulating cardiac biomarkers, structural brain changes, and dementia: Emerging insights and perspectives

Diseases of the heart and brain are strongly linked to each other, and cardiac dysfunction is associated with cognitive decline and dementia. This link between cardiovascular disease and dementia offers opportunities for dementia prevention through prevention and treatment of cardiovascular risk factors and heart disease. Increasing evidence suggests the clinical utility of cardiac biomarkers as risk markers for structural brain changes and cognitive impairment. We propose the hypothesis that structural brain changes are the link between impaired cardiac function, as captured by blood-based cardiac biomarkers, and cognitive impairment. This review provides an overview of the literature and illustrates emerging insights into the association of markers of hemodynamic stress (natriuretic peptides) and markers of myocardial injury (cardiac troponins) with imaging findings of brain damage and cognitive impairment or dementia. Based on these findings, we discuss potential pathophysiological mechanisms underlying the association of cardiac biomarkers with structural brain changes and dementia. We suggest testable hypotheses and a research plan to close the gaps in understanding the mechanisms linking vascular damage and neurodegeneration, and to pave the way for targeted effective interventions for dementia prevention. From a clinical perspective, cardiac biomarkers open the window for early identification of patients at risk of dementia, who represent a target population for preventive interventions targeting modifiable cardiovascular risk factors to avert cognitive decline and dementia.

Cognitive Dysfunction after Heart Disease: A Manifestation of the Heart-Brain Axis

The functions of the brain and heart, which are the two main supporting organs of human life, are closely linked. Numerous studies have expounded the mechanisms of the brain-heart axis and its related clinical applications. However, the effect of heart disease on brain function, defined as the heart-brain axis, is less studied even though cognitive dysfunction after heart disease is one of its most frequently reported manifestations. Hypoperfusion caused by heart failure appears to be an important risk factor for cognitive decline. Blood perfusion, the immune response, and oxidative stress are the possible main mechanisms of cognitive dysfunction, indicating that the blood-brain barrier, glial cells, and amyloid-β may play active roles in these mechanisms. Clinicians should pay more attention to the cognitive function of patients with heart disease, especially those with heart failure. In addition, further research elucidating the associated mechanisms would help discover new therapeutic targets to intervene in the process of cognitive dysfunction after heart disease. This review discusses cognitive dysfunction in relation to heart disease and its potential mechanisms.

The association between transthoracic echocardiogram parameters and white matter hyperintensities

OBJECTIVE

Identify abnormal cardiac chamber size and hemodynamic parameters on transthoracic echocardiogram (TTE) as predictors of advancing cerebral small vessel disease (CSVD) on brain magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A retrospective chart review of adults with a brain MRI and a 2-dimensional TTE was performed. WMH measured by the Fazekas score served as the primary outcome. We fit multivariate ordinal logistic regression models to the Fazekas score with the individual predictors of the TTE measurements and adjusted for potential confounders.

RESULTS

132 individuals were included. Cardiac functional markers were not significant, including tricuspid annular plane systolic excursion (p = 0.818), right ventricular ejection fraction (p = 0.818) and left ventricular ejection fraction (p = 0.673). Cardiac structural markers included right atrial area (p = 0.247), right ventricular internal diameter (RVID, p = 0.020) and left atrial area (LAA, p = 0.041). RVID and LAA were identified as being predictors, although the direction of the association suggested that normal values resulted in more WMH. Analysis of isolated DWM or PVWM Fazekas scores were not associated with cardiac structure or function.

CONCLUSIONS

In our study, we found that normal LAA and RVID values were associated with an increased degree of WMH on MRI. This finding may represent earlier identification of WMH prior to TTE cardiac changes. Future studies are needed for more robust quantitative comparison as well as evaluation prospectively of the association between cardiac chamber sizes and development of WMH.

Arterial Stiffness in Aging: Does It Have a Place in Clinical Practice?: Recent Advances in Hypertension

Aortic stiffness increases markedly with age and is associated with excess risk for various adverse clinical outcomes, including heart disease, dementia, and kidney disease. Although evidence for adverse effects of aortic stiffening is overwhelming, integration of direct and indirect measures of aortic stiffness into routine clinical assessment has lagged behind the science. This brief review will examine recent evidence supporting the value of stiffness as an important new risk factor for hypertension and cardiovascular disease and will offer suggestions for incorporating stiffness measures into routine clinical practice.

Systemic Inflammation and Cardio-Renal Organ Damage Biomarkers in Middle Age Are Associated With Physical Capability Up to 9 Years Later

Supplemental Digital Content is available in the text.

Background:

Physical capability, a key component of healthy aging, is associated with cardiovascular and other risk factors across life. We investigated whether midlife biomarkers of heart and kidney damage capturing the cumulative impact of long-term adverse exposures were associated with the level and decline in physical capability over 9 years of follow-up, taking account of systemic inflammatory biomarkers and conventional cardiovascular risk factors.

Methods:

We used data on 1736 men and women from the oldest British birth cohort study with walking speed, chair rise speed, balance time, and grip strength assessed at ages 60 to 64 and 69 years. We tested associations between logged and standardized measures of cystatin C, NT-proBNP (N-terminal pro-B-type natriuretic peptide), interleukin (IL)-6, and E-selectin at age 60 to 64 years with performance at age 69 years, adjusting for sex, height, and body mass index; then for performance at age 60 to 64 years. These biomarkers were mutually adjusted, and additionally adjusted for cardiovascular risk factors (pulse pressure, total/high density lipoprotein cholesterol, glycosylated hemoglobin), diabetes mellitus, cardiovascular and kidney disease, smoking status, and lifetime socioeconomic position.

Results:

Cystatin C, NT-proBNP, and IL-6 (but not E-selectin) were inversely associated with all outcomes, adjusted for sex, height, and body mass index. For example, a 1-SD increase in logged NT-proBNP was associated with weaker grip (−0.63 kg, 95% CI, −0.99 to −0.28); the equivalent association for cystatin C was −0.60 kg (95% CI, −0.94 to −0.25) and for IL-6 was −0.76 kg (95% CI, −1.11 to −0.41). Most associations remained, albeit attenuated, after adjustment for previous performance and mutual adjustment of the biomarkers. NT-proBNP and IL-6 (but not cystatin C) were more strongly associated with the outcomes than many of the conventional risk factors after mutual adjustment.

Conclusions:

Higher levels of NT-proBNP may identify those in midlife at risk of accelerated physical decline. Before considering the use of NT-proBNP for risk stratification, further research should untangle whether these associations exist because the biomarker is an integrated measure of cumulative exposures to relevant stressors across life, or whether it is marking additional risk pathways. Randomized trials to reduce the rate of decline in physical capability or delay incident disability could benefit from including middle-aged adults and adding NT-proBNP and IL-6 as intermediate outcomes.

NT-proBNP and Risk of Dementia in a General Japanese Elderly Population: The Hisayama Study

Background Epidemiological evidence implies a link between heart disease and dementia. However, few prospective studies have assessed the association between serum NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels and dementia. Methods and Results A total of 1635 community-dwelling Japanese elderly aged ≥60 years without dementia (57% women, mean age±SD 70.8±7.7 years) were followed up for 10 years. Serum NT-proBNP levels were divided into 4 categories (≤54, 55-124, 125-299, and ≥300 pg/mL). The hazard ratios were estimated using a Cox proportional hazards model. During the follow-up period, 377 subjects developed all-cause dementia, 247 Alzheimer disease, and 102 vascular dementia. The age- and sex-adjusted incidence of all-cause dementia was 31.5 per 1000 person-years and increased significantly with higher serum NT-proBNP levels, being 16.4, 32.0, 35.7, and 45.5, respectively (P for trend <0.01). Subjects with serum NT-proBNP levels of ≥300 pg/mL had a significantly higher risk of all-cause dementia (hazard ratio=2.46, 95% CI 1.63-3.71) than those with serum NT-proBNP levels of ≤54 pg/mL after adjusting for confounders. Similar risks were observed for Alzheimer disease and vascular dementia. Incorporation of the serum NT-proBNP level into a model with known risk factors for dementia significantly improved the predictive ability for incident dementia (c-statistics 0.780-0.787, P=0.02; net reclassification improvement 0.189, P=0.001; integrated discrimination improvement 0.011, P=0.003). Conclusions Higher serum NT-proBNP levels were significantly associated with an increased risk of dementia. Serum NT-proBNP could be a novel biomarker for predicting future risk of dementia in the general elderly population.

Cross-Sectional Associations Between Cardiac Biomarkers, Cognitive Performance, and Structural Brain Changes Are Modified by Age

Objective- NT-proBNP (N-terminal pro-B-type natriuretic peptide) and cardiac troponin T (cTNT) are associated with cognitive performance. Whether this extends to individuals <60 years of age is unclear. We investigated whether age modified the associations between NT-proBNP and cTNT and cognitive performance and structural brain changes. Approach and Results- In 3011 individuals (60±8 years; 49% women), NT-proBNP and cTNT, memory, information processing speed and executive functioning, grey matter (GM) and white matter, and white matter hyperintensity (WMH) volumes were determined. We used regression, adjusted for educational level, cardiovascular factors, and lifestyle factors, to test whether cross-sectional associations between biomarkers and cognitive performance and structural brain changes were modified by age (<60 versus ≥60 years). ≥60 years, higher NT-proBNP was associated with lower memory (β [SD] per 10-fold higher level [95% confidence interval (CI)], -0.11 [-0.22 to -0.00]), information processing speed (-0.12 [95% CI, -0.21 to -0.03]), executive functioning (-0.12 [95% CI, -0.22 to -0.03]), and smaller GM (β [mL] per 10-fold higher level, -6.89 [95% CI, -11.58 to -2.20]). Additionally, higher cTNT was associated with lower memory (-0.33 [95% CI, -0.53 to -0.12]) and information processing speed (-0.17 [95% CI, -0.3 to -0.01]); with smaller GM (-16.07 [95% CI, -24.90 to -7.24]) and greater WMH (10^β WMH per 10-fold higher level, 0.31 [95% CI, 0.10-0.52]). <60 years, NT-proBNP and cTNT were not associated with cognitive performance ( P_interaction, <0.10). In contrast, higher NT-proBNP was associated with smaller GM (-7.43 [95% CI, -11.70 to -3.16]) and greater WMH (0.13 [95% CI, 0.01-0.25]; P_interaction,>0.10). Higher cTNT was associated with greater WMH (0.18 [95% CI, -0.01 to 0.37]; P_interaction,>0.10) but not with GM (0.07 [95% CI, -6.87 to 7.02]; P_interaction, <0.10). Conclusions- Biomarkers of cardiac injury are continuously associated with structural brain changes in both older and younger individuals but with poorer cognitive performance only in older individuals. These findings stress the continuous nature of the heart-brain axis in the development of cognitive impairment.

Natriuretic Peptides in Post-mortem Brain Tissue and Cerebrospinal Fluid of Non-demented Humans and Alzheimer's Disease Patients

Animal studies suggest the involvement of natriuretic peptides (NP) in several brain functions that are known to be disturbed during Alzheimer's disease (AD). However, it remains unclear whether such findings extend to humans. In this study, we aimed to: (1) map the gene expression and localization of NP and their receptors (NPR) in human post-mortem brain tissue; (2) compare the relative amounts of NP and NPR between the brain tissue of AD patients and non-demented controls, and (3) compare the relative amounts of NP between the cerebrospinal fluid (CSF) of AD patients and non-demented controls. Using the publicly available Allen Human Brain Atlas dataset, we mapped the gene expression of NP and NPR in healthy humans. Using immunohistochemistry, we visualized the localization of NP and NPR in the frontal cortex of AD patients (n = 10, mean age 85.8 ± 6.2 years) and non-demented controls (mean age = 80.2 ± 9.1 years). Using Western blotting and ELISA, we quantified the relative amounts of NP and NPR in the brain tissue and CSF of these AD patients and non-demented controls. Our results showed that NP and NPR genes were ubiquitously expressed throughout the brain in healthy humans. NP and NPR were present in various cellular structures including in neurons, astrocyte-like structures, and cerebral vessels in both AD patients and non-demented controls. Furthermore, we found higher amounts of NPR type-A in the brain of AD patients (p = 0.045) and lower amounts of NP type-B in the CSF of AD patients (p = 0.029). In conclusion, this study shows the abundance of NP and NPR in the brain of humans suggesting involvement of NP in various brain functions. In addition, our findings suggest alterations of NP levels in the brain of AD patients. The role of NP in the development and progression of AD remains to be elucidated.

Effects of serum N-terminal pro B-type natriuretic peptide and D-dimer levels on patients with acute ischemic stroke

Objective:

To detect the serum levels of D-dimer and N-terminal pro B-type natriuretic peptide (NT-pro BNP) in patients with Acute Ischemic Stroke (AIS), and to explore the risk factors of AIS.

Methods:

A total of 246 AIS patients treated in our hospital from January 2015 to January 2017 were selected. Meanwhile, 240 healthy subjects were selected as a control group. The D-dimer and NT-pro BNP levels of the two groups were compared. Correlations of such levels with age, gender, blood lipid, Intima-Media Thickness (IMT), fibrinogen and degree of neurological deficits were analyzed.

Results:

The AIS group had significantly higher levels of Triglyceride (TG), Low-Density Lipoprotein (LDL), D-dimer, NT-pro BNP and fibrinogen as well as IMT than those of the control group, but the High-Density Lipoprotein (HDL) level of the AIS group was significantly lower (P<0.05). The patients with different genders and ages had significantly different D-dimer and NT-pro BNP levels (P<0.05). The D-dimer and NT-pro BNP levels were correlated with gender and age. Such levels of females were significantly higher than those of males (P<0.05). The D-dimer and NT-pro BNP levels of the ≥60 years old group significantly exceeded those of the <60 years old group (P<0.05). The levels of D-dimer and NT-pro BNP were negatively correlated with that of HDL (P<0.05), but positively correlated with TG, LDL and fibrinogen levels, IMT, and National Institutes of Health Stroke Scale score (P<0.05). Multivariate Logistic regression analysis showed that the OR values of D-dimer and NT-pro BNP were 3.65 and 6.96 respectively.

Conclusion:

Serum D-dimer and NT-pro BNP levels usually increased in AIS patients, and the levels were significantly correlated with AIS onset.

N-Terminal pro-Brain Natriuretic Peptide and Associations With Brain Magnetic Resonance Imaging (MRI) Features in Middle Age: The CARDIA Brain MRI Study

Objective

As part of research on the heart–brain axis, we investigated the association of N-terminal pro-brain natriuretic peptide (NT-proBNP) with brain structure and function in a community-based cohort of middle-aged adults from the Brain Magnetic Resonance Imaging sub-study of the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

Approach and results

In a cohort of 634 community-dwelling adults with a mean (range) age of 50.4 (46–52) years, we examined the cross-sectional association of NT-proBNP to total, gray (GM) and white matter (WM) volumes, abnormal WM load and WM integrity, and to cognitive function tests [the Digit Symbol Substitution Test (DSST), the Stroop test, and the Rey Auditory–Verbal Learning Test]. These associations were examined using linear regression models adjusted for demographic and cardiovascular risk factors and cardiac output. Higher NT-proBNP concentration was significantly associated with smaller GM volume (β = −3.44; 95% CI = −5.32, −0.53; p = 0.003), even after additionally adjusting for cardiac output (β = −2.93; 95% CI = −5.32, −0.53; p = 0.017). Higher NT-proBNP levels were also associated with lower DSST scores. NT-proBNP was not related to WM volume, WM integrity, or abnormal WM load.

Conclusion

In this middle-aged cohort, subclinical levels of NT-proBNP were related to brain function and specifically to GM and not WM measures, extending similar findings in older cohorts. Further research is warranted into biomarkers of cardiac dysfunction as a target for early markers of a brain at risk.

N-Terminal Pro-B-Type Natriuretic Peptide and Risk of Future Cognitive Impairment in the REGARDS Cohort

BACKGROUND

Improved understanding of the etiology of cognitive impairment is needed to develop effective preventive interventions. Higher amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is a biomarker of cardiac dysfunction associated with risk of cardiovascular diseases and stroke in apparently healthy people.

OBJECTIVE

To study the association of NT-proBNP with risk of incident cognitive impairment.

METHODS

The Reasons for Geographic and Racial Differences in Stroke is a national cohort study of 30,239 black and white Americans age 45 and older at baseline, enrolled in 2003-7. Among participants without prebaseline stroke or cognitive impairment, baseline NT-proBNP was measured in 470 cases of incident cognitive impairment and 557 controls. Cases were participants scoring below the 6th percentile of demographically-adjusted means on at least 2 of 3 serially administered tests (word list learning, word list recall and semantic fluency) over 3.5 years follow-up.

RESULTS

Adjusting for age, gender, race, region of residence, education, and income, there was an increased odds ratio of incident cognitive impairment with increasing NT-proBNP; participants in the 4th versus 1st quartile (>127 versus ≤33 pg/ml) had a 1.69-fold increased odds (95% CI 1.11-2.58). Adjustment for cardiovascular risk factors and presence of an apolipoprotein E4 allele had no substantial impact on the odds ratio. Results did not differ by age, race, gender, or presence of an apolipoprotein E4 allele.

CONCLUSION

Higher NT-pro-BNP was associated with incident cognitive impairment in this prospective study, independent of atherogenic and Alzheimer's disease risk factors. Future work should clarify pathophysiologic connections of NT-proBNP and cognitive dysfunction.

Subclinical Atherosclerosis, Cardiac and Kidney Function, Heart Failure, and Dementia in the Very Elderly

BACKGROUND

Heart failure (HF) and dementia are major causes of disability and death among older individuals. Risk factors and biomarkers of HF may be determinants of dementia in the elderly. We evaluated the relationship between biomarkers of cardiovascular disease and HF and risk of dementia and death. Three hypotheses were tested: (1) higher levels of high-sensitivity cardiac troponin T, N-terminal of prohormone brain natriuretic peptide, and cystatin C predict risk of death, cardiovascular disease, HF, and dementia; (2) higher levels of cardiovascular disease biomarkers are associated with increased risk of HF and then secondary increased risk of dementia; and (3) risk of dementia is lower among participants with a combination of lower coronary artery calcium, atherosclerosis, and lower high-sensitivity cardiac troponin T (myocardial injury).

METHODS AND RESULTS

The Cardiovascular Health Study Cognition Study was a continuation of the Cardiovascular Health Study limited to the Pittsburgh, PA, center from 1998-1999 to 2014. In 1992-1994, 924 participants underwent magnetic resonance imaging of the brain. There were 199 deaths and 116 developed dementia before 1998-1999. Of the 609 participants eligible for the Pittsburgh Cardiovascular Health Study Cognition Study, 87.5% (n=532) were included in the study. There were 120 incident HF cases and 72% had dementia. In 80 of 87, dementia preceded HF. A combination of low coronary artery calcium score and low high-sensitivity cardiac troponin T was significantly associated with reduced risk of dementia and HF.

CONCLUSIONS

Most participants with HF had dementia but with onset before HF. Lower high-sensitivity cardiac troponin T and coronary artery calcium was associated with low risk of dementia based on a small number of events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005133.

N-Terminal Pro-B-Type Natriuretic Peptide and Subclinical Brain Damage in the General Population

Purpose To investigate the association between N-terminal pro-B-type natriuretic peptide (NT-proBNP), which is a marker of heart disease, and markers of subclinical brain damage on magnetic resonance (MR) images in community-dwelling middle-aged and elderly subjects without dementia and without a clinical diagnosis of heart disease. Materials and Methods This prospective population-based cohort study was approved by a medical ethics committee overseen by the national government, and all participants gave written informed consent. Serum levels of NT-proBNP were measured in 2397 participants without dementia or stroke (mean age, 56.6 years; age range, 45.7-87.3 years) and without clinical diagnosis of heart disease who were drawn from the population-based Rotterdam Study. All participants were examined with a 1.5-T MR imager. Multivariable linear and logistic regression analyses were used to investigate the association between NT-proBNP level and MR imaging markers of subclinical brain damage, including volumetric, focal, and microstructural markers. Results A higher NT-proBNP level was associated with smaller total brain volume (mean difference in z score per standard deviation increase in NT-proBNP level, -0.021; 95% confidence interval [CI]: -0.034, -0.007; P = .003) and was predominantly driven by gray matter volume (mean difference in z score per standard deviation increase in NT-proBNP level, -0.037; 95% CI: -0.057, -0.017; P < .001). Higher NT-proBNP level was associated with larger white matter lesion volume (mean difference in z score per standard deviation increase in NT-proBNP level, 0.090; 95% CI: 0.051, 0.129; P < .001), with lower fractional anisotropy (mean difference in z score per standard deviation increase in NT-proBNP level, -0.048; 95% CI: -0.088, -0.008; P = .019) and higher mean diffusivity (mean difference in z score per standard deviation increase in NT-proBNP level, 0.054; 95% CI: 0.018, 0.091; P = .004) of normal-appearing white matter. Conclusion In community-dwelling persons, higher serum NT-proBNP levels are associated with volumetric and microstructural MR imaging markers of subclinical brain damage. ^© RSNA, 2016 Online supplemental material is available for this article.

Hemodynamic and serum cardiac markers and risk of cognitive impairment and dementia

INTRODUCTION

Cardiac function is a key player in maintaining energy homeostasis in the brain. Heart failure is closely related to higher risk of neurocognitive disorders. Recent evidence shows that this relationship might not be limited to patients with advanced heart failure, and even suboptimal cardiac functioning is associated with accelerated brain aging. Hence, hemodynamic and serum cardiac markers may provide valuable information about the risk of dementia.

METHODS

We provide an overview on the link between cardiac markers and cognitive function by a systematic search in five databases. Furthermore, we discuss the pathophysiological aspects of this link and highlight the pertinent clinical and public health implications.

RESULTS

Increasing evidence supports the associations of hemodynamic and serum cardiac markers with accelerated cognitive decline.

DISCUSSION

Hemodynamic and serum cardiac markers are closely linked with risk of cognitive impairment. This highlights the significance of the heart-brain connection in reducing the burden of dementia.

Natriuretic peptides in the central nervous system: Novel targets for cognitive impairment

Natriuretic peptides (NPs) are traditionally known as cardiac hormones with diuretic, natriuretic and blood pressure lowering properties. Evidence indicates that NPs and their receptors are abundant in the central nervous system, suggesting their involvement in regulation of various brain functions. It has been shown that NPs are involved in the regulation of neurovascular and blood-brain barrier integrity, neuro-inflammation, neuroprotection, synaptic transmission and brain fluid homeostasis. In addition, NPs might contribute to the brain's inhibitory control over the hypothalamic-pituitary-adrenal axis. Studies have also shown that high systemic levels of NPs are associated with cognitive impairment independent of cardiovascular risk factors. In this review we discuss the potential roles of NPs in regulating structural and functional integrity of the brain. Based on the available neurobiological and clinical evidence, we propose that NPs might represent as potential novel diagnostic and therapeutic targets for cognitive impairment.