Influence of confounding factors on plasma Mid-Regional pro-Adrenomedullin and Mid-Regional pro-A-type Natriuretic Peptide concentrations in healthy individuals

Associations of Plasma Bioactive Adrenomedullin Levels with Cardiovascular Risk Factors in BRCA1/2 Mutation Carriers

Background Cardiovascular disease (CVD) is an important cause of morbidity and mortality in breast cancer survivors. Effective screening modalities to identify CVD risk are lacking in this population. Adrenomedullin (ADM) has been suggested as a biomarker for subclinical cardiac dysfunction in the general population. Levels of ADM have been proven to be responsive to lifestyle changes that lead to improved cardiovascular health. As BRCA1/2 mutation carriers are deemed to be at an increased risk for CVD, the aim of this study was to examine plasma ADM levels in a cohort of BRCA mutation carriers and to assess their association with cardiovascular risk factors.

Methods Plasma ADM concentrations were measured in 292 female BRCA1/2 mutation carriers with and without a history of breast cancer. Subjects were classified into high versus low ADM levels based on the median ADM level in the entire cohort (13.8 pg/mL). Logistic regression models were used to estimate the odds ratios (OR) of having elevated ADM levels by several cardiovascular risk factors.

Results Of all women (median age: 43 years), 57.5% had a previous diagnosis of breast cancer. The median time between diagnosis and study entry was three years (range: 0 – 32 years). Women presenting with metabolic syndrome had 22-fold increased odds of having elevated ADM levels (p < 0.001). Elevated ADM levels were associated with lower cardiorespiratory fitness (OR = 0.88, p < 0.001) and several parameters of obesity (p < 0.001). ADM levels were higher in women who have ever smoked (OR = 1.72, p = 0.02). ADM levels were not associated with a previous diagnosis of breast cancer (p = 0.28).

Conclusions This is the first study in BRCA mutation carriers that has linked circulating ADM levels to traditional cardiovascular risk factors. The long-term clinical implications of these findings are yet to be determined.

Impact of adrenomedullin levels on clinical risk stratification and outcome in subarachnoid haemorrhage

PURPOSE

To use classification tree analysis to identify risk factors for nonsurvival in a neurological patients with subarachnoid haemorrhage (SAH) and to propose a clinical model for predicting of mortality.

METHODS

Prospective study of SAH admitted to a Critical Care Department and Stroke Unit over a 2-year period. Middle region of pro-ADM plasma levels (MR-proADM) was measured in EDTA plasma within the first 24 hours of hospital admission using the automatic immunofluorescence test. A regression tree was made to identify prognostic models for the development of mortality at 90 days.

RESULTS

Ninety patients were included. The mean MR-proADM plasma value in the samples analysed was 0.78 ± 0.41 nmol/L. MR-proADM plasma levels were significantly associated with mortality at 90 days (1.05 ± 0.51 nmol/L vs 0.64 ± 0.25 nmol/L; P < .001). Regression tree analysis provided an algorithm based on the combined use of clinical variables and one biomarker allowing accurate mortality discrimination of three distinct subgroups with high risk of 90-day mortality ranged from 75% to 100% (AUC 0.9; 95% CI 0.83-0.98).

CONCLUSIONS

The study established a model (APACHE II, MR-proADM and Hunt&Hess) to predict fatal outcomes in patients with SAH. The proposed decision-making algorithm may help identify patients with a high risk of mortality.

The prognostic blood biomarker proadrenomedullin for outcome prediction in patients with chronic obstructive pulmonary disease (COPD): a qualitative clinical review

Plasma proadrenomedullin (ProADM) is a blood biomarker that may aid in multidimensional risk assessment of patients with chronic obstructive pulmonary disease (COPD). Co-secreted 1:1 with adrenomedullin (ADM), ProADM is a less biologically active, more chemically stable surrogate for this pluripotent regulatory peptide, which due to biological and ex vivo physical characteristics is difficult to reliably directly quantify. Upregulated by hypoxia, inflammatory cytokines, bacterial products, and shear stress and expressed widely in pulmonary cells and ubiquitously throughout the body, ADM exerts or mediates vasodilatory, natriuretic, diuretic, antioxidative, anti-inflammatory, antimicrobial, and metabolic effects. Observational data from four separate studies totaling 1366 patients suggest that as a single factor, ProADM is a significant independent, and accurate, long-term all-cause mortality predictor in COPD. This body of work also suggests that combined with different groups of demographic/clinical variables, ProADM provides significant incremental long-term mortality prediction power relative to the groups of variables alone. Additionally, the literature contains indications that ProADM may be a global cardiopulmonary stress marker, potentially supplying prognostic information when cardiopulmonary exercise testing results such as 6-min walk distance are unavailable due to time or other resource constraints or to a patient's advanced disease. Prospective, randomized, controlled interventional studies are needed to demonstrate whether ProADM use in risk-based guidance of site-of-care, monitoring, and treatment decisions improves clinical, quality-of-life, or pharmacoeconomic outcomes in patients with COPD.

ICG-liver test versus new biomarkers as prognostic markers for prolonged length of stay in critically ill patients - a prospective study of accuracy for prediction of length of stay in the ICU

Background

Prognostic abilities of medical parameters, which are scoring systems, measurements and biomarkers, are important for stratifying critically ill patients. Indocyanine green plasma disappearance (ICG-PDR) is an established clinical tool for the assessment of liver perfusion and function. Copeptin, MR-proANP and pro-ADM are biomarkers whose prognostic value is still unclear. The goal of this prospective study was to evaluate ICG-PDR, copeptin, MR-proANP and pro-ADM to predict prolonged length of stay (pLOS) in the ICU.

Methods

This study was conducted as a prospective single center study including 110 consecutively admitted ICU patients. Primary endpoint was prolonged length of stay (pLOS) in the ICU, defined as more than three days of stay there.

Results

ROC analysis showed an AUC of 0.73 for ICG-PDR, 0.70 for SAPS II, 0.65 for MR-proANP, 0.64 for pro-ADM and 0.54 for copeptin for pLOS in the ICU.

Conclusions

The prediction of pLOS in the ICU might be better by means of ICG-PDR than with the new biomarkers copeptin, MR-proANP or pro-ADM. Nevertheless, there is more need for research to evaluate whether ICG-PDR is an overall prognostic marker for pLOS.

Trial registration

(ClinicalTrials.gov number, NCT01126554).

Midregional pro-atrial natriuretic peptide in the general population/Insights from the Gutenberg Health Study

BACKGROUND

The use of biomarkers is firmly established for the assessment of cardiovascular disease. Emerging biomarkers such as midregional pro-atrial natriuretic peptide (MR-proANP) challenge established markers regarding risk prediction and stratification ability. The aim of the present study was to describe the distribution of a contemporary MR-proANP assay in a large population-representative sample and to evaluate the association with prevalent cardiac diseases and cardiovascular risk factors.

METHODS

MR-proANP was determined by the use of a contemporary commercially available assay (BRAHMS GmbH, Hennigsdorf, Germany) in a representative sample of 5000 participants from the large population-based Gutenberg Health Study. N-terminal pro B-type natriuretic peptide (NT-proBNP) was used as a comparator.

RESULTS

Mean age was 55.5 ± 10.9 years. Coronary artery disease (CAD) was documented in 4.6%, heart failure (HF) in 1.5% of the study participants. We observed a moderate to strong correlation of the biomarkers with age, diabetes, hypertension, smoking, renal function, prevalence of CAD and HF. Males showed lower MR-proANP concentrations than females. MR-proANP showed no relevant correlation with BMI (ρ=-0.030) and CRP (ρ=0.039). Reference limits for MR-proANP representing the 95th/97.5th/99th percentile were determined for healthy individuals with 116/132/169 pmol/mL.

CONCLUSIONS

The current analysis in a large population-based sample elucidates the correlations and distribution of MR-proANP. Its concentration in healthy individuals depends on prevalent cardiovascular diseases and classical risk factors. The reported population-based reference values might be useful for distinguishing between healthy and diseased individuals, thus improving risk stratification and triaging in various clinical settings.

Midregional proadrenomedullin and its change predicts recurrent major coronary events and heart failure in stable coronary heart disease patients: the LIPID study

BACKGROUND

Biomarkers may contribute to risk stratification in coronary heart disease (CHD). We examined whether plasma midregional proadrenomedullin (MR-proADM) concentration at baseline and its change over one year predicts long-term outcomes in stable CHD patients.

METHODS

The LIPID study randomised patients 3-36 months after an acute coronary syndrome with total cholesterol 4.0-7.0 mmol/L (155-271 mg/dL), to placebo or pravastatin 40 mg. Follow-up was 6.0 years. MR-proADM plasma concentrations at baseline and one year later were determined in 7863 and 6658 patients, respectively. These were categorised into quartiles to perform Cox regression analysis, adjusting for baseline parameters.

RESULTS

Baseline MR-proADM concentrations predicted major CHD events (non-fatal myocardial infarction or CHD death; hazard ratio (HR) 1.52, 1.26-1.84 for Q4-Q1), CHD death (HR 2.21, 1.67-2.92), heart failure (HR 2.30, 1.78-2.97) and all-cause mortality (HR 1.82, 1.49-2.23). Associations were still significant after adjustment for baseline B-type natriuretic peptide (BNP) concentration. Increase in MR-proADM after one year was associated with increased risk of subsequent CHD events (HR 1.34, 1.08-1.66), non-fatal myocardial infarction (HR 1.50, 1.12-2.03), heart failure (HR 1.78, 1.37-2.30) and all-cause mortality (HR 1.31, 1.04-1.64). Associations with heart failure and all-cause mortality remained significant after adjusting for baseline and change in BNP concentration. Change in MR-proADM moderately improved risk reclassification for major CHD events (net reclassification improvement (NRI) 3.48%) but strongly improved risk reclassification for heart failure (NRI 5.60%).

CONCLUSIONS

Baseline and change in MR-proADM concentrations over one year are associated with risk of major clinical events, even after adjustment for BNP concentrations.

A single nucleotide polymorphism of interleukin-6 gene is related to plasma adrenomedullin levels

OBJECTIVE

Elevated plasma adrenomedullin (ADM) levels are associated with cardiovascular diseases. Single nucleotide polymorphisms (SNPs) in the gene encoding ADM (ADM) are associated with plasma ADM levels. The presence of a nuclear factor for interleukin-6 (IL-6) expression binding site in the promoter region of the ADM gene suggests a possible relationship between the expression of the ADM and IL-6. Therefore, we investigated whether plasma ADM levels are related to SNPs in the gene encoding IL-6 (IL6).

METHODS

Plasma ADM levels were measured in 476 subjects in the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS2). The subjects were genotyped for three tagging SNPs in the IL6 gene.

RESULTS

The minor allele frequencies of the IL6 SNPs rs17147230, rs1800796 and rs2069837 were 41·8%, 20·0% and 15·4%, respectively. The tagging SNP, rs17147230, was associated with plasma ADM levels after adjusting for age and sex (β=-0·096, P = 0·034). The association was significant in women (β=-0·115, P = 0·021) but not in men. Among all subjects, plasma ADM levels decreased with an increasing number of minor alleles of rs17147230 in multivariate analysis (P = 0·034). Compared to subjects with the AA genotype, subjects with the TT genotype had plasma ADM levels 12·8% lower (95% CI: 0·6-23·5%, P = 0·041). Haplotype analysis demonstrated a significant association of the haplotype ACA with plasma ADM levels in women (P < 0·05).

CONCLUSION

Plasma ADM levels are related to the SNP rs17147230 in IL6 gene. The effect of the polymorphism on inflammation and cardiovascular disease remains to be determined.

Body mass index in chronic heart failure: association with biomarkers of neurohormonal activation, inflammation and endothelial dysfunction

BACKGROUND

Low body mass index (BMI) is associated with a poor outcome in chronic heart failure (CHF). An inverse association between BMI and adiponectin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been reported. The aim of the present study was to investigate whether novel markers of neurohormonal activation, inflammation, and endothelial dysfunction are associated with BMI in CHF.

METHODS

In a cross-sectional study including 171 patients with CHF and a left ventricular ejection fraction (LVEF) ≤45% the impact of BMI on circulating plasma concentrations of adiponectin, α-defensins, high sensitivity C-reactive protein (hsCRP), copeptin, mid-regional pro-adrenomedullin (MR-proADM), NT-proBNP, and mid-regional pro-A-type natriuretic peptide (MR-proANP) were evaluated.

RESULTS

In multivariable linear regression analysis including age, sex, LVEF, New York Heart Association functional classification (NYHA), estimated glomerular filtration rate (eGFR), and diabetes, only NT-proBNP (β = -0.32) and adiponectin (β = -0.39) remained independently associated with BMI. MR-proANP was associated with BMI but adjusting for age attenuated the relation being no longer significant.

CONCLUSIONS

Among biomarkers typically increased in patients with CHF only adiponectin and NT-proBNP demonstrated independent inverse associations with BMI. This indicates a direct effect of these two biomarkers enhancing the wasting process seen in CHF.

Association of MR-proadrenomedullin with cardiovascular risk factors and subclinical cardiovascular disease

AIMS AND BACKGROUND

Midregional proadrenomedullin (MR-proADM) is a protein, which exerts various effects on the cardiovascular system. Recent studies underscored its prognostic implications in patients with acute dyspnea and cardiovascular diseases. Therefore, we aimed to determine the distribution of MR-proADM in the general population and to reveal potential associations of MR-proADM with cardiovascular risk factors and measures of subclinical cardiovascular disease.

METHODS AND RESULTS

MR-proADM plasma concentrations were determined in individuals of the population-based cohort of the Gutenberg Health Study (N = 5000) using a commercially available fluoroimmunoassay. Individuals were enrolled between April 2007 and October 2008. Subclinical cardiovascular disease was assessed using echocardiographic and functional measures of myocardial and vascular function. The mean age of the study population was 55.5 ± 10.9 years. In the overall population we determined a median MR-proADM plasma concentration of 0.44 nmol/L in men and women. MR-proADM concentrations were elevated in individuals with hypertension, diabetes, dyslipidemia, known cardiovascular disease, heart failure, peripheral artery disease, atrial fibrillation, and history of myocardial infarction and stroke. In men, we observed a positive association of MR-proADM with reduced ejection fraction, intraventricular septal diameter, wall thickness, and echocardiographic measures of diastolic dysfunction.

CONCLUSIONS

In this study, we present age-dependent reference values for MR-proADM in a representative population sample. Elevated MR-proADM plasma concentrations were strongly associated with classical cardiovascular risk factors and manifest cardiovascular diseases. Furthermore, we revealed a gender-specific association with echocardiographic measures of hypertension. MR-proADM seems to be a promising prognostic biomarker for subclinical and manifest cardiovascular disease.

The prognostic capacity of B-type natriuretic peptide on cognitive disorder varies by age

INTRODUCTION

It is known that blood levels of natriuretic peptides associate with cognitive disorder among the middle-aged. We aimed to test whether this association is valid in an older population aged 75 years or older.

METHODS

A total of 601 older subjects aged 75 or older participated in the study. A subgroup of 137 with a diagnosed cognitive disorder were tested for natriuretic peptides (ANP, NT-proANP, and BNP), and compared with age-matched controls (n = 464). The control group was followed-up for 5 years, and the association of the baseline BNP with the occurrence of cognitive impairment was studied.

RESULTS

In the youngest age tertile (75-78 y), BNP was significantly associated with a diagnosed cognitive disorder when other factors with a known effect on natriuretic peptides were taken into account. In the oldest tertile (83-96 y), higher BNP values suggested the absence of cognitive dysfunction. ANP and NT-proANP did not associate with the presence of cognitive impairment. Among the control group, BNP predicted a cognitive disorder at follow-up, but only in the youngest tertile.

CONCLUSIONS

The previously found link between a high BNP concentration and cognitive disorder in older people is only valid among those aged less than 79 years.

Influence of age, race, sex, and body mass index on interpretation of midregional pro atrial natriuretic peptide for the diagnosis of acute heart failure: results from the BACH multinational study

AIMS

Midregional pro atrial natriuretic peptide (MR-proANP) is useful for diagnosing acute heart failure (HF) in patients presenting to the Emergency Department with dyspnoea. Optimal interpretation of MR-proANP requires understanding of how various demographic variables influence its levels and performance as a diagnostic marker. We sought to determine how age, race, sex, and body mass index (BMI) affect the levels and interpretation of MR-proANP for the diagnosis of acute HF.

METHODS AND RESULTS

The Biomarkers in Acute Heart Failure (BACH) study was an international 15-centre study of 1641 patients presenting to the Emergency Department with acute dyspnoea. Of these, 1352 had complete information on age, race, sex, and BMI. MR-proANP levels increased with age and were higher in men and in patients with lower BMI. MR-proANP performed better as a diagnostic marker in younger individuals and in blacks compared with whites. Despite this, MR-proANP at the recommended cut-off point of 120 pmol/L was >90 % sensitive in ruling out the diagnosis of acute HF in all subgroups of patients except white subjects <50 years old.

CONCLUSION

Age, race, sex, and BMI affect MR-proANP levels to various degrees. However, the diagnostic performance of the recommended cut-off point of 120 pmol/L to rule out acute HF was robust across most subgroups. Although both sex and BMI affected MR-proANP levels, they did not alter its overall diagnostic performance. Lower cut-off points for MR-proANP could be considered in younger patients and in patients with a higher BMI, to optimize diagnostic sensitivity.