Copeptin Kinetics in Acute Ischemic Stroke May Differ According to Revascularization Strategies: Pilot Data

Background and Purpose- Prognostic value of copeptin in acute ischemic stroke has been widely reported. This study aimed to evaluate copeptin temporal profile according to revascularization strategies and the development of brain edema and hemorrhagic transformation. Methods- Plasma copeptin and brain edema and hemorrhagic transformation assessed by computed tomography/magnetic resonance imaging were evaluated upon admission (T0), at 24 hours (T1), and between the third and fifth day of hospitalization (T2) in 34 acute ischemic stroke patients. Results- Median copeptin concentration was 50.71 pmol/L at T0, 18.31 pmol/L at T1, and 10.92 pmol/L at T2. Copeptin at T1 was higher in patients with medium/severe brain edema at T2 (32.25 versus 13.67 pmol/L; P=0.038) and hemorrhagic transformation at T1 (93.10 versus 13.67 pmol/L; P<0.003) and T2 (85.70 versus 14.45 pmol/L; P=0.024). Copeptin level drop (CopΔ_T1-T0) was significantly steeper in patients receiving revascularization, particularly in those undergoing combined therapy (-129.34 versus -5.43 pmol/L; P=0.038). Δ_T1-T0 also correlated with Thrombolysis in Cerebral Infarction score (P<0.001). Conclusions- Copeptin resulted associated with brain edema and hemorrhagic transformation in acute ischemic stroke, and its drop at 24 hours may mirror effective brain vessel recanalization.

Vasopressin inactivation: Role of insulin-regulated aminopeptidase

The physiological importance of vasopressin inactivation has long been appreciated, but the mechanisms and potential pathophysiologic roles of this process remain active subjects of research. Human Placental Leucine Aminopeptidase (P-LAP, encoded by the LNPEP gene) is an important determinant of vasopressinase activity during pregnancy and is associated with gestational diabetes insipidus and preeclampsia. Insulin-Regulated Aminopeptidase (IRAP), the rodent homologue of P-LAP, is coregulated with the insulin-responsive glucose transporter, GLUT4, in adipose and muscle cells. Recently, the Tether containing a UBX domain for GLUT4 (TUG) protein was shown to mediate the coordinated regulation of water and glucose homeostasis. TUG sequesters IRAP and GLUT4 intracellularly in the absence of insulin. Insulin and other stimuli cause the proteolytic cleavage of TUG to mobilize these proteins to the cell surface, where IRAP acts to terminate the activity of circulating vasopressin. Intriguingly, genetic variation in LNPEP is associated with the vasopressin response and mortality during sepsis, and increased copeptin, a marker of vasopressin secretion, is associated with cardiovascular and metabolic disease. We propose that in the setting of insulin resistance in muscle, increased cell-surface IRAP and accelerated vasopressin degradation cause a compensatory increase in vasopressin secretion. The increased vasopressin concentrations present at the kidneys then contribute to hypertension in the metabolic syndrome. Further analyses of metabolism and of vasopressin and copeptin may yield novel insights into a unified pathophysiologic mechanism linking insulin resistance and hypertension, and potentially other components of the metabolic syndrome, in humans.

Vasopressin and Copeptin in health and disease

Arginine Vasopressin (AVP) and copeptin derive from the same precursor molecule. Due to the equimolar secretion, copeptin responds as rapidly as AVP to osmotic, hemodynamic and unspecific stress-related stimuli and both peptides show a very strong correlation. The physiological functions of AVP are homeostasis of fluid balance, vascular tonus and regulation of the endocrine stress response. In contrast, the exact function of copeptin remains unknown. Since copeptin, in contrast to AVP, can easily be measured with a sandwich immunoassay, its main function so far that it indirectly indicates the amount of AVP in the circulation. Copeptin has emerged as a useful measure in different diseases. On one hand, through its characteristics as a marker of stress, it provides a unique measure of the individual stress burden. As such, it is a prognostic marker in different acute diseases such as ischemic stroke or myocardial infarction. On the other side, it has emerged as a promising marker in the diagnosis of AVP-dependent fluid disorders. Copeptin reliably differentiates various entities of the polyuria polydipsia syndrome; baseline levels >20 pmol/L without prior fluid deprivation identify patients with nephrogenic diabetes insipidus, whereas levels measured upon osmotic stimulation with hypertonic saline or upon non-osmotic stimulation with arginine differentiate primary polydipsia from central diabetes insipidus. In patients with hyponatremia, low levels of copeptin together with low urine osmolality identify patients with primary polydipsia, but copeptin levels overlap in all other causes of hyponatremia, limiting its diagnostic use in hyponatremia. Copeptin has also been put forward as predictive marker for autosomal dominant polycystic kidney disease and for diabetes mellitus, but more studies are needed to confirm these findings.

The association between serum adiponectin and 3-month outcome after ischemic stroke

BACKGROUND

Although adiponectin is a major adipocytokine that affects the pathogenesis of various cardiovascular diseases, its clinical significance in stroke remains controversial. The purpose of this study was to assess the impact of serum adiponectin levels on functional prognosis in patients with ischemic stroke.

METHODS

This was a prospective, observational cohort study. Consecutive first-ever ischemic stroke patients without any pre-morbid handicap admitted to our hospital were identified from December 2017 to December 2018. Serum concentration of adiponectin was routinely measured within the first 24 h after admission by a commercially available sandwich ELISA. Associations between adiponectin and either clinical severity at admission, poor outcomes or mortality at 3-month after admission were analyzed using logistic regression to obtain odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The serum level of adiponectin was obtained in 227 patients with a median value of 7.0 μg/ml, which was significantly higher (P < 0.001) than in those heathy control. Adiponectin levels were associated with moderate-to-high stroke, and risk increased by 12% (OR = 1.12; 95% CI 1.03-1.25; P = 0.002). Patients with a poor outcome and nonsurvivors had significantly increased adiponectin levels on admission (P < 0.001, all). In multivariate logistic regression analysis, adiponectin was an independent predictor of functional outcome and mortality, and risk increased by 24% (OR = 1.24, 95% CI 1.13-1.37; P < 0.001) and 31% (1.31 [1.18-1.46], P < 0.001), respectively. Kaplan-Meier analysis suggested that the patients with high serum adiponectin levels had a higher risk of death than those patients with low levels (log-rank test P < 0.001).

CONCLUSIONS

Our results show that high adiponectin is associated with stroke severity and support the hypothesis that adiponectin can be serve as a biomarker of poor outcome after stroke, independent of baseline variables. Trial registration ChiCTR-OPC-17013501. Retrospectively Registered 21 September 2017.

Value of copeptin and the S-100b protein assay in ruling out the diagnosis of stroke-induced dizziness pattern in emergency departments

Background

Dizziness is a frequent reason for visiting emergency departments (EDs). Differentiating stroke from other causes is challenging for physicians. The role of biomarkers has been poorly assessed. We evaluated whether copeptin and S100b protein (PS100b) assessment, alone or in combination, could rule out stroke in patients visiting EDs for dizziness.

Methods

We included patients 18 years of age or older, visiting the adult ED of a French university hospital for a new episode of dizziness evolving for less than 72 h. All patients underwent standardized physical examination (HINT [Head Impulse test, Nystagmus, test of skew deviation] maneuvers), copeptin and S-100b protein (PS100) measurement and injected brain imaging. Stroke diagnosis involved diffusion-weighted magnetic resonance imaging or, if not available, neurological examination and contrast brain CT scan compatible with the diagnosis.

Results

Of the 135 patients participating in the study, 13 (10%) had stroke. The sensitivity, specificity and positive and negative predictive values of copeptin/PS100 combination were 100% (95%CI, 77–100%), 48% (40–57%), 14% (11–27%) and 100% (94–100%), respectively. Values for copeptin alone were 77% (CI95% 0.50–0.91), 50% (CI95% 0.49–0.58), 14% (CI95% 0.08–0.24), 93% (CI95% 0.87–0.98), and for PS100 alone were 54% (CI95% 0.29–0.77), 97% (CI95% 0.92–0.99), 64% (CI95% 0.35–0.84), 95% (CI95% 0.90–0.98).

Conclusions

Absence of copeptin and PS100 elevation seems to ruling out the diagnosis of stroke in patients visiting the ED for a new episode of dizziness. These results need to be confirmed in a large-scale study.

Association of Serum Copeptin Levels with Patency of Infarct-Related Arteries in Patients with ST-Segment Elevation Myocardial Infarction

Background

Copeptin is widely used as a predictor of an adverse prognosis in many clinical conditions. Reduced antegrade coronary flow in an infarct-related artery (IRA) is associated with adverse clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to investigate whether copeptin level on admission was associated with IRA patency in STEMI patients.

Methods

A total of 88 patients were enrolled into the study and divided into two groups according to TIMI flow grade in the IRA before primary percutaneous coronary intervention.

Results

White blood cell count (p = 0.015), neutrophils (p = 0.047), N-terminal pro-brain natriuretic peptide (NTproBNP) (p < 0.001), copeptin (p < 0.001) and peak troponin I (p = 0.001) were significantly higher in the occluded IRA group with a significantly lower serum sodium level (p < 0.001). Age- and gender-adjusted multivariate analysis revealed that copeptin (OR = 1.970; p = 0.001), peak troponin I (1.055; p = 0.005) and NTproBNP (OR = 1.003; p = 0.010) were independent predictors of an occluded IRA. A copeptin cut-off value of > 6.8 ng/mL was found to predict an occluded IRA with a sensitivity of 80% and specificity of 100% (area under the curve: 0.917; p < 0.001). Performance ranking of the biomarkers that could predict an occluded IRA showed copeptin > peak troponin I = NTproBNP.

Conclusions

Copeptin levels were higher in the patients with an occluded IRA and STEMI. Higher levels of copeptin predicted an occluded IRA in the patients with STEMI who were admitted to the emergency department during the first three hours of chest pain.

Copeptin and its role in the diagnosis of diabetes insipidus and the syndrome of inappropriate antidiuresis

Copeptin is secreted in an equimolar amount to arginine vasopressin (AVP) but can easily be measured in plasma or serum with a sandwich immunoassay. The main stimuli for copeptin are similar to AVP, that is an increase in osmolality and a decrease in arterial blood volume and pressure. A high correlation between copeptin and AVP has been shown. Accordingly, copeptin mirrors the amount of AVP in the circulation. Copeptin has, therefore, been evaluated as diagnostic biomarker in vasopressin-dependent disorders of body fluid homeostasis. Disorders of body fluid homeostasis are common and can be divided into hyper- and hypoosmolar circumstances: the classical hyperosmolar disorder is diabetes insipidus, while the most common hypoosmolar disorder is the syndrome of inappropriate antidiuresis (SIAD). Copeptin measurement has led to a "revival" of the direct test in the differential diagnosis of diabetes insipidus. Baseline copeptin levels, without prior thirsting, unequivocally identify patients with nephrogenic diabetes insipidus. In contrast, for the difficult differentiation between central diabetes insipidus and primary polydipsia, a stimulated copeptin level of 4.9 pmol/L upon hypertonic saline infusion differentiates these two entities with a high diagnostic accuracy and is clearly superior to the classical water deprivation test. On the contrary, in the SIAD, copeptin measurement is of only little diagnostic value. Copeptin levels widely overlap in patients with hyponatraemia and emphasize the heterogeneity of the disease. Additionally, a variety of factors lead to unspecific copeptin elevations in the acute setting further complicating its interpretation. The broad use of copeptin as diagnostic marker in hyponatraemia and specifically to detect cancer-related disease in SIADH patients can, therefore, not be recommended.

EJE AWARD 2019: New diagnostic approaches for patients with polyuria polydipsia syndrome

Diabetes insipidus (DI), be it from central or nephrogenic origin, must be differentiated from secondary forms of hypotonic polyuria such as primary polydipsia. Differentiation is crucial since wrong treatment can have deleterious consequences. Since decades, the gold standard for differentiation has been the water deprivation test, which has limitations leading to an overall unsatisfying diagnostic accuracy. Furthermore, it is cumbersome for patients with a long test duration. Clinical signs and symptoms and MRI characteristics overlap between patients with DI and primary polydipsia. The direct test including vasopressin (AVP) measurement upon osmotic stimulation was meant to overcome these limitations, but failed to enter clinical practice mainly due to technical constraints of the AVP assay. Copeptin is secreted in equimolar amount to AVP but can easily be measured with a sandwich immunoassay. A high correlation between copeptin and AVP has been shown. Accordingly, copeptin mirrors the amount of AVP in the circulation and has led to a 'revival' of the direct test in the differential diagnosis of DI. We have shown that a baseline copeptin, without prior thirsting, unequivocally identifies patients with nephrogenic DI. In contrast, for the differentiation between central DI and primary polydipsia, a stimulated copeptin level of 4.9 pmol/L upon hypertonic saline infusion differentiates these two entities with a high diagnostic accuracy and is superior to the water deprivation test. Close sodium monitoring during the test is a prerequisite. Further new test methods are currently evaluated and might provide an even simpler way of differential diagnosis in the future.

Serum fatty acid binding protein 4 is positively associated with early stroke recurrence in nondiabetic ischemic stroke

Adipocyte fatty acid–binding protein (FABP4) played critical roles in metabolic syndrome, inflammatory responses and cardiovascular diseases. It aimed to investigate the associations of serum FABP4 levels with early stroke recurrence. This study included the 206 acute ischemic stroke patients hospitalized in our institution. Stroke recurrence events were assessed at the 3-month follow-up. The median of FABP level was 22.6 (IQR, 17.9-31.6) ng/mL in patients with stroke recurrence (N=36), which was higher than in patients without stroke recurrence [16.9 (IQR, 11.8-21.4) ng/mL] (P<0.001). As a continuous variable, the unadjusted and adjusted risk of stroke recurrence would be increased by 12% (OR=1.12 [95% CI 1.06–1.17], P<0.001) and 8% (1.08 [1.02–1.14], P=0.006) for every 1 ng/ml increment of FABP4. The Area under the curve (AUC) of serum FABP4 and NIH Stroke Scale (NIHSS) score for predicting stroke recurrence was 0.73 (95% CI: 0.64–0.82) and 0.72 (95% CI: 0.64–0.81), presenting no discriminating capacity (P=0.45). In the combining model, the AUC of NIHSS score was further improved to 0.77 by FABP4 (0.77; 95% CI: 0.69–0.85), which was significant (P=0.01). The risk of stroke recurrence can be predicted by elevated FABP4 levels in serum of nondiabetic patients with first-ever ischemic stroke.

Prognostic value of copeptin in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Recently, copeptin has been identified as a plasma prognosis marker in acute ischemic stroke and intracerebral hemorrhage (ICH). This study investigated the prognostic value of copeptin in the patients with aneurysmal subarachnoid hemorrhage(aSAH).

METHODS

In this retrospective study, 243 consecutive patients were included. Upon admission, plasma copeptin levels were measured by enzyme-linked immunosorbent assay. The end points were mortality and poor functional outcome (Glasgow Outcome Scale score of 1-3) after 3 months.

RESULTS

In 243 patients, 112 (46.1%) were male and median age was 58 years (IQR 49-68). Median copeptin plasma levels were 21.0 pmol/l (IQR 13.2-31.2). Copeptin levels increased with increasing severity of aSAH as defined by the World Federation of Neurological Surgeons (WFNS) score. Patients with a poor outcome and nonsurvivors had significantly increased copeptin levels on admission (P < .001 both). In the multivariate analysis, for each 1 pmol/l increase of plasma concentration of copeptin, the adjusted risk of poor outcomes and mortality would be increased by and 6% (1.06 [1.02-1.10], P < .001) and 9% (1.09 [1.03-1.13], P < .001), respectively. Receiver operating characteristics to predict functional outcome and mortality demonstrated areas under the curve of copeptin of 0.74 (95% confidence interval [CI], 0.67-0.81) and 0.81 (95% CI, 0.74-0.87), which was comparable with the WFNS score(P > .05) but superior to C-reactive protein and IL-6 (P < .01).

CONCLUSIONS

The data shows that copeptin levels may reliably predict short-term prognosis at its onset in aSAH patients.

A novel biomarker-based prognostic score in acute ischemic stroke: The CoRisk score

OBJECTIVES

To derive and externally validate a copeptin-based parsimonious score to predict unfavorable outcome 3 months after an acute ischemic stroke (AIS).

METHODS

The derivation cohort consisted of patients with AIS enrolled prospectively at the University Hospital Basel, Switzerland. The validation cohort was prospectively enrolled after the derivation cohort at the University Hospital of Bern and University Hospital Basel, Switzerland, as well as Frankfurt a.M., Germany. The score components were copeptin levels, age, NIH Stroke Scale, and recanalization therapy (CoRisk score). Copeptin levels were measured in plasma drawn within 24 hours of AIS and before any recanalization therapy. The primary outcome of disability and death at 3 months was defined as modified Rankin Scale score of 3 to 6.

RESULTS

Overall, 1,102 patients were included in the analysis; the derivation cohort contributed 319 patients, and the validation cohort contributed 783. An unfavorable outcome was observed among 436 patients (40%). For the 3-month prediction of disability and death, the CoRisk score was well calibrated in the validation cohort, for which the area under the receiver operating characteristic curve was 0.819 (95% confidence interval [CI] 0.787-0.849). The calibrated CoRisk score correctly classified 75% of patients (95% CI 72-78). The net reclassification index between the calibrated CoRisk scores with and without copeptin was 46% (95% CI 32-60).

CONCLUSIONS

The biomarker-based CoRisk score for the prediction of disability and death was externally validated, was well calibrated, and performed better than the same score without copeptin.

CLINICALTRIALSGOV IDENTIFIER

NCT00390962 (derivation cohort) and NCT00878813 (validation cohort).

The mean platelet volume on admission predicts unfavorable stroke outcomes in patients treated with IV thrombolysis

Purpose

The role of biomarkers in the prediction of acute ischemic stroke (AIS) outcome or response to thrombolytic therapy (with recombinant tissue plasminogen activator [rt-PA]) remains limited. The aim of this study was to evaluate whether mean platelet volume (MPV) could predict short-term functional outcome in patients with AIS following rt-PA treatment.

Patients and methods

This was a retrospective analysis of 237 AIS patients (mean age 71.04±0.8 years, 50.6% women) consecutively admitted to a tertiary care center between 2011 and 2015.

Results

The mean MPV in the cohort was 9.8±0.35 fL (lowest tertile <7.29 fL, median 7.29–8.8 fL, and highest tertile >8.8 fL). Patients in the lowest tertile compared to median and highest tertiles were less often dependent (modified Rankin scale [mRS] ≥3) at admission (87.2% vs 96.1% and 96.1%, respectively, P=0.04) and less often had a poor stroke outcome (mRS 4–6) at discharge (28.2% vs 55.3% and 44.7%, P<0.01). However, there was no significant difference between tertiles with regard to AIS etiology, CT (Alberta Stroke Program Early CT) score, frequency of stroke due to large artery occlusion, risk of secondary hemorrhage, and early neurologic deterioration. Multivariable analysis after adjustment for confounders showed that patients in the second and third tertiles had a significantly higher risk of poor stroke outcome (OR =1.9, 95% CI =1.01–4), lack of early improvement (OR =1.91, 95% CI =1.05–3.47), lower chance of good outcome (mRS 0–2; OR =0.38, 95% CI =0.18–0.78), or minor stroke at discharge (OR =0.47, 95% CI =0.26–0.84). Receiver operating characteristic analysis for prediction of poor stroke outcome showed that the optimal cut-off point of MPV was 8.8 fL (area under the curve 0.586 [0.512–0.659], P=0.03) with a sensitivity of 82.7% and a specificity of 43.9%.

Conclusion

Disabling or fatal ischemic stroke in thrombolyzed patients was observed more often in patients with high admission MPV. The prognostic value of MPV was independent of other well-defined individual risk factors.

IL-6 Plasma Levels Correlate With Cerebral Perfusion Deficits and Infarct Sizes in Stroke Patients Without Associated Infections

Introduction: We aimed to investigate several blood-based biomarkers related to inflammation, immunity, and stress response in a cohort of patients without stroke-associated infections regarding their predictive abilities for functional outcome and explore whether they correlate with MRI markers, such as infarct size or location. Methods: We combined the clinical and radiological data of patients participating in two observational acute stroke cohorts: the PREDICT and 1000Plus studies. The following blood-based biomarkers were measured in these patients: monocytic HLA-DR, IL-6, IL-8, IL-10, LBP, MRproANP, MRproADM, CTproET, Copeptin, and PCT. Multiparametric stroke MRI was performed including T2^*, DWI, FLAIR, TOF-MRA, and perfusion imaging. Standard descriptive sum statistics were used to describe the sample. Associations were analyzed using Fischer's exact test, independent samples t-test and Spearmans correlation, where appropriate. Results: Demographics and stroke characteristics were as follows: 94 patients without infections, mean age 68 years (SD 10.5), 32.2% of subjects were female, median NIHSS score at admission 3 (IQR 2-5), median mRS 3 months after stroke 1 (IQR 0-2), mean volume of DWI lesion at admission 5.7 ml (SD 12.8), mean FLAIR final infarct volume 10 ml (SD 14.9), cortical affection in 61% of infarctions. Acute DWI lesion volume on admission MRI was moderately correlated to admission/maximum IL-6 as well as maximum LBP. Extent of perfusion deficit and mismatch were moderately correlated to admission/maximum IL-6 levels. Final lesion volume on FLAIR was moderately correlated to admission IL-6 levels. Conclusion: We found IL-6 to be associated with several parameters from acute stroke MRI (acute DWI lesion, perfusion deficit, final infarct size, and affection of cortex) in a cohort of patients not influenced by infections. Clinical Trial Registration: www.ClinicalTrials.gov, identifiers NCT01079728 and NCT00715533.

Central noradrenaline transporter availability is linked with HPA axis responsiveness and copeptin in human obesity and non-obese controls

The central noradrenaline (NA) stress-response network co-mediates hypothalamic-pituitary-adrenal (HPA) axis activation and arginine-vasopressin (AVP) release. Dysregulation of these systems contributes to stress-related diseases such as human obesity, but their interrelation remains unclear. The study was aimed to test for the first time in vivo whether central noradrenergic activity quantitatively indexed by the availability of the presynaptic NA transporter (NAT) is associated with HPA axis responsiveness as measured with the combined dexamethasone suppression/corticotropin releasing hormone stimulation (dex/CRH) test and copeptin as a surrogate marker of the serum AVP tone in highly obese, otherwise, healthy individuals compared to age- and sex-matched non-obese, healthy controls. In order to assess central NAT availability, positron emission tomography (PET) was applied using the NAT-selective radiotracer S,S-[¹¹C]O-methylreboxetine (MRB) and correlated with curve indicators derived from the dex/CRH test (maximum, MAX, and area under the curve, AUC, for cortisol and adrenocorticotropic hormone, ACTH) as well as with copeptin. In non-obese controls, positive correlations were found between the NAT distribution volume ratios (DVR) of the orbitofrontal cortex (OFC) and the amygdala with the HPA response (OFC: ACTH_MAX r = 0.87, p = .001; cortisol_MAX r = 0.86, p = .002; amygdala: ACTH_MAX r = 0.86, p = .002; cortisol_MAX r = 0.79, p = .006), while in obesity, the hypothalamic DVR correlated inversely with the HPA axis response (cortisol_MAX, r = -0.66, p = .04) and with copeptin (r = -0.71, p = .02). This association of central NAT availability with HPA axis responsiveness and copeptin suggests a mechanistic interaction between noradrenergic transmission with HPA axis activity and the serum AVP system that differs between non-obese individuals with prefrontal-limbic involvement and obesity with a hypothalamic-centered relationship. Whether the latter finding contributes to obesogenic behavior needs to be further explored.

Serum leptin is associated with first-ever ischemic stroke, lesion size and stroke severity in a Chinese cohort

OBJECTIVE

Leptin may be associated with cardiovascular disease. We tested to determine whether leptin is a marker for first-ever acute ischemic stroke (AIS) in a nested case-referent study.

METHODS

Consecutive patients with first-ever AIS from May 2017 to December 2017 were included. Referents were matched for sex, age and body mass index. Serum leptin levels and routine tests were examined in both groups.

RESULTS

The median serum level of leptin in the stroke patients was 14.3 (interquartile range [IQR], 7.2-21.7) ng/ml, which was significantly higher (P < 0.001) than in the referents (10.7; 5.7-13.6 ng/ml). There was a positive correlation between serum level of leptin and National Institute of Health Stroke Scale score (r[Spearman] = 0.43, P < 0.001). In addition, serum leptin levels paralleled lesion size. Median serum level of leptin in patients with small lesions, medium lesions and large lesions was 7.3 (IQR, 5.3-14.3) ng/ml, 13.9 (IQR, 7.0-21.3) ng/ml, 20.5 (IQR, 12.4-32.7) ng/ml, respectively (analysis of variance: P < 0.001). In the univariate model matching for sex and age, leptin as a continuous variable was associated with AIS, after adjustment for possible confounders (odds ratio [OR] 1.07, 95% confidence interval [CI]: 1.04-1.11; P < 0.001). After adjusting for all other factors, leptin remained an independent stroke predictor with an adjusted OR of 1.03 (95% CI, 1.00-1.10; P = 0.006). Interestingly, the association between AIS and leptin level was more pronounced among men (adjusted OR = 1.05, 95% CI: 1.01-1.12; P < 0.001) when compared with women (adjusted OR = 1.03, 95% CI: 1.10-1.11; P = 0.009).

CONCLUSION

Serum leptin is associated with first-ever AIS, lesion size and stroke severity in a Chinese cohort.

Peripheral tumor necrosis factor-a-induced protein 8-like 2 mRNA level for predicting 3-month mortality of patients with acute ischemic stroke

Tumor necrosis factor-a-induced protein 8-like 2 (TIPE2) is a novel negative regulator for maintaining immune homeostasis. This study aimed to investigate TIPE2 mRNA in peripheral blood mononuclear cells for predicting 3-month functional outcomes and mortality of patients with acute ischemic stroke. A total of 182 consecutive patients were prospective collected, and there were 55 (30.2%) patients with unfavorable outcome and 33 (18.1%) patients died at the end of 3 months. The area under the operating characteristic curve (AUC) for TIPE2 mRNA was 0.810 (95% CI 0.733-0.886) for mortality and 0.740 (95% CI 0.662-0.818) for unfavorable outcome. The model incorporating National Institutes of Health Stroke Scale (NIHSS) plus TIPE2 showed significantly (P = 0.04) increased discrimination power (AUC = 0.925, 95% CI 0.874-0.976) for mortality than NIHSS (AUC = 0.882, 95% CI 0.833-0.932). Furthermore, NIHSS plus TIPE2 showed a significant improvement of both integrated discrimination index (IDI) and net reclassification index (NRI) as compared with NIHSS (IDI = 0.224, 95% CI 0.150-0.299, P < 0.001; NRI = 1.119, 95% CI 0.810-1.429, P < 0.001). The pruned time-dependent tree analysis showed that patients with NIHSS ≥ 5.5 and TIPE2 mRNA < 5.2 had rather high 3-month mortality. In conclusion, TIPE2 mRNA improved the diagnostic value of NIHSS score, and patients with NIHSS ≥ 5.5 and TIPE2 mRNA < 5.2 had high 3-month mortality.

Serum Copeptin Levels Predict Clinical Outcomes After Successful Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction

BACKGROUND

Serum copeptin has been demonstrated to be useful in early risk stratification and prognostication of patients with acute myocardial infarction (AMI). However, the prognostic value of copeptin after percutaneous coronary intervention (PCI) for clinical outcomes remains uncertain. We investigated the prognostic role of serum copeptin levels immediately after successful PCI as a prognostic marker for major adverse cardiac events (MACE; comprising death, repeat PCI, recurrent MI, or coronary artery bypass grafting) in patients with AMI.

METHODS

A retrospective study was performed in 149 patients with AMI who successfully received PCI. Serum copeptin levels were analyzed in blood samples collected immediately after PCI. The association between copeptin levels and MACE during the follow-up period was evaluated.

RESULTS

MACE occurred in 34 (22.8%) patients during a median follow-up of 30.1 months. MACE patients had higher copeptin levels than non-MACE patients did. Multiple logistic regression analysis showed that the increase in serum copeptin levels was associated with increased MACE incidence (odds ratio=1.6, P=0.005).

CONCLUSIONS

A high level of serum copeptin measured immediately after PCI was associated with MACE in patients with AMI during long-term follow-up. Serum copeptin levels can serve as a prognostic marker in patients with AMI after successful PCI.

Time course of copeptin during a model of experimental pain and hyperalgesia: A randomised volunteer crossover trial

BACKGROUND

A reliable biomarker for quantifying pain or hyperalgesia has yet to be found. A surrogate marker of arginine vasopressin, copeptin, is elevated in a number of states of physiological and psychological stress and may have a role in quantifying pain and/or hyperalgesia.

OBJECTIVES

To evaluate copeptin as a biomarker for pain or hyperalgesia developing after 120 min of sustained electrical stimulation.

DESIGN

Secondary analysis of a randomised, double-blinded, crossover trial.

SETTING

Single, tertiary university hospital from September 2014 to January 2015.

PARTICIPANTS

A total of 16 healthy, opioid-naïve white men with no confounding medication or history of pain.

INTERVENTIONS

Copeptin and cortisol were measured five times during an established model of transdermal electrical stimulation designed to assess pain and hyperalgesia.

MAIN OUTCOME MEASURES

The primary outcome was the change in copeptin concentration after 120 min of sustained electrical stimulation. Secondary outcomes were copeptin and cortisol concentrations after a subsequent period of rest and analyses of copeptin and cortisol concentrations were made in high-dose and low-dose fentanyl groups separately.

RESULTS

Total copeptin concentrations were not significantly elevated after 120 min [9.15 pmol l (interquartile ranges (IQR), 3.45 to 35.45 pmol l); P = 0.150] compared with baseline [6.15 pmol l (IQR, 3.60 to 10.62 pmol l)]. In the high-dose fentanyl group, there was a significant increase in copeptin within individuals [P = 0.001; median, 37.9 pmol l (IQR, 8.1 to 62 pmol l)] after 120 min, and in the low-dose fentanyl group a significant decrease in copeptin concentrations within individuals [P = 0.006; median, 4.7 pmol l (IQR, 3.13 to 9.35 pmol l)]. No correlation between copeptin concentration and either the area under the pain curve or area under the hyperalgesia curve could be found, indicating that the observed differences may be due to other fentanyl-mediated effects.

CONCLUSION

Copeptin concentrations do not appear to be associated directly with pain and hyperalgesia. Instead, some fentanyl-mediated effect or effects appear to have greatly increased copeptin concentrations from baseline to 120 min.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02252458.

Polyuria-polydipsia syndrome: a diagnostic challenge

The main determinants for the maintenance of water homeostasis are the hormone arginine vasopressin (AVP) and thirst. Disturbances in these regulatory mechanisms can lead to polyuria-polydipsia syndrome, which comprises of three different conditions: central diabetes insipidus (DI) due to insufficient secretion of AVP, nephrogenic DI caused by renal insensitivity to AVP action and primary polydipsia due to excessive fluid intake and consequent physiological suppression of AVP. It is crucial to determine the exact diagnosis because treatment strategies vary substantially. To differentiate between the causes of the polyuria-polydipsia syndrome, a water deprivation test combined with desmopressin administration is the diagnostic 'gold standard'. Thereby, AVP activity is indirectly evaluated through the measurement of urine osmolality after prolonged dehydration. However, this test has several limitations and may fail to distinguish precisely between patients with primary polydipsia and mild forms of central and nephrogenic DI. The direct measurement of AVP during the water deprivation test, which was reported in the 1980s, has not been widely adopted due to availability, assay issues and diagnostic performance. Recently, copeptin, the c-terminal portion of the larger precursor peptide of AVP, has been evaluated in the setting of polyuria-polydipsia syndrome and appears to be a useful candidate biomarker for the differential diagnosis. A standardised method for the water deprivation test is presented as part of a joint initiative of the Endocrine Society of Australia, the Australasian Association of Clinical Biochemists and the Royal College of Pathologists of Australasia to harmonise dynamic endocrine tests across Australia.

Serum neurofilament light: A biomarker of neuroaxonal injury after ischemic stroke

OBJECTIVE

To explore the utility of serum neurofilament light chain (NfL) as a biomarker for primary and secondary neuroaxonal injury after ischemic stroke (IS) and study its value for the prediction of clinical outcome.

METHODS

We used an ultrasensitive single-molecule array assay to measure serum NfL levels in healthy controls (n = 30) and 2 independent cohorts of patients with IS: (1) with serial serum sampling at hospital arrival (n = 196), at days 2, 3, and 7 (n = 89), and up to 6 months post stroke; and (2) with standardized MRI at baseline and at 6 months post stroke, and with cross-sectional serum sampling at 6 months (n = 95). We determined the temporal profile of serum NfL levels, their association with imaging markers of neuroaxonal injury, and with clinical outcome.

RESULTS

Patients with IS had higher serum NfL levels compared with healthy controls starting from admission until 6 months post stroke. Serum NfL levels peaked at day 7 (211.2 pg/mL [104.7-442.6], median [IQR]) and correlated with infarct volumes (day 7: partial r = 0.736, p = 1.5 × 10^-15). Six months post stroke, patients with recurrent ischemic lesions on MRI (n = 19) had higher serum NfL levels compared to those without new lesions (n = 76, p = 0.002). Serum NfL levels 6 months post stroke further correlated with a quantitative measure of secondary neurodegeneration obtained from diffusion tensor imaging MRI (r = 0.361, p = 0.001). Serum NfL levels 7 days post stroke independently predicted modified Rankin Scale scores 3 months post stroke (cumulative odds ratio [95% confidence interval] = 2.35 [1.60-3.45]; p = 1.24 × 10^-05).

CONCLUSION

Serum NfL holds promise as a biomarker for monitoring primary and secondary neuroaxonal injury after IS and for predicting functional outcome.

Plasma Unesterified Fatty-Acid Profile Is Dramatically and Acutely Changed under Ischemic Stroke in the Mouse Model

Although plasma biomarkers would facilitate rapid and accurate diagnosis of ischemic stroke for immediate treatment, no such biomarkers have been developed to date. In the present study, we tested our hypothesis that plasma unesterified fatty acids (FFA) are altered at early stages of acute ischemic stroke. Plasma was collected from mice 2 h after the permanent middle cerebral artery occlusion (pMCAo) onset, as well as from sham operated and control animals. After 2 h, pMCAo significantly changed the plasma FFA profile with the most dramatic 2- to 3-fold relative increase in very long n-3 and n-6 FFA including 20:4n-6, 22:4n-6, 22:5n-6, and 22:6n-3. Changes in the plasma FFA profile are consistent with FFA liberation from brain phospholipid hydrolyzed under ischemic insult. These results identify, for the first time, the plasma FFA profile as a potential biomarker for an early ischemic stroke within the therapeutic window for thrombolytic treatment. Further studies are required to confirm its specificity and sensitivity in clinical settings.

Hyponatremia and activation of vasopressin secretion are both independently associated with 30-day mortality: results of a multicenter, observational study

BACKGROUND

Hyponatremia is a common feature of acute illness and associated with increased mortality. This may be explained by a stress-mediated activation of the vasopressin system with an increase in free-water reabsorption.

OBJECTIVES

To investigate whether the association between hyponatremia and mortality could be explained by activation of the vasopressin system.

METHODS

We prospectively enrolled adult, medical patients seeking emergency care in three centres in Switzerland, France and the United States. We investigated associations between admission plasma sodium and copeptin, a stable portion of the vasopressin-precursor peptide, with 30-day mortality. We performed uni- and multivariate regression analysis.

RESULTS

Of 6962 included patients, 18% had hyponatremia (sodium ≤135 mmol L^-1 ), which doubled their risk for mortality compared to patients with normonatremia (8.3% vs. 3.8%). This association was confirmed in a multivariate-adjusted logistic regression analysis [adjusted odds ratio (OR) 1.47, 95% CI 1.12-1.93, P = 0.005]. Vasopressin levels, mirrored by copeptin, were also increased in nonsurvivors and strongly associated with mortality (adjusted OR 3.42, 95% CI 2.76-4.25, P < 0.001). The association between hyponatremia and mortality remained unchanged when adding copeptin levels to the regression model (fully adjusted OR 1.53, 95% CI 1.16-2.00, P = 0.002).

CONCLUSION

This prospective study including medical patients upon emergency room admission found hyponatremia as well as an activation of the vasopressin system to be independently associated with mortality. This suggests that stress- and vasopressin-independent mechanisms are responsible for the association of low sodium levels with mortality.

Plasma copeptin levels in patients with restless legs syndrome

OBJECTIVES

Copeptin, the C-terminal fragment of antidiuretic hormone, is a new biomarker that has been found to be elevated in several disorders and could be related with prognosis. This study aimed to compare plasma copeptin levels in patients with restless legs syndrome (RLS) with healthy individuals and to investigate whether plasma copeptin levels were associated with the severity of disease.

MATERIAL AND METHODS

41 patients with primary RLS, who were followed in Bakirkoy Psychiatry and Neurology Research and Training Hospital and 41 age- and sex-matched healthy individuals were included into the study. RLS patients were divided into subgroups as mild-moderate, severe, and very severe according to the severity of symptoms. Sleep quality and excessive daytime sleepiness were determined according to Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale, respectively, and sleep quality scores were analyzed statistically among the groups divided according to disease severity. Copeptin levels in all the patients were compared to the controls. RLS subgroups were compared with each other to evaluate association between copeptin levels and disease severity.

RESULTS

Plasma copeptin levels in RLS patients were significantly higher than controls (P < .001). However, there was no association between copeptin levels and disease severity. Excessive daytime sleepiness was found as 14.63% and low sleep quality as 68.29% in patients.

CONCLUSIONS

Hypothalamic-pituitary-adrenal axis activation and sympathetic hyperactivity in RLS might be responsible for increased Antidiuretic hormone (ADH) and copeptin release. We think that copeptin might have a potential role in the pathogenesis of RLS and be a biomarker for this disease.

Copeptin levels and commonly used laboratory parameters in hospitalised patients with severe hypernatraemia - the "Co-MED study"

Background

Hypernatraemia is common in inpatients and is associated with substantial morbidity. Its differential diagnosis is challenging, and delayed treatment may have devastating consequences. The most important hormone for the regulation of water homeostasis is arginine vasopressin, and copeptin, the C-terminal portion of the precursor peptide of arginine vasopressin, might be a reliable new parameter with which to assess the underlying cause of hypernatraemia.

Methods

In this prospective, multicentre, observational study conducted in two tertiary referral centres in Switzerland, 92 patients with severe hyperosmolar hypernatraemia (Na⁺ > 155 mmol/L) were included. After a standardised diagnostic evaluation, the underlying cause of hypernatraemia was identified and copeptin levels were measured.

Results

The most common aetiology of hypernatraemia was dehydration (DH) (n = 65 [71%]), followed by salt overload (SO) (n = 20 [22%]), central diabetes insipidus (CDI) (n = 5 [5%]) and nephrogenic diabetes insipidus (NDI) (n = 2 [2%]). Low urine osmolality was indicative for patients with CDI and NDI (P < 0.01). Patients with CDI had lower copeptin levels than patients with DH or SO (both P < 0.01) or those with NDI. Copeptin identified CDI with an AUC of 0.99 (95% CI 0.97–1.00), and a cut-off value ≤ 4.4pmol/L showed a sensitivity of 100% and a specificity of 99% to predict CDI. Similarly, urea values were lower in CDI than in DH or SO (P < 0.05 and P < 0.01, respectively) or NDI. The AUC for diagnosing CDI was 0.98 (95% CI 0.96–1.00), and a cut-off value < 5.05 mmol/L showed high specificity and sensitivity for the diagnosis of CDI (98% and 100%, respectively). Copeptin and urea could not differentiate hypernatraemia induced by DH from that induced by SO (P = 0.66 and P = 0.30, respectively).

Conclusions

Copeptin and urea reliably identify patients with CDI and are therefore helpful tools for therapeutic management in patients with severe hypernatraemia.

Trials registration

ClinicalTrials.gov, NCT01456533. Registered on 20 October 2011.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1955-7) contains supplementary material, which is available to authorized users.

Release and Decay Kinetics of Copeptin vs AVP in Response to Osmotic Alterations in Healthy Volunteers

CONTEXT

Copeptin is the C-terminal fragment of the arginine vasopressin (AVP) prohormone whose measurement is more robust than that of AVP. Similar release and clearance characteristics have been suggested promoting copeptin as a surrogate marker.

OBJECTIVE

To characterize the physiology of osmotically regulated copeptin release and its half-life in direct comparison with plasma AVP.

DESIGN

Ninety-one healthy volunteers underwent a standardized three-phase test protocol including (1) osmotic stimulation into the hypertonic range by hypertonic-saline infusion followed by osmotic suppression via (2) oral water load and (3) subsequent glucose infusion. Plasma copeptin, AVP, serum sodium, and osmolality levels were measured in regular intervals.

RESULTS

In phase 1, an increase in median osmotic pressure [289 (286; 291) to 311 (309; 314) mOsm/kg H2O] caused similar release kinetics of plasma copeptin [4 (3.1; 6) to 29.3 (18.6; 48.2) pmol/L] and AVP [1 (0.7; 1.6) to 10.3 (6.8; 18.8) pg/mL]. Subsequent osmotic suppression to 298 (295; 301) mOsm/kg at the end of phase 3 revealed markedly different decay kinetics between both peptides-an estimated initial half-life of copeptin being approximately 2 times longer than that of AVP (26 vs 12 minutes).

CONCLUSION

Copeptin is released in equimolar amounts with AVP in response to osmotic stimulation, suggesting its high potential as an AVP surrogate for differentiation of osmotic disorders. Furthermore, we here describe the decay kinetics of copeptin in response to osmotic depression enabling to identify a half-life for copeptin in direct comparison with AVP.

Serum neurofilament light chain in patients with acute cerebrovascular events

BACKGROUND AND PURPOSE

Serum neurofilaments are markers of axonal injury. We addressed their diagnostic and prognostic role in acute ischemic stroke (AIS) and transient ischemic attack (TIA).

METHODS

Nested within a prospective cohort study, we compared levels of serum neurofilament light chain (sNfL) drawn within 24 h from symptom onset in patients with AIS or TIA. Patients without magnetic resonance imaging on admission were excluded. We assessed whether sNfL was associated with: (i) clinical severity on admission, (ii) diagnosis of AIS vs. TIA, (iii) infarct size on admission magnetic resonance diffusion-weighted imaging (MR-DWI) and (iv) functional outcome at 3 months.

RESULTS

We analyzed 504 patients with AIS and 111 patients with TIA. On admission, higher National Institutes of Health Stroke Scale (NIHSS) scores were associated with higher sNfL: NIHSS score < 7, 13.1 pg/mL [interquartile range (IQR), 5.3-27.8]; NIHSS score 7-15, 16.7 pg/mL (IQR, 7.4-34.9); and NIHSS score > 15, 21.0 pg/mL (IQR, 9.3-40.4) (P = 0.01). Compared with AIS, patients with TIA had lower sNfL levels [9.0 pg/mL (95% confidence interval, 4.0-19.0) vs. 16.0 pg/mL (95% confidence interval, 7.3-34.4), P < 0.001], also after adjusting for age and NIHSS score (P = 0.006). Among patients with AIS, infarct size on admission MR-DWI was not associated with sNfL, either in univariate analysis (P = 0.15) or after adjusting for age and NIHSS score on admission (P = 0.56). Functional outcome 3 months after stroke was not associated with sNfL after adjusting for established predictors.

CONCLUSIONS

In conclusion, among patients admitted within 24 h of AIS or TIA onset, admission sNfL levels were associated with clinical severity on admission and TIA diagnosis, but not with infarct size on MR-DWI acquired on admission or functional outcome at 3 months.

Midregional proatrial natriuretic peptide improves risk stratification after ischemic stroke

Objective

To validate midregional proatrial natriuretic peptide (MR-proANP) for outcome prediction and diagnosis of cardioembolic stroke etiology compared to established clinical variables.

Methods

In this prospective multicenter cohort study, we quantified MR-proANP levels in ischemic stroke patients within 24 hours of onset. Primary outcome measures were 90-day mortality, unfavorable functional outcome (modified Rankin Scale score >2), and cardioembolic stroke etiology diagnosed during hospitalization.

Results

Of 788 included patients, 783 completed their 90-day follow-up, and 118 patients (15%) died. After full adjustment, MR-proANP levels were associated with 90-day mortality (adjusted hazard ratio 6.12, 95% confidence interval [CI] 2.36–15.84, p = 0.01) and functional outcome (adjusted odds ratio [aOR] 2.46, 95% CI 1.05–5.74, p = 0.038). For mortality prediction, adding MR-proANP to the regression model increased its discriminatory accuracy, and the continuous net reclassification index (cNRI) was 49% (95% CI 26%–78%, p < 0.001). For functional outcome, there was no significant improvement in discrimination or reclassification. Cardioembolic stroke etiology and the diagnosis of atrial fibrillation at hospital discharge were associated with MR-proANP with an aOR of 2.10 (95% CI 1.11–3.97, p = 0.02) and 18.35 (95% CI 7.94–42.45, p < 0.001), respectively. The cNRI of MR-proANP for cardioembolic stroke etiology was not significant, as opposed to atrial fibrillation (78%, 95% CI 60%–89%, p < 0.001). MR-proANP levels ≥289 pmol/L had a specificity of 86% and sensitivity of 48% for the diagnosis of atrial fibrillation.

Conclusion

MR-proANP is a newly validated blood biomarker providing additional prognostic information for mortality after stroke. Higher MR-proANP levels were associated with cardioembolic stroke etiology and, even more strongly, atrial fibrillation.

Cortisol Outperforms Novel Cardiovascular, Inflammatory, and Neurohumoral Biomarkers in the Prediction of Outcome in Acute Pancreatitis

OBJECTIVES

The aims of this study were to assess whether copeptin, pro-atrial natriuretic peptide, proadrenomedullin, and cortisol are associated with disease severity in patients with acute pancreatitis (AP) and to compare their ability in predicting organ failure or death.

METHODS

From April 2011 to January 2015, 142 patients with AP were included in this prospective single-center study and observed for 4 days. Disease severity was rated by the Atlanta 1992 and 2012 criteria and organ failure by the modified Marshall score. The aforementioned laboratory markers, C-reactive protein, and procalcitonin were measured.

RESULTS

Patients with moderate to severe AP showed significantly higher plasma concentrations of all biomarkers than did those with mild AP. Overall, 30 organ failures or deaths occurred. All biomarkers except cortisol had only modest discriminatory ability, with areas under the receiver operating characteristic curve (AUCs) between 0.44 and 0.66. Cortisol showed an AUC of 0.78 compared with the Acute Physiology and Chronic Health Evaluation II score with an AUC of 0.75.

CONCLUSIONS

Cortisol was the best predictor of organ failure or death. All biomarkers were associated with disease severity to a similar degree as C-reactive protein, the criterion-standard marker in AP. Further studies are warranted to define their clinical role.

Elevated Lipoprotein (a) and Risk of Poor Functional Outcome in Chinese Patients with Ischemic Stroke and Type 2 Diabetes

The aim of this study was to evaluate the short-term prognostic value of early measurement of serum lipoprotein (a) [Lp(a)] levels in Chinese patients with type 2 diabetes (T2D) and acute ischemic stroke (AIS). The study population comprised 232 consecutive patients with an AIS diagnosis complicated with T2D. Functional outcome was obtained on month 3 according to the modified Rankin Scale (mRS). Unfavorable functional outcome was defined as a mRS score of 3 to 6 points. The prognostic value of Lp(a) at admission to predict the unfavorable functional outcome 3 months after stroke onset was compared with the National Institutes of Health Stroke Scale score and other known outcome predictors. The Lp(a) levels in those patients were obtained with a median value of 16.8 mg/dl (IQR, 9.5-34.4 mg/dl). At 3-month follow-up, an unfavorable functional outcome was found in 86 patients (37.1%). In multivariate models comparing the second (Q2), third, and fourth quartiles against the first quartile of Lp(a), concentrations of Lp(a) in Q2, Q3, and Q4 were associated with unfavorable outcome, and increased risk of unfavorable outcome by 42, 131, and 211%. Interestingly, an elevated Lp(a, > 30 mg/dl) was also associated with unfavorable outcome, and with adjusted OR of 2.25 (95% CI 1.39-3.68). The AUC was significantly increased by adding Lp(a) to established risk factors (difference, 0.041 [95% CI, 0.034-0.053]; P = 0.02). The addition of Lp(a) to established risk factors significantly improved net reclassification improvement and integrated discrimination improvement. Higher Lp(a) levels at admission were associated with increased risk of unfavorable functional outcome and might be useful in identifying stroke patients with T2D at risk for unfavorable functional outcome for early prevention strategies.

MicroRNA 150-5p Improves Risk Classification for Mortality within 90 Days after Acute Ischemic Stroke

Background and Purpose

Micro ribonucleic acid-150-5p (miR-150-5p) regulates proinflammatory cytokines as well as vessel integrity. We evaluated the incremental prognostic value of logarithm (log) of miR-150-5p plasma levels after ischemic stroke.

Methods

In a prospective cohort study, levels of miR-150-5p were measured within 72 hours of symptom onset in 329 ischemic stroke patients. The outcome measures were unfavorable functional outcome (assessed by the modified Rankin Scale score >2) and mortality within 90 days. Logistic regression and Cox proportional hazards models were fitted to estimate odds ratio (OR), respectively hazard ratio (HR) and 95% confidence interval (CI) for the association between log-miR-150-5p and the outcome measures. The discriminatory accuracy was assessed with the area under the receiver-operating-characteristic curve (AUC) and the incremental prognostic value was estimated with the net reclassification index.

Results

After adjusting for demographic and vascular risk factors, lower log-miR-150-5p levels were independently associated with mortality (HR 0.21 [95% CI, 0.08–0.51], P=0.001) but not functional outcome (OR 1.10 [95% CI, 0.54–2.25], P=0.79). Adding log-miR-150-5p improved the discriminatory accuracy of the best multivariate model to predict mortality from an AUC of 0.91 (95% CI, 0.88–0.95) to 0.92 (95% CI, 0.88–0.96 Likelihood-ratio test-P<0.001), and resulted in a net reclassification index of 37.3% (95% CI, 0.28–0.52).

Conclusions

In patients with ischemic stroke, log-miR-150-5p is a novel prognostic biomarker, highly associated with mortality within 90 days, improving risk classification beyond traditional risk factors.

Prognostic utility of neuroinjury biomarkers in post out-of-hospital cardiac arrest (OHCA) patient management

Despite aggressive intervention, patients who survive an out-of-hospital cardiac arrest (OHCA) generally have very poor prognoses, with nationwide survival rates of approximately 10-20%. Approximately 90% of survivors will have moderate to severe neurological injury ranging from moderate cognitive impairment to brain death. Currently, few early prognostic indicators are considered reliable enough to support patients' families and clinicians' in their decisions regarding medical futility. Blood biomarkers of neurological injury after OHCA may be of prognostic value in these cases. When most bodily tissues are oxygen-deprived, cellular metabolism switches from aerobic to anaerobic respiration. Neurons are a notable exception, however, being dependent solely upon aerobic respiration. Thus, after several minutes without circulating oxygen, neurons sustain irreversible damage, and certain measurable biomarkers are released into the circulation. Prior studies have demonstrated value in blood biomarkers in prediction of survival and neurologic impairment after OHCA. We hypothesize that understanding peptide biomarker kinetics in the early return of spontaneous circulation (ROSC) period, especially in the setting of refractory cardiac arrest, may assist clinicians in determining prognosis earlier in acute resuscitation. Specifically, during and after immediate resuscitation and return of ROSC, clinicians and families face a series of important questions regarding patient prognosis, futility of care and allocation of scarce resources such as the early initiation of extracorporeal cardiopulmonary resuscitation (ECPR). The ability to provide early prognostic information in this setting is highly valuable. Currently available, as well as potential biomarkers that could be good candidates in prognostication of neurological outcomes after OHCA or in the setting of refractory cardiac arrest will be reviewed and discussed.

Circulating FABP4 (Fatty Acid-Binding Protein 4) Is a Novel Prognostic Biomarker in Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

FABP4 (fatty acid-binding protein 4) is an intracellular lipid chaperone involved in coordination of lipid transportation and atherogenesis. This study aimed at observing the effect of FABP4 on the 3-month outcomes in Chinese patients with acute ischemic stroke.

METHODS

In a prospective multicenter observational study, serum concentrations of FABP4 were on admission measured in plasma of 737 consecutive patients with acute ischemic stroke. Serum concentrations of FABP4, National Institutes of Health Stroke Scale score, and conventional risk factors were evaluated to determine their value to predict functional outcome and mortality within 3 months.

RESULTS

During follow-up, an unfavorable functional outcome was found in 260 patients (35.3%), and 94 patients (12.8%) died. In multivariate models comparing the third and fourth quartiles to the first quartile of FABP4, the concentrations of FABP4 were associated with poor functional outcome and mortality. Compared with the reference category (Q1-Q3), the concentrations of FABP4 in Q4 had a relative risk of 4.77 (95% confidence interval [CI], 2.02-8.15; P<0.001) for poor functional outcome and mortality (odds ratio, 6.15; 95% CI, 3.43-12.68) after adjusting for other significant outcome predictors in univariate logistic regression analysis. Receiver-operating characteristic curves to predict poor functional outcome and mortality demonstrated areas under the curve of FABP4 of 0.78 (95% CI, 0.75-0.82) and 0.83 (95% CI, 0.79-0.88), which improved the prognostic accuracy of National Institutes of Health Stroke Scale score with combined areas under the curve of 0.83 (95% CI, 0.76-0.89; P<0.01) and 0.86 (95% CI, 0.81-0.92), respectively.

CONCLUSIONS

Data show that FABP4 is a novel independent prognostic marker improving the currently used risk stratification of stroke patients.

Copeptin and NT-proBNP for prediction of all-cause and cardiovascular death in ischemic stroke

OBJECTIVE

To evaluate long-term mortality in patients with acute ischemic stroke (AIS) by exploring the correlation between death and plasma concentrations of copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in a cohort study.

METHODS

In a prospective, multicenter observational study of 4,215 patients with AIS, copeptin and NT-proBNP levels were measured with a standardized method when patients were admitted to hospital. The primary endpoint was all-cause mortality or cardiovascular disease (CVD) mortality within 1 year.

RESULTS

During a follow-up period, 906 patients (20.1%, 95% confidence interval [CI] 18.9-21.2) died, including 589 cases of CVD mortality (13.1%, 95% CI 12.1-14.0). With the use of a multivariate analysis, both markers were found to have prognostic value in the same model (CVD mortality: odds ratio [OR] for fourth quartile of copeptin and NT-proBNP 1.68 and 2.58, 95% CI 1.22-2.49 and 1.76-4.05, respectively; all-cause mortality: OR for fourth quartile of copeptin and NT-proBNP 1.48 and 2.47, 95% CI 1.22-2.03 and 1.68-3.95, respectively). In a receiver operating characteristics analysis of CVD mortality, the area under the curve varied from 0.80 to 0.83 (95% CI 0.79-0.87) when the index of NT-proBNP was added and increased to 0.86 (95% CI 0.83-0.90) when both markers were added.

CONCLUSIONS

Copeptin and NT-proBNP may be useful independent prognostic markers of all-cause or CVD mortality in Chinese patients with AIS.

Post-dexamethasone serum copeptin corresponds to HPA axis responsiveness in human obesity

CONTEXT

Increased activities of the arginine-vasopressin (AVP) system and the hypothalamic-pituitary-adrenal (HPA) axis were shown to be associated with human obesity, but relationships between these systems in obesity remain unclear.

OBJECTIVES

To assess HPA axis responsiveness and its relation to serum concentrations of the AVP-surrogate copeptin in subjects with obesity (OB) in comparison to non-obesity controls (NOC).

METHODS

In a cross-sectional monocentric study, thirty-nine OB (f/m 25/14; age 36.5±10.0years; body mass index, BMI, 41.5±4.7kg/m²) were compared to twenty-two NOC (f/m 12/10; age 35.3±8.5years; BMI 23.1±2.4kg/m²), matched for age and sex. All individuals underwent the combined dexamethasone/CRH test.

MAIN OUTCOME MEASURES

Plasma ACTH and cortisol curve indicators derived from the dex/CRH test (post-CRH concentrations 30min after 100μg CRH; maximum concentration, MAX; area-under-the-curve, AUC; ACTH/cortisol ratios). Copeptin was assessed in 1500h samples of the dex/CRH test (after 1.5mg of oral dexamethasone, prior to CRH administration).

RESULTS

Copeptin serum concentrations were higher in OB (median [IQR]: OB 4.62 [2.60-5.88] vs. NOC 3.04 [2.52-4.29] pmol/l, P=0.04). Correspondingly, OB showed higher post-CRH cortisol concentrations (OB: 51.5 [25.9-159.3] vs. NOC: 28.6 [20.0-41.6] nmol/l, P=0.01) and a lower post-CRH ACTH/cortisol ratio (OB: 0.028 [0.016-0.053] vs. NOC: 0.048 [0.034-0.070] pmol/nmol, P<0.01). Serum copeptin was significantly associated with HPA responsiveness in OB (post-CRH ACTH: R=0.42, P<0.01), driven by OB men (post-CRH ACTH: R=0.76, P<0.01, post-CRH cortisol: R=0.64, P=0.02). All associations withstand adjustments for BMI and age.

CONCLUSIONS

The association between increased copeptin with ACTH and cortisol release suggests a potential mechanistic interaction of the AVP system with HPA activation in human obesity. The relation of copeptin and HPA responsiveness should be further validated in situations with pronounced HPA activation, such as depression or multiple sclerosis.

Evaluation of copeptin and commonly used laboratory parameters for the differential diagnosis of profound hyponatraemia in hospitalized patients: 'The Co-MED Study'

OBJECTIVE

Hyponatraemia is common and its differential diagnosis is challenging. Commonly used diagnostic algorithms have limited diagnostic accuracy. Copeptin, the c-terminal portion of the precursor peptide of arginine vasopressin might help in the differential diagnosis of hyponatraemia.

DESIGN

Prospective multicentre observational study.

PATIENTS/METHODS

A total of 298 patients admitted with profound hypoosmolar hyponatraemia (Na < 125 mmol/l) were evaluated. Three experts uninvolved in the patients' care determined the aetiology of hyponatraemia after standardized diagnostic evaluation.

RESULTS

Hyponatraemia differential diagnoses were as follows: syndrome of inappropriate antidiuresis (SIAD), 106 patients (35·6%); 'diuretic-induced', 72 (24·2%); 'hypovolaemic', 59 (19·8%); 'hypervolaemic', 33 (11·1%); primary polydipsia (PP), 24 (8·1%); and cortisol deficiency, 4 (1·3%). Copeptin levels <3·9 pmol/l identified patients with PP with high specificity (91%). Further, copeptin levels >84 pmol/l were highly predictive for hypovolaemic hyponatraemia (specificity: 90%). Urinary sodium levels and copeptin/urinary sodium ratio in patients with SIAD were higher and lower as compared to other hyponatraemia aetiologies (P < 0·0001). However, the specificity to identify SIAD was moderate for both parameters (31% and 61%). Fractional uric acid excretion (FE_UA ) and fractional urea excretion (FE_urea ) were higher in patients with SIAD compared to other hyponatraemia aetiologies (both P < 0·0001). FE_urea values >55% and FE_UA values >12% had a specificity of 96% and 77% to detect patients with SIAD. These results remained similar after excluding patients taking diuretics.

CONCLUSIONS

Overall, there is only limited diagnostic utility of copeptin in the differential diagnosis of profound hyponatraemia. Very low copeptin levels are seen in patients with PP and highest copeptin levels in hypovolaemic hyponatraemia. To discriminate between SIAD and other hyponatraemia aetiologies, FE_urea and FE_UA levels are valuable irrespective of diuretics use.

Copeptin for risk stratification in non-traumatic headache in the emergency setting: a prospective multicenter observational cohort study

BACKGROUND

In the emergency setting, non-traumatic headache is a benign symptom in 80% of cases, but serious underlying conditions need to be ruled out. Copeptin improves risk stratification in several acute diseases. Herein, we investigated the value of copeptin to discriminate between serious secondary headache and benign headache forms in the emergency setting.

METHODS

Patients presenting with acute non-traumatic headache were prospectively enrolled into an observational cohort study. Copeptin was measured upon presentation to the emergency department. Primary endpoint was serious secondary headache defined by a neurologic cause requiring immediate treatment of the underlying disease. Secondary endpoint was the combination of mortality and hospitalization within 3 months. Two board-certified neurologist blinded to copeptin levels verified the endpoints after a structured 3-month-telephone interview.

RESULTS

Of the 391 patients included, 75 (19%) had a serious secondary headache. Copeptin was associated with serious secondary headache (OR 2.03, 95%CI 1.52-2.70, p < 0.0001). Area under the curve (AUC) for copeptin to identify the primary endpoint was 0.70 (0.63-0.76). After adjusting for age > 50, focal-neurological abnormalities, and thunderclap onset of symptoms, copeptin remained an independent predictive factor for serious secondary headache (OR 1.74, 95%CI 1.26-2.39, p = 0.001). Moreover, copeptin improved the AUC of the multivariate logistic clinical model (p-LR-test < 0.001). Even though copeptin values were higher in patients reaching the secondary endpoint, this association was not significant in multivariate logistic regression.

CONCLUSIONS

Copeptin was independently associated with serious secondary headache as compared to benign headaches forms. Copeptin may be a promising novel blood biomarker that should be further validated to rule out serious secondary headache in the emergency department.

TRIAL REGISTRATION

Study Registration on 08/02/2010 as NCT01174901 at clinicaltrials.gov.

Orthostatic Challenge Shifts the Hemostatic System of Patients Recovered from Stroke toward Hypercoagulability

Aims: The objective of our study was to assess the effects of orthostatic challenge on the coagulation system in patients with a history of thromboembolic events and to assess how they compared with age-matched healthy controls. Methods: Twenty-two patients with histories of ischemic stroke and 22 healthy age-matched controls performed a sit-to-stand test. Blood was collected prior to- and at the end of- standing in the upright position for 6 min. Hemostatic profiling was performed by determining thrombelastometry and calibrated automated thrombogram values, indices of thrombin generation, standard coagulation times, markers of endothelial activation, plasma levels of coagulation factors and copeptin, and hematocrit. Results: Orthostatic challenge caused a significant endothelial and coagulation activation in patients (Group 1) and healthy controls (Group 2): Plasma levels of prothrombin fragment F1+2 were increased by approximately 35% and thrombin/antithrombin-complex (TAT) increased 5-fold. Several coagulation variables were significantly altered in Group 1 but not in Group 2: Coagulation times (CTs) were significantly shortened and alpha angles, peak rate of thrombin generation (VELINDEX), tissue factor (TF) and copeptin plasma levels were significantly increased (comparison between standing and baseline). Moreover, the shortening of CTs and the rise of copeptin plasma levels were significantly higher in Group 1 vs. Group 2 (comparison between groups). Conclusion: The coagulation system of patients with a history of ischemic stroke can be more easily shifted toward a hypercoagulable state than that of healthy controls. Attentive and long-term anticoagulant treatment is essential to keep patients from recurrence of vascular events.

Copeptin Predicts Mortality in Critically Ill Patients

Background

Critically ill patients admitted to a medical intensive care unit exhibit a high mortality rate irrespective of the cause of admission. Besides its role in fluid and electrolyte balance, vasopressin has been described as a stress hormone. Copeptin, the C-terminal portion of provasopressin mirrors vasopressin levels and has been described as a reliable biomarker for the individual’s stress level and was associated with outcome in various disease entities. The aim of this study was to analyze whether circulating levels of copeptin at ICU admission are associated with 30-day mortality.

Methods

In this single-center prospective observational study including 225 consecutive patients admitted to a tertiary medical ICU at a university hospital, blood was taken at ICU admission and copeptin levels were measured using a commercially available automated sandwich immunofluorescent assay.

Results

Median acute physiology and chronic health evaluation II score was 20 and 30-day mortality was 25%. Median copeptin admission levels were significantly higher in non-survivors as compared with survivors (77.6 IQR 30.7–179.3 pmol/L versus 45.6 IQR 19.6–109.6 pmol/L; p = 0.025). Patients with serum levels of copeptin in the third tertile at admission had a 2.4-fold (95% CI 1.2–4.6; p = 0.01) increased mortality risk as compared to patients in the first tertile. When analyzing patients according to cause of admission, copeptin was only predictive of 30-day mortality in patients admitted due to medical causes as opposed to those admitted after cardiac surgery, as medical patients with levels of copeptin in the highest tertile had a 3.3-fold (95% CI 1.66.8, p = 0.002) risk of dying independent from APACHE II score, primary diagnosis, vasopressor use and need for mechanical ventilation.

Conclusion

Circulating levels of copeptin at ICU admission independently predict 30-day mortality in patients admitted to a medical ICU.

Postischemic Inflammation in Acute Stroke

Cerebral ischemia is caused by arterial occlusion due to a thrombus or an embolus. Such occlusion induces multiple and concomitant pathophysiological processes that involve bioenergetic failure, acidosis, loss of cell homeostasis, excitotoxicity, and disruption of the blood-brain barrier. All of these mechanisms contribute to neuronal death, mainly via apoptosis or necrosis. The immune system is involved in this process in the early phases after brain injury, which contributes to potential enlargement of the infarct size and involves the penumbra area. Whereas inflammation and the immune system both exert deleterious effects, they also contribute to brain protection by stimulating a preconditioning status and to the concomitant repair of the injured parenchyma. This review describes the main phases of the inflammatory process occurring after arterial cerebral occlusion, with an emphasis on the role of single mediators.

Copeptin, resistant hypertension and renal sympathetic denervation

BACKGROUND

Renal denervation is used as a treatment option for patients with resistant hypertension. But only a subgroup of patients benefits from renal sympathetic denervation (RDN). Biomarkers might be helpful to identify patients who respond to RDN. Copeptin as a surrogate for vasopressin levels is increased in hypertension and other cardiovascular diseases. This study aims to evaluate the effect of RDN on Copeptin and its prognostic value for response to RDN.

METHOD AND RESULTS

A total of 40 patients have been included in the study. The responder rate was 47.5% on 24 h ambulatory blood pressure measurements. The mean systolic 24 h blood pressure dropped from 152 ± 10 mmHg to 147 ± 17 mmHg (p = .044) in the six month follow up. The mean baseline level of Copeptin was 7.4 pmol/l (interquartile range 3.7-11.6) for responders and 8.4 pmol/l (interquartile range 5.7-11-8) for non-responders (p = .53). The Copeptin levels did not change over time after renal denervation.

CONCLUSION

Baseline measurements of Copeptin in patients undergoing RDN for resistant hypertension have no predictive value for response to RDN. Despite lowering the blood pressure RDN has no influence on Copeptin levels in this short time follow up period.

Plasma copeptin and functional outcome in patients with ischemic stroke and type 2 diabetes

BACKGROUND

The activation of the arginine vasopressin system may be involved in the pathology of stroke and diabetes. In this study, we therefore evaluated the short-term prognostic value of early measurement of plasma copeptin levels in Chinese patients with type 2 diabetes mellitus (T2DM) and acute ischemic stroke (AIS).

METHODS

From July 2014 to June 2015, all T2DM patients with first-ever AIS were included. Plasma levels of copeptin were tested at admission. The prognostic value of copeptin to predict the functional outcome and mortality 3months after stroke was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors.

RESULTS

We recorded 247 stroke patients with T2DM. The copeptin levels were obtained in those patients with a median value of 14.3pmol/L (IQR, 9.5-17.1pmol/L). At 3-month follow-up, a favorable functional outcome was found in 86 patients (34.8%). Plasma copeptin levels in patients with an unfavorable outcome were significantly greater than those in patients with a favorable outcome (16.2 [IQR, 12.2-20.3] vs. 12.4 [IQR, 8.6-15.2] pmol/L; Z=5.399; P<0.0001). In univariate logistic regression analysis, with an unadjusted OR of 1.123 (95% CI, 1.072-1.177, P<0.001), copeptin had a strong association with unfavorable functional outcome. In multivariate analyses, a copeptin level in the highest inter-quartile (>17.1pmol/L) was associated with a higher risk of unfavorable functional outcome (OR=4.62; 95% CI=2.63-9.21; P<0.001). After adjusting for other outcome predictors, a copeptin level in the highest inter-quartile (>17.1pmol/L) was associated with a higher risk of mortality (OR=5.12; 95% CI=2.20-11.38; P<0.001).

CONCLUSION

Our study suggested that copeptin levels may reliably predict short-term stroke prognosis at its onset in Chinese patients with T2DM and stroke.

Serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population

PURPOSE

The aim of this study was to investigate copeptin levels in serum, and assess their associations with type 2 diabetes (T2DM) and diabetic complications.

METHODS

In this post hoc analysis, serum levels of copeptin were tested in 306 patients with T2DM. Clinical information including diabetic retinopathy (DR) and diabetic nephropathy (DN) were collected. The relation of serum copeptin with DR and DN were investigated with the use of logistic regression models according to equal quartiles of the distributions of serum copeptin.

RESULTS

We found that serum copeptin levels were significantly higher in diabetes as compared to normal controls [9.4(IQR, 7.4-12.5) pmol/L vs. 4.1(IQR, 2.5-6.2) pmol/L; P<0.0001]. In multivariate analysis, there was an increased risk of T2DM associated with copeptin levels (OR 1.312, 95% CI: 1.204-1.403; P<0.0001) after adjusting for possible confounders. After adjustment for possible confounders, serum copeptin levels were positively associated with the DR (odds ratio [OR], 1.117; 95% confidence interval [CI], 1.072-1.241; P<0.001) and DN (OR, 1.259; 95% CI, 1.198-1.323; P<0.001). Compared with the first quartile of serum copeptin levels, the ORs for DR and DN were as follows: second quartile, 1.19 (95% CI, 0.94-1.51, P=0.12) and 1.37 (95% CI, 0.78-2.37, P=0.28); third quartile, 1.61 (95% CI, 1.18-2.43, P=0.005) and 2.12 (95% CI, 1.32-3.27, P=0.003); fourth quartile, 2.83 (95% CI, 2.04-4.93; P<0.001) and 3.48 (95% CI, 1.77-7.03; P<0.001), respectively.

CONCLUSIONS

Using a post-hoc analysis our data show that elevated serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population, suggesting a potential role of the AVP system (copeptin) in the pathophysiology of diabetes.