Plasma Copeptin Research Articles

Peripheral Insulin Resistance Is Associated with Copeptin in Patients with Chronic Kidney Disease.

Insulin resistance is associated with cardiovascular disease risk and worsened kidney function. Patients with CKD have higher levels of insulin resistance. Elevated levels of copeptin (a surrogate for vasopressin levels) have been associated with an increased incidence and progression of CKD, and with incident diabetes mellitus. The purpose of our study was to examine the relationship between insulin resistance, copeptin, and CKD. We performed a cross-sectional study to investigate if insulin resistance was associated with higher copeptin levels in nondiabetic patients with stage 3-4 CKD versus controls. We measured plasma copeptin levels and used data from 52 patients with stage 3-4 CKD and 85 controls (eGFR ≥60 ml/min per 1.73 m2) enrolled in the Insulin Resistance in Chronic Kidney Disease (IRCKD) study. We then used a multivariable linear-regression model to assess the independent relationship between peripheral or hepatic insulin resistance and copeptin across levels of eGFR. We found that in patients with CKD (eGFR of 30-60 ml/min per 1.73 m2), but not in controls, peripheral insulin resistance was significantly correlated with higher levels of log copeptin (r=-0.21, P=0.04). In patients with CKD, when adjusted for age, sex, BMI, serum osmolality, log IL6, and log leptin/adiponectin ratio, each 1 SD decrease in insulin sensitivity was associated with a 39% increase in serum copeptin levels. The relationship between hepatic insulin resistance, copeptin, and eGFR is similar between controls and patients with reduced eGFR. Peripheral insulin resistance is associated with elevated copeptin levels in nondiabetic patients with stage 3-4 CKD. Further research into how the interaction between peripheral insulin resistance and elevated vasopressin affects CKD progression could be of interest.

Copeptin and insulin-like growth factor-1 predict long-term outcomes after aneurysmal subarachnoid hemorrhage: A large prospective cohort study

ObjectiveThe predictive roles of copeptin and insulin-like growth factor-1 (IGF-1) in aneurysmal subarachnoid hemorrhage (aSAH) remain controversial. We aimed to define the relationship between copeptin and IGF-1 levels and functional outcome as well as quality of life (QoL) after aSAH. MethodsPatients with aSAH were prospectively enrolled in a tertiary university hospital. Controls were sex- and age-matched healthy subjects. Plasma concentrations of copeptin and IGF-1 were measured on admission. Demographics and clinical, radiological and laboratory characteristics of the patients were collected. Favorable functional outcome was defined as modified Rankins≤2, and QoL was evaluated by the 36-Item Short Form Health Survey (SF-36) 1 year after aSAH. Uni- and multivariable analyses were performed. ResultsOne hundred eighteen patients were eligible, with 122 healthy controls were included in this study. Plasma copeptin levels were significantly higher and plasma IGF-1 was lower in patients than in controls. Both copeptin (adjusted HR 4.143 [1.120–15.328], p = 0.033) and IGF-1 levels (adjusted HR 0.089 [0.013–0.602], p = 0.013) were positively associated with 1-year mortality, while only single copeptin and IGF-1 concentrations were independent predictors of poor functional outcome and QoL, respectively. ConclusionsPlasma copeptin and IGF-1 levels are abnormal in patients with acute aSAH, and this may reliably predict long-term mortality, functional outcome and QoL.

MO021ENHANCED MCP-1 RELEASE IN EARLY AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Abstract Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in either the PKD1 or PKD2 gene. While kidney failure typically occurs in adulthood, the disease starts in utero. The best change of preserving renal function long term might be the use of agents with few side effects as early as possible. For this approach, both better early prognostic stratification and novel treatment options are needed. The pediatric phase of ADPKD, while kidney function is still normal and before significant tissue destruction has occurred could be the best stage both to identify and study prognostic biomarkers as well as to identify novel targets for early treatment. Copeptin (a surrogate for vasopressin), epidermal growth factor (EGF) ( a measure for functional tubular mass) and monocyte chemoattractant protein-1 (MCP-1) ( a chemoattractant for macrophages) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models. Method A monocentric cross-sectional study in a tertiary referral center was performed. All consenting genotyped ADPKD patients attending the outpatient pediatric ADPKD clinic of the university hospital of Leuven and age, sex and BMI matched healthy controls were included between June and October 2017. Plasma copeptin, urinary EGF and urinary MCP-1 were evaluated. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells and fetal kidney tissue. Results 53 genotyped ADPKD patients and 53 controls were included. Mean (SD) age was 10.4 (5.9) vs 10.5 (6.1) years (P=0.543), and eGFR 122.7 (39.8) vs 114.5 (23.1) ml/min/1.73 m2 (P= 0.177) in patients vs controls respectively. Outcome parameters in table. Plasma copeptin and EGF secretion were comparable between both groups. Median (IQR) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 (213.8)) compared to controls (154.7 (98.0)) (P= 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion triggered by fetal bovine serum. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration. Conclusion An increase in tubular MCP-1 secretion is an early event in ADPKD, long before kidney function decline and in children with few kidney cysts. MCP-1 is a promising early disease severity marker and a potential treatment target.

The differential activation of cardiovascular hormones across distinct stages of portal hypertension predicts clinical outcomes

Background and aimsThe cardiovascular hormones renin/angiotensin/aldosterone (RAA), brain-type natriuretic peptide (BNP)and arginine-vasopressin (AVP) are key regulators of systemic circulatory homeostasis in portal hypertension (PH). We assessed (i) the activation of renin, BNP and AVP across distinct stages of PH and (ii) whether activation of these hormones correlates with clinical outcomes.MethodsPlasma levels of renin, proBNP and copeptin (AVP biomarker) were determined in 663 patients with advanced chronic liver disease (ACLD) undergoing hepatic venous pressure gradient (HVPG) measurement at the Vienna General Hospital between 11/2011 and 02/2019. We stratified for Child stage (A–C), HVPG (6–9 mmHg, 10–15 mmHg, ≥ 16 mmHg) and compensated vs. decompensated ACLD.ResultsWith increasing PH, hyperdynamic state was indicated by higher heart rates (6–9 mmHg: median 71.0 [IQR 18.0] bpm, 10–15 mmHg: 76.0 [19.0] bpm, ≥ 16 mmHg: 80.0 [22.0] bpm; p < 0.001), lower mean arterial pressure (6–9 mmHg: 103.0 [13.5] mmHg, 10–15 mmHg: 101.0 [19.5] mmHg, ≥ 16 mmHg: 99.0 [21.0] mmHg; p = 0.032) and lower serum sodium (6–9 mmHg: 139.0 [3.0] mmol/L, 10–15 mmHg: 138.0 [4.0] mmol/L, ≥ 16 mmHg: 138.0 [5.0] mmol/L; p < 0.001). Across HVPG strata (6–9 mmHg vs. 10–15 mmHg vs ≥ 16 mmHg), median plasma levels of renin (21.0 [50.5] vs. 25.1 [70.9] vs. 65.4 [219.6] µIU/mL; p < 0.001), proBNP (86.1 [134.0] vs. 63.6 [118.0], vs. 132.2 [208.9] pg/mL; p = 0.002) and copeptin (7.8 [7.7] vs. 5.6 [8.0] vs. 10.7 [18.6] pmol/L; p = 0.024) increased with severity of PH. Elevated renin levels independently predicted first hepatic decompensation (adjusted hazard ratio [aHR]: 1.69; 95% confidence interval [95% CI] 1.07–2.68; p = 0.025) and mortality in compensated patients (aHR: 3.15; 95% CI 1.70–5.84; p < 0.001) and the overall cohort aHR: 1.42; 95% CI 1.01–2.01; p = 0.046). Elevated copeptin levels predicted mortality in decompensated patients (aHR: 5.77; 95% CI 1.27–26.33; p = 0.024) and in the overall cohort (aHR: 3.29; 95% CI 1.36–7.95; p = 0.008). ProBNP levels did not predict clinical outcomes.ConclusionsThe cardiovascular hormones renin, proBNP and AVP are activated with progression of ACLD and PH. Renin activation is a risk factor for hepatic decompensation and mortality, especially in compensated patients. Increased plasma copeptin is a risk factor for mortality, in particular in decompensated patients.

Copeptin Levels Before and After Transsphenoidal Surgery for Cushing Disease: A Potential Marker of Remission

Abstract Objectives: Chronic hypercortisolemia suppresses AVP secretion. Copeptin makes up the C-terminal portion of the AVP precursor pre-pro-AVP, is released in stoichiometric amounts with AVP, and is a stable surrogate marker of AVP.A post-operative increase in plasma copeptin was hypothesized to be a marker of remission of Cushing Disease (CD). Methods: Plasma copeptin was obtained in patients with CD before and daily in the first week after transsphenoidal surgery (TSS), measured using the Brahm Kryptor Compact PLUS sandwich immunofluorescent assay. Urine output, serum sodium, urine specific gravity, and urine/serum osmolality were used to determine development of central diabetes insipidus (DI) and/or syndrome of inappropriate anti-diuretic hormone secretion (SIADH). Change in copeptin reflects pre-TSS to peak post-TSS copeptin levels. Statistical analyses were completed using non-parametric tests. Results are presented as median (inter-quartile range). Results: Forty-four patients (64% female, 7-55 years old) were included. After TSS, 8 (18%) developed DI, 13 (30%) developed SIADH, 4 (9%) developed both DI and SIADH, and 19 (43%) developed neither. Thirty-three patients had a follow-up at 3-6 months. Overall, there was no difference in peak post-TSS copeptin for patients in remission versus those not in remission [6.1 pmol/L (4.3-12.1) vs. 7.3 pmol/L (5.4-8.4), p=0.88]. There was, also, no difference in the copeptin change for those in remission versus not in remission [2.3 pmol/L (-0.5-8.2) vs. 0.1 pmol/L (-0.1-2.2), p=0.46]. When we excluded patients who developed a water balance disorder postoperatively, there was a difference in peak post-TSS copeptin for those in remission [10.2 pmol/L (6.9-21.0)] vs. those not in remission [5.4 pmol/L (4.6-7.3), p=0.032], but not in the change in copeptin for those in remission vs. not in remission [5.1 pmol/L (0.3-19.5) vs. 1.1 pmol/L (-0.1-2.2), p=0.39]. Conclusions: Post-TSS plasma copeptin may be a useful early marker to predict remission of CD after TSS. However, the utility of this test may be limited to those who do not develop water balance disorders post-operatively. Additional studies with larger sample sizes are needed to confirm these findings and to determine a post-operative plasma copeptin cutoff level that may predict remission of CD.

Role of A1/A2 Neurons in the Dysregulation of Vasopressin Release and Dilutional Hyponatremia in Liver Disease

Purpose Inappropriate release of arginine vasopressin (AVP) has been linked to dilutional hyponatremia in patients with liver disease. Plasma AVP remains elevated leading to water retention, hypoosmolality, ascites formation, and a perceived decrease in plasma volume. The perceived decrease in plasma volume is sensed by the A1/A2 norepinephrine neurons in the caudal ventrolateral medulla (CVLM) and the nucleus tractus solitarius (NTS) respectively. We propose that these neurons provide the initial stimuli that activates AVP-secreting neurons in the supraoptic nucleus (SON) leading to increased plasma AVP and dilutional hyponatremia. Method We used the Bile duct ligation (BDL) rat model of liver failure for our experiments. Selective lesioning of the SON-projecting A1/A2 norepinephrine neurons was achieved using anti-DβH-Saporin [IT-03] (Advanced Targeting Systems). Plasma copeptin concentration was measured as a surrogate marker for plasma AVP using ELISA. Plasma osmolality and hematocrit measurements were also taken. Immunohistochemistry for delta fosB and dopamine beta-hydroxylase (DβH) was performed on brain tissue slices. The slices were viewed using an Olympus microscope (BX41) equipped for epifluorescence and images were taken using Olympus DP70 digital camera with DP manager software (version 2.2.1). The number of immunoreactive cells to ΔFosB and DβH were counted using Image J. Results We found that lesioning of the A1/A2 neurons in the Saporin/BDL group (n=9) caused a decrease in the plasma AVP concentration versus the Vehicle/BDL control group (n=6), p<0.05. However, the number of delta fosB immunoreactive A1/A2 cells was not significantly different. Lesioning of the A1/A2 neurons seemed to normalize osmolality and hematocrit in the BDL group. Although the difference was not statistically significant. Conclusion Our experiments suggests that A1/A2 neurons could be involved in the increased plasma AVP seen in male BDL rats as well as the decreased plasma osmolality.

Hypertension due to loss of water

In the current issue of Acta Physiologica, two papers are published investigating the development of arterial hypertension under conditions of pathological loss of free water in two disease models. Kovaric et al 1 studied rats with chronic renal failure, shedding excessive free water via their remnant kidney due to a hypostenuric concentrating defect. Wild et al. 2 investigated a transgenic mouse model for psoriasis, losing free water via the psoriatic skin lesions. In both cases the animals displayed hypertension, cutaneous vasoconstriction, and metabolic adaptations towards enhanced production of urea and organic osmolytes typical for a phylogenetically ancient water conservation response termed aestivation 3 . The international consortia of investigators spearheaded by Titze, Karbach, and Kitada therefore conclude that in both cases the hypertension was due to cutaneous vasoconstriction in an attempt to limit epidermal water loss. Because in either case the hypertension was associated with loss of water, and thus with hypo- rather than hypervolemia, the authors argue, that this concept of pathogenesis of hypertension is antipodal to the classic view that relies on hypervolemia due to sodium retention.

Enhanced MCP-1 Release in Early Autosomal Dominant Polycystic Kidney Disease

IntroductionAutosomal dominant polycystic kidney disease (ADPKD) causes kidney failure typically in adulthood, but the disease starts in utero. Copeptin, epidermal growth factor (EGF), and monocyte chemoattractant protein-1 (MCP-1) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models.MethodsIn a cross-sectional study, plasma copeptin, urinary EGF, and urinary MCP-1 were evaluated in a pediatric ADPKD cohort and compared with age-, sex-, and body mass index (BMI)-matched healthy controls. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells, and fetal kidney tissue.ResultsFifty-three genotyped ADPKD patients and 53 controls were included. The mean (SD) age was 10.4 (5.9) versus 10.5 (6.1) years (P = 0.543), and the estimated glomerular filtration rate (eGFR) was 122.7 (39.8) versus 114.5 (23.1) ml/min per 1.73 m2 (P = 0.177) in patients versus controls, respectively. Plasma copeptin and EGF secretion were comparable between groups. The median (interquartile range) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 [213.8]) compared with controls (154.7 [98.0], P = 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration.ConclusionAn increase in tubular MCP-1 secretion is an early event in ADPKD. MCP-1 is an early disease severity marker and a potential treatment target.

Plasma copeptin levels in children with pulmonary arterial hypertension associated with congenital heart disease

The study aimed to evaluate the plasma copeptin levels in children with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD), to assess the predictive value of plasma copeptin level for adverse outcomes, and to correlate its levels with various data in these patients. We included 25 children with PAH-CHD as group I and 25 children with CHD and no PAH as group II. Twenty-five healthy children of matched age and sex served as the control group. Patients were evaluated by echocardiography and right heart catheterization. The plasma level of copeptin was also measured. All patients were followed up for death or readmission for 1 year. Plasma copeptin levels were significantly higher in group I compared to group II and the control group and were correlated with increasing severity of PAH. The best cutoff of plasma copeptin level to predict poor prognosis in group I was ≥24.2 ng/ml with a sensitivity of 90% and a specificity of 80%. There was a statistically significant positive correlation between plasma copeptin levels and mean pulmonary pressure, pulmonary vascular resistance, and pulmonary blood flow, while there was a statistically significant negative correlation between plasma copeptin levels and right ventricular diastolic function.Conclusion: Plasma copeptin levels are elevated in children with PAH-CHD and found to be a good predictive marker for the severity of PAH and poor prognosis in these children. What is Known: •PH is a life-threatening condition that can lead to right ventricular failure and death. •We need a non-invasive easy biomarker that can identify PH children with unfavorable prognosis who needed further intervention. What is New: •It is the first study that assessed the prognostic value of plasma copeptin levels in children with PAH-CHD. •We found that copeptin is an accurate dependable biomarker for predicting poor outcomes in children with PAH-CHD who needed extensive furtherintervention.

The Role of Consecutive Plasma Copeptin Levels in the Screening of Delayed Cerebral Ischemia in Poor-Grade Subarachnoid Hemorrhage.

The prognostic value of copeptin in subarachnoid hemorrhage (SAH) has been reported, but the prognosis was largely affected by the initial clinical severity. Thus, the previous studies are not very useful in predicting delayed cerebral ischemia (DCI) in poor-grade SAH patients. Here, we first investigated the feasibility of predicting DCI in poor-grade SAH based on consecutive measurements of plasma copeptin. We measured copeptin levels of 86 patients on days 1, 3, 5, 7, 9, 11, and 13 using ELISA. The primary outcome was the association between consecutive copeptin levels and DCI development. The secondary outcomes were comparison of copeptin with C-reactive protein (CRP) in predicting DCI. Additionally, we compared the prognostic value of transcranial Doppler ultrasonography (TCD) with copeptin using TCD alone to predict DCI. Increased copeptin (OR = 1.022, 95% CI: 1.008–1.037) and modified Fisher scale IV (OR = 2.841; 95% CI: 0.998–8.084) were closely related to DCI. Consecutive plasma copeptin measurements showed significant differences between DCI and non-DCI groups (p < 0.001). Higher CRP and DCI appeared to show a correlation, but it was not statistically significant. Analysis of copeptin changes with TCD appeared to predict DCI better than TCD alone with AUCROC differences of 0.072. Consecutive measurements of plasma copeptin levels facilitate the screening of DCI in poor-grade SAH patients.

Copeptin is increased by nausea and vomiting during hypertonic saline infusion in healthy individuals.

Measurement of hypertonic saline-stimulated copeptin has recently been described for the differentiation of polyuria-polydipsia syndrome. This study aims to determine the copeptin response to intravenous 3% hypertonic saline, including evaluation of adverse effects, in a local cohort of healthy adults >18years in Australia. Prospective clinical study. Twenty healthy volunteers (10 males and 10 females) were recruited. Participants underwent infusion of 3% hypertonic saline via a previously described standardized protocol, until the plasma sodium was ≥150mmol/L, with measurement of plasma copeptin. Mean peak sodium was 152mmol/L±SD 1.4 with osmolality 315mmol/kg±SD 3.9. Median volume of hypertonic saline infused to reach target sodium≥150mmol/L was 1536mL (IQR 1362, 1992). Mean rate of plasma sodium rise was 5.9mmol/L/hour±SD 1.5. Hypertonic saline-stimulated copeptin had non-parametrical distribution with median of 33.8pmol/L (IQR 27.6, 63.6). Overall median symptom burden was 6/10 (range 3/10-9/10). Copeptin was significantly higher for those who experienced nausea and/or vomiting (n=13) (median 39.0pmol/L; IQR 32.5, 90), compared to those participants who did not experience either (median 20.0pmol/L; IQR 13.0, 31.0) (P=0.003). There were no serious adverse events. Hypertonic saline-stimulated copeptin measurements were similar in our population compared with previously reported reference intervals in healthy volunteers. There is a wide range of stimulated copeptin measurements in the healthy population. Nausea and vomiting are common adverse effects which enhance the copeptin response.

Improving Neonatal and Maternal Outcome by Inducing Mild Labor before Elective Cesarean Section: The Lacarus Randomized Controlled Trial

Background: Newborns delivered by elective cesarean section (CS) are at higher respiratory risk than those delivered vaginally or by CS proceeded by labor (secondary CS). The oxytocin challenge test (OCT) induces uterine contractions that trigger the release of fetal hormones regulating lung fluid clearance during transition from the uterine to an air-breathing environment. Objectives: The aim is to summarize current evidence and outline the Lacarus trial protocol. Methods: Literature review informed the design of a randomized placebo-controlled multicenter trial of OCT preceding elective CS in 1,450 women with a singleton pregnancy due for CS at >35 weeks gestation, without preceding contractions, rupture of the membranes, or antenatal steroids. OCT comprises the infusion of oxytocin 5 IU/500 mL Ringer lactate at a rate of 12 mL/h, doubling every 10 min until inducing 5 uterine contractions per 15-min interval. The primary endpoint is the occurrence of neonatal respiratory morbidity within 24 h after birth. Secondary endpoints include biochemical and physiological parameters of fetal and maternal well-being, such as breastfeeding rate and fetal plasma copeptin concentrations. Conclusion: This is the first trial to test the hypothesis that oxytocin-induced contractions before elective CS is a promising application of physiologic principles gleaned from natural birth to improve neonatal and maternal outcomes.

The diagnosis and prognostic value of plasma copeptin in traumatic brain injury: a systematic review and meta-analysis

The purpose of this meta-analysis was to assess the diagnosis and prognostic value of plasma copeptin levels after traumatic brain injury (TBI). The databases PubMed, Cochrane Library, OvidSP, Google Scholar, VIP, CNKI, and WFSD were systematically searched from the inception dates to May 9, 2020. The pooled analysis of relevant data was conducted by the RevMan 5.3 software. Subgroups analysis was performed to explore the impact of age, country, male ratio, follow-up time, and Glasgow coma score (GCS) on the pooled area under curve (AUC) values of assessment mortality. A total of 17 studies involving 2654 participants were included in the current meta-analysis. The pooled results demonstrated that increased plasma copeptin levels were significantly associated with TBI [SMD, 2.44; 95%CI, 1.59 ~ 3.29; P < 0.00001] and also were significantly associated with mortality [SMD, 1.37; 95%CI, 1.16 ~ 1.58; P < 0.00001], and poor functional outcomes (PFO) [SMD, 1.44; 95%CI, 1.20 ~ 1.68; P < 0.00001] in patients with TBI. Furthermore, the copeptin had a significant value in diagnosing brain concussion [AUC, 0.90; 95%CI, 0.84 ~ 0.95; P < 0.00001] and predicting progressive hemorrhagic injury [AUC, 0.83; 95%CI, 0.80 ~ 0.87; P < 0.00001], acute traumatic coagulopathy [AUC, 0.84; 95%CI, 0.79 ~ 0.89; P < 0.00001], mortality [AUC, 0.89; 95%CI, 0.87 ~ 0.92; P < 0.00001], and PFO [AUC, 0.88; 95%CI, 0.84 ~ 0.92; P < 0.00001] in patients with TBI. The subgroup analysis findings suggested that the age, country, male ratio, follow-up time, and GCS were not obvious factors influencing the pooled AUC values of assessment mortality. The authors indicate that the plasma copeptin is a potentially promising biomarker for TBI diagnosis and prognosis prediction.

Hydration Biomarkers Are Related to the Differential Abundance of Fecal Microbiota and Plasma Lipopolysaccharide-Binding Protein in Adults

Introduction: Prevalence of chronic hypohydration remains elevated among adults in the USA; however, the health effects of hypohydration in regards to human gut health have not been explored. Methods: This study examined the relationship between total water intake, hydration biomarkers (first-morning urine specific gravity [FMU_sg], first-morning urine volume [FMU_vol], and plasma copeptin), fecal microbiota, and plasma lipopolysaccharide-binding protein (LBP) in adults (25–45 years, 64% female). Fecal microbiota composition was assessed using 16S rRNA gene sequencing (V4 region). Immunoassays quantified plasma copeptin and LBP in fasted venous blood samples. Dietary variables were measured using 7-day food records. Linear discriminant analysis effect size (LEfSe) analyzed differentially abundant microbiota based on median cutoffs for hydration markers. Multiple linear regressions examined the relationship between LBP and copeptin. Results: LEfSe identified 6 common taxa at the genus or species level that were differentially abundant in FMU_sg, total water (g/day), or plasma copeptin (µg/mL) groups when split by their median values. Uncultured species in the Bacteroides, Desulfovibrio, Roseburia, Peptococcus, and Akkermansia genera were more abundant in groups that might indicate poorer hydration status. Multivariate linear analyses revealed a positive relationship between plasma copeptin and LBP when controlling confounding variables (F(6,52) = 4.45, p = 0.002, R² = 0.34). Conclusions: Taxa common between markers are associated with the intestinal mucus layer, which suggests a potential link between hydration status and intestinal mucus homeostasis. The relationship between LBP and copeptin indicates that copeptin may be sensitive to metabolic endotoxemia and potentially gut barrier function.

Evaluation of copeptin and psychological stress among healthcare providers during COVID-19 pandemic

ABSTRACT Background: The COVID-19 pandemic created a remarkable impact on healthcare providers (HCP) both physically and psychologically. Perceived psychological stress (PSS) influences the homeostatic equilibrium, involving activation of the sympathetic nervous system and hypothalamus pituitary adrenal (HPA) axis. Copeptin, C-terminal portion of Vasopressin (AVP) precursor is stable; however, evidence about impact of PSS on copeptin levels is limited. Aim: The aim of this study was to estimate the influence of psychological stress on copeptin levels among HCP working in intensive care unit (ICU). Methods: A total of 70 HCP served in quarantine ICU participated in this prospective study; 35 physicians (28 males and 7 females) and 35 nurses (10 males and 25 females). A control group of 40 HCP matched age, BMI and specialty in non- quarantine hospitals. Fasting morning blood samples were withdrawn for determination of copeptin, cortisol, insulin at three points; pre-quarantine at ICU. Second point at end of first week and third point was two weeks’ post quarantine. A questionnaire was conducted to all participants to assess stress (PSS). Cortisol was determined by a chemiluminescence immunoassay while insulin and Copeptin were measured by ELISA. Results: Baseline plasma copeptin level pre-quarantine was significantly increased 15.76 ± 8.6 pmol/l (P = 0.001*) and was positively correlated with high stress PSS score mean 66.9 ± 18.3. Post-quarantine copeptin was markedly reduced 3.98 ± 1.28 pmol/l and mean PSS was 23.0 ± 7.95 (P = 0.001*). Also, there was positive correlation between plasma copeptin and PSS, systolic blood pressure and serum insulin. On the other hand, there was no correlation between copeptin and serum cortisol. Conclusion: Our finding suggested that copeptin may be used a potential biomarker for physiological strain during work in a stressful environment.

The Emerging Role of Copeptin.

Direct measurement of the nonapeptide vasopressin has been limited by analyte instability ex vivo and in vivo rapid degradation, low serum concentrations requiring a sensitive assay and inherent secretory pulsatility. Copeptin is a 39 amino acid glycopeptide cleavage product of vasopressin synthesis with high stability, providing a marker of vasopressin secretion. Copeptin measurement has applications in diagnosis of diabetes insipidus and other diseases with altered vasopressin secretion. This review summarises our current understanding of serum copeptin measurement in diabetes insipidus and possible future applications of copeptin assays. As vasopressin is a stress hormone, there is emerging evidence on the use of copeptin for diagnosis and prognostication of disorders such as syndrome of inappropriate anti-diuretic hormone secretion, diabetes mellitus, critical illness, stroke, cardiovascular disease, respiratory disease, renal disease and thermal stress. Copeptin concentration measurement is likely to improve the diagnostic reliability of diabetes insipidus and, as a marker of stress, may have diagnostic or prognostic utility in specific clinical circumstances. Further studies are needed to determine if goal-directed therapy using plasma copeptin concentrations may improve patient outcomes.

Copeptin and renal function decline, cardiovascular events and mortality in type 1 diabetes.

Plasma copeptin is a surrogate of arginine vasopressin (AVP) secretion and is associated with a risk of renal and cardiovascular disease. We investigated associations between copeptin and renal events, cardiovascular events and mortality in type 1 diabetes (T1D). We conducted a prospective cohort study on 658 individuals with T1D from Steno Diabetes Center Copenhagen. Plasma copeptin concentrations and conventional risk factors were assessed at baseline. The five endpoints were traced through national registries and electronic laboratory records. Baseline mean age was 55 ± 13 years and estimated glomerular filtration rate (eGFR) was 81 ± 26 mL/min/1.73 m2. The median follow-up was 6.2 years (interquartile range 5.8-6.7); 123 participants reached a combined renal endpoint [decline in eGFR ≥30%, end-stage kidney disease (ESKD) or all-cause mortality], 93 had a decrease in eGFR ≥30%, 21 developed ESKD, 94 experienced a combined cardiovascular endpoint and 58 died from all causes. Higher copeptin was associated with all endpoints in unadjusted Cox regression analyses. Upon adjustment for baseline eGFR, the associations were attenuated and remained significant only for the combined renal endpoint and decrease in eGFR ≥30%. Results were similar upon further adjustment for other risk factors, after which hazard ratios for the two renal endpoints were 2.27 (95% confidence interval 1.08-4.74) and 4.49 (1.77-11.4), respectively, for the highest versus the lowest quartile of copeptin. Higher copeptin was an independent risk marker for a combined renal endpoint and decline in renal function. AVP may be a marker of renal damage or a factor whose contribution to renal and cardiovascular risk is partially mediated by renal damage.

Predictive value of plasma copeptin level for diagnosis and mortality of pulmonary embolism

Early diagnosis and risk stratification may provide a better prognosis in pulmonary embolism (PE). Copeptin has emerged as a valuable predictive biomarker in various cardiovascular diseases. The aim of this study was to determine the levels of copeptin in patients with acute PE and to evaluate its relationship with disease severity and PE-related death. Fifty-four patients and 60 healthy individuals were included in this study. Copeptin concentrations and right ventricular dysfunction were analyzed. The correlation between copeptin levels and hemodynamic and echocardiographic parameters was examined. After these first measurements, patients were evaluated with PE-related mortality at the one-year follow-up. The copeptin levels were higher in PE patients than in the control group (8.3 ng/mL vs 3.8 ng/mL, p<0.001). Copeptin levels were found to be significantly higher in patients with PE-related death and right ventricular dysfunction (10.2 vs 7.5 ng/ml, p=0.001; 10.5 vs 7.5 ng/ml, p=0.002, respectively). When the cut-off value of copeptin was ≥5.85, its sensitivity and specificity for predicting PE were 71.9% and 85.0%, respectively (AUC=0.762, 95% CI=0.635-0.889, p<0.001). The copeptin measurement had moderate sensitivity and specificity in predicting the diagnosis of PE, and the copeptin level was significantly higher in patients with PE-related death at the one-year follow-up. Copeptin may be a useful new biomarker in predicting diagnosis, risk stratification, and prognosis of PE.

Vasopressin associated with renal vascular resistance in adults with longstanding type 1 diabetes with and without diabetic kidney disease.

Arginine vasopressin (AVP) and its surrogate, copeptin, have been implicated in diabetic kidney disease (DKD) pathogenesis, which develops in a subset of people with longstanding type 1 diabetes, but not in others (DKD Resistors). We hypothesized that patients with DKD would exhibit higher copeptin concentrations vs. DKD Resistors. Participants with type 1 diabetes (n = 62, duration ≥50 years) were stratified into 42 DKD Resistors and 20 with DKD (eGFR ≤60 mL/min/1.73m2 or ≥30 mg/day urine albumin), and age/sex-matched controls (HC, n = 74) were included. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were calculated by inulin and p-aminohippurate clearance before and after angiotensin II (ang II) infusion. Renal vascular resistance (RVR) was calculated as mean arterial pressure/renal blood flow. Plasma copeptin, renin, aldosterone, neutrophil gelatinase-associated lipocalin (NGAL), and urea concentrations were measured, along with 24-h urine volume. DKD resistors had lower copeptin (95% CI: 4.0 [3.4-4.8] pmol/l) compared to DKD (5.8 [4.5-7.6] pmol/l, p = 0.02) and HC (4.8 [4.1-5.5] pmol/l, p = 0.01) adjusting for age, sex and HbA1c. In type 1 diabetes, higher copeptin correlated with lower GFR (r: -0.32, p = 0.01) and higher renin concentration (r: 0.40, p = 0.002) after multivariable adjustments. These relationships were not evident in HC. Copeptin inversely associated with RVR change following exogenous ang II only in participants with type 1 diabetes (β ± SE: -6.9 ± 3.4, p = 0.04). In longstanding type 1 diabetes, copeptin was associated with intrarenal renin-angiotensin-aldosterone system (RAAS) activation and renal hemodynamic function, suggesting interplay between AVP and RAAS in DKD pathogenesis.

Thiazide diuretics and the rate of disease progression in autosomal dominant polycystic kidney disease: an observational study

BackgroundIn autosomal dominant polycystic kidney disease (ADPKD), hypertension is prevalent and cardiovascular events are the main cause of death. Thiazide diuretics are often prescribed as second-line antihypertensives, on top of renin–angiotensin–aldosterone system (RAAS) blockade. There is a concern, however, that diuretics may increase vasopressin concentration and RAAS activity, thereby worsening disease progression in ADPKD. We aimed to investigate the validity of these suggestions.MethodsWe analysed an observational cohort of 533 ADPKD patients. Plasma copeptin (surrogate for vasopressin), aldosterone and renin were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Linear mixed models were used to assess the association of thiazide use with estimated glomerular filtration rate (eGFR) decline and Cox proportional hazards models for the association with the composite kidney endpoint of incident end-stage kidney disease, 40% eGFR decline or death.ResultsA total of 23% of participants (n = 125) used thiazide diuretics at baseline. Compared with non-users, thiazide users were older, a larger proportion was male, they had lower eGFRs and similar blood pressure under more antihypertensives. Plasma copeptin was higher, but this difference disappeared after adjustment for age and sex. Both renin and aldosterone were higher in thiazide users. There was no difference between thiazide users and non-users in the rate of eGFR decline {difference −0.35 mL/min/1.73 m2 per year [95% confidence interval (CI) −0.83 to –0.14], P = 0.2} during 3.9 years of follow-up (interquartile range 2.5–4.9). This did not change after adjustment for potential confounders [difference final model: 0.08 mL/min/1.73 m2 per year [95% CI −0.46 to –0.62], P = 0.8). In the crude model, thiazide use was associated with a higher incidence of the composite kidney endpoint [hazard ratio (HR) 1.53 (95% CI 1.05–2.23), P = 0.03]. However, this association lost significance after adjustment for age and sex and remained unassociated after adjustment for additional confounders [final model: HR 0.80 (95% CI 0.50–1.29), P = 0.4].ConclusionsThese data do not show that thiazide diuretics have a detrimental effect on the rate of disease progression in ADPKD and suggest that these drugs can be prescribed as second-line antihypertensives.