key: cord-0706949-5bu8oo6m
authors: Gregoriano, Claudia; Molitor, Alexandra; Haag, Ellen; Kutz, Alexander; Koch, Daniel; Haubitz, Sebastian; Conen, Anna; Bernasconi, Luca; Hammerer-Lercher, Angelika; Fux, Christoph A; Mueller, Beat; Schuetz, Philipp
title: Activation of vasopressin system during COVID-19 is associated with adverse clinical outcomes: an observational study
date: 2021-03-17
journal: J Endocr Soc
DOI: 10.1210/jendso/bvab045
sha: b15a2f542e9ed53984d60f3fe9357d36c0981542
doc_id: 706949
cord_uid: 5bu8oo6m

BACKGROUND: Activation of the vasopressin system plays a key role for the maintenance of osmotic, cardiovascular and stress hormone homeostasis during disease. We investigated levels of copeptin, the C-terminal segment of the vasopressin prohormone, that mirrors the production rate of vasopressin in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We measured levels of copeptin on admission and after 3/4, 5/6 and 7/8 days in 74 consecutive hospitalized adult COVID-19 patients and compared its prognostic accuracy to that of patients with community-acquired pneumonia (n=876) and acute or chronic bronchitis (n=371) from a previous study by means of logistic regression analysis. The primary endpoint was all-cause 30-day mortality. RESULTS: Median admission copeptin levels in COVID-19 patients were almost 4-fold higher in non-survivors compared to survivors (49.4 pmol/L (IQR 24.9-68.9 pmol/L) vs. 13.5 pmol/L (IQR 7.0-26.7 pmol/L) resulting in an age and gender-adjusted odds ratio of 7.0 (95%CI 1.2 to 40.3), p<0.03 for mortality. Higher copeptin levels in non-survivors persisted during the short-term follow-up. Compared to the control group patients with acute/chronic bronchitis and pneumonia, COVID-19 patients did not have higher admission copeptin levels. CONCLUSIONS: A pronounced activation of the vasopressin system in COVID-19 patients is associated with an adverse clinical course in COVID-19 patients. This finding, however, is not unique to COVID-19 but similar to other types of respiratory infections. .

This prospective observational study included consecutively hospitalized adult patients (≥18 years) admitted during the first wave due to confirmed SARS-CoV-2 infection at the Cantonal Hospital Aarau, a tertiary care medical center in Switzerland, between February 26, 2020 and April 30, 2020. Written general informed consent was provided from all analyzed patients. The study was approved by the local ethical committee (EKNZ, 2020-01306) and performed in conformance with the Declaration of Helsinki ethical guidelines.

Baseline characteristics of is cohort has been published recently including a detailed description of the study methodology (10). In brief, COVID-19 was defined by a positive real-time reverse transcription polymerase chain reaction (RT-PCR) taken from nasopharyngeal swabs or lower respiratory tract specimens, according to the World Health Organization (WHO) guidelines (11). Most patients presented with typical clinical symptoms (e.g. respiratory symptoms with or without M a n u s c r i p t 4 fever, and/or pulmonary infiltrates and/or anosmia/dysgeusia). All data of interest was assessed as part of the clinical routine during hospitalization.

Clinical information, including demographics and comorbidities, pre-existing medical prescriptions and COVID-19-specific in-patient medication were assessed until hospital discharge or death and extracted from the electronic health records. Experimental antiviral treatment was recorded if given and included at this time hydroxychloroquine (alone or in combination with azithromycin) and occasionally tocilizumab. Comorbidities were also assessed via chart review and based on International Statistical Classification of Diseases and Related Health Problems codes (ICD10). Subsequently, patient outcomes including admission to the intensive care unit (ICU), length of hospital stay (LOS), and length of ICU stay were collected via chart review. 30-day mortality, was collected by abstraction of hospital records. Laboratory test results were available according to clinical routine. Copeptin was batch-tested later and was therefore not available to the treating team during the index hospitalization.

We used patients with confirmed community-acquired pneumonia or acute and chronic bronchitis included in a previous prospective study as a control group (12) (13) (14) . In brief, from October 2006 to March 2008 consecutive patients with respiratory infection from six different hospitals located in the northern part of Switzerland were included and prospectively followed for the assessment of mortality and other endpoints. Within this previous study, copeptin levels were measured on admission in all patients to understand its prognostic significance regarding 30 days mortality.

The primary endpoint of the current study was all cause 30-day mortality. For both the COVID-19 patients and the control group, we assessed vital status 30 days after admission by abstraction of hospital records and systematic telephone interviews with patients, their families, or their primary care physicians.

Following hospital admission, plasma and serum samples were collected in BD Vacutainer® Heparin and SST tubes, and leftover samples were stored at -80°C until analysis. Results from routine laboratory tests were recorded. Copeptin was assessed in batch using a commercially available automated fluorescent sandwich immunoassay (KRYPTOR™, B.R.A.H.M.S Thermo Fisher Scientific, Germany), as described in detail elsewhere (15, 16) . The immunoassay has a limit of detection (LOD) of 0.9 pmol/L and the functional assay sensitivity -defined as concentration with an inter-assay coefficient of variation of <20% -was 2.0 pmol/L. Values for the analytes followed Gaussian distribution in healthy individuals without significant difference between males and females as listed A c c e p t e d M a n u s c r i p t 5 in the assay documentation. Laboratory technicians measuring copeptin were blinded to patient characteristics and study details.

For the SARS-CoV-2 affected patients different time points during hospitalization were analyzed, namely T 0 (initial blood draw upon hospital admission), T 1 (day 3/ day 4), T 2 (day 5/ day 6) and T 3 (day 7/ day 8). For the control group, blood samples for biomarker measurement were upon hospital admission. Copeptin levels for these patients were batch-measured in plasma with sandwich immunoassays (Kryptor ® Thermo Scientific Biomarkers) (13).

Discrete variables are expressed as frequency (%) and continuous variables as medians with interquartile ranges (IQR) or mean with standard deviation (SD). A multivariable logistic regression model was used to examine the association of copeptin levels with the primary endpoint. As predefined, regression models were adjusted for age, gender (model 1), and additionally sodium concentration at admission, cancer, coronary artery disease chronic kidney disease, diabetes and glucose concentration at admission (model 2). Odds ratios (OR) and corresponding 95% confidence intervals (CI) were reported as a measure of association and C-statistics (area under the operating receiver curve (ROC-AUC)) as a measure of discrimination. We also validated the prognostic value of different predefined copeptin cut-offs to predict all-cause 30-day mortality which were based on distribution in the analyzed study population .. A two-sided p-value of <0.05 was considered significant. Statistical analysis was performed using Stata 15.1 (StataCorp, College Station, TX, USA).

Overall, 103 patients with confirmed COVID-19 (74 were admitted directly and 29 were transferred from other hospitals) were eligible. Four patients were excluded from the analysis (decline of general consent). Further 25 cases had to be excluded because of missing aliquots for biomarker analysis (n=9), or due to missing initial blood sampling 24 hours from admission (n=16). Thus, in total, 74 COVID-19 patients were included in the final analysis. In addition, 1,247 control patients used with a final diagnosis of pneumonia (n = 876) and acute or chronic bronchitis (n=371). Figure 1 provides an overview of the study flow. Table 1 shows patients demographics, comorbidities as well as vital signs, laboratory findings and outcomes within 30 days in all patients and stratified by type of respiratory infection. Overall, patients with a diagnosis of COVID-19 were younger and more often male compared to the control groups. Further, patients with COVID-19 had higher initial blood pressure values with median systolic blood pressure of 141.5 mmHg (IQR 126.0 to 156.0 mmHg), and diastolic blood pressure of 81.5 mmHg (IQR 72.0 to 88.0 mmHg) (p<0.01). COVID-19 patients also had a higher prevalence of obesity (p=0.01) but a lower prevalence of chronic heart failure (p<0.01) as well as of chronic obstructive pulmonary disease (p<0.01) compared to the non-COVID-19 patients, while no significant differences M a n u s c r i p t 6 could be observed when comparing other comorbidities. Initial laboratory findings showed more severe deterioration in blood gas analysis especially regarding PCO 2-values in COVID-19 patients at ambient air as well as with initial O 2 -supply and for FiO2-value compared to the other control patients (p<0.01, each). Regarding 30-day outcomes, COVID-19 patients had higher rates of all-cause mortality and admission to ICU (p<0.01, each). Length of stay was slightly longer in COVID-19 patients (p=0.09).

Median admission copeptin levels in COVID-19 patients were almost 4-fold higher in non-survivors compared to survivors (49.4 pmol/L (IQR 24.9 -68.9 pmol/L) vs. 13.5 pmol/L (IQR 7.0 -26.7 pmol/L), p<0.01). This was similar also among the other patient groups, where again non-survivors had significantly higher copeptin levels at admission compared to survivors. However, regarding admission copeptin, median levels were not higher in COVID-19 patients compared to non-COVID-19 patients (pneumonia and acute/chronic bronchitis patients) (18.6 pmol/L 22.1 pmol/L, p=0.17). Table 2 gives an overview of copeptin median levels as well as groups stratified according to copeptin among the different types of infections.

For COVID-19 patients, the resulting age and gender-adjusted odds ratio of admission copeptin was 7.0 (95%CI 1.2 to 40.3, p<0.03) and 5.3 (95%CI 0.7 to 40.8, p=0.11) when additionally adjusted for sodium concentration at admission and different comorbidities ( Table 3) for predicting 30-day mortality. For patients with pneumonia and acute or chronic bronchitis, copeptin the association of copeptin levels and mortality was even stronger and remained significant in the fully adjusted multivariate analyses. Regarding discrimination, copeptin had accuracy for all groups, with highest AUC values for acute or chronic bronchitis (AUC 0.89) and for COVID-19 (AUC 0.81), and lower for pneumonia (AUC 0.73).

In addition, the prognostic accuracy of copeptin for 30-day mortality was analyzed for different cutoffs ( Table 4 ). Based on the Youden's index, we found an optimal cut-off at 20.0 pmol/L -which produced a sensitivity to correctly predict 30-day mortality of 88.2% (95% CI 63.6 to 98.5%), and a specificity of 64.9% (95% CI 51.1 to 77.1%). Furthermore, the cut-off at 20.0 pmol/L revealed the highest negative predictive value of 94.9 (95% CI 82.7 to 99.4%). The use of a lower cut-off at 8.0 pmol/L showed a higher sensitivity of 94.1% (95% CI 71.3 to 99.9%) but a very low specificity with 29.8% (95% CI 18.4 to 43.4%). In contrast, a higher cut-off at 40.0 pmol/L reached a high specificity of 86.0% (95% CI 74.2 to 93.7) but only a low sensitivity of 58.8% (95% CI 32.9 to 81.6). Figure 2 illustrates the kinetics of copeptin levels during the follow-up period stratified by survival status. Copeptin values were significantly higher in non-survivors at every time point measured compared to patients who survived. Notably, levels of copeptin in survivors remained in a lower range during the whole follow-up period, but were still in non-physiological range, whereas in non-M a n u s c r i p t 7 survivors, values were high and reached the peak in the second half of hospitalization at days 5 and 6.

The results of this prospective study comparing levels of copeptin in patients with COVID-19 with those of patients with other types of respiratory infections, and among survivors and non-survivors has two main findings. First, we observed that admission levels of copeptin -a marker which mirrors activation of the vasopressin system and thus the individual stress response -were increased 4-fold in patients with a COVID-19 diagnosis who had a fatal outcome compared to survivors and were, therefore, strongly associated with 30-day mortality. This result also remained significant in statistical models adjusted for age and gender but not in the fully adjusted model also including hyponatremia, like shown for pneumonia and acute or chronic bronchitis. This suggests that the activation of the vasopressin system plays an important role in COVID-19 disease particularly regarding a severe course of disease. Second, this finding was not specific for COVID-19 but was similar to other types of viral and bacterial respiratory tract infections. Therefore, these results suggest that the activation of the vasopressin system is not specific to COVID-19 but a more general adaptation of severe respiratory disease. In turn, copeptin may allow individual and early risk stratification and monitoring of patients with respiratory infections including COVID-19.

Although survivors had significantly lower levels of copeptin at admission and during the follow ups, the levels were not in a normal low range, but still elevated compared to healthy persons with a median concentration of 4.2 pmol/L (17) .

Our data is in line with earlier studies demonstrating that infectious diseases such as pneumonia and other respiratory infections can markedly increase circulating levels of copeptin (18) (19) (20) (21) (22) (23) . Several mechanisms may be responsible for this increase. Similar to other respiratory infections, severe disease and thus physiological stress caused by SARS-CoV-2 may trigger the release of the stress marker copeptin aiming to increase free water resorption in the kidneys and thus maintaining blood pressure homeostasis through V2 receptors and producing vasocontriction of blood vessels through V1 receptors (24-26). According to our data septic conditions such as pneumonia had a higher increase in copeptin which may reflects more blood pressure disturbances and shock compared to viral infections. Copeptin levels may go in parallel with the inflammatory cytokine response which is quite strong in SARS-CoV-2 disease (27). Pneumonia and other respiratory diseases are associated with syndrome of (in)appropriate antidiuretic hormone secretion (SIADH) which in turn leads to hyponatremia (28), especially if associated with salt-restricted diet and disease-related malnutrition. In our sample, hyponatremia was a frequent finding in patients. A recently published case series indeed confirmed that three patients with confirmed COVID-19 and suffering from hyponatremia showed a SIADH constellation with euvolemic hyponatremia a high urine osmolality (8). Besides the intravascular volume depletion due to the infection (29, 30), also emotional, physical or psychological stress as well as pain and certain medication like opiates, which can be associated with an infection like COVID-19 can stimulate the release of antidiuretic hormone (ADH) (31). This in turn, correlates with the severity of the disease and with individual stress levels found in lower respiratory tract infections (21). M a n u s c r i p t 8 Our findings suggest that copeptin can mirror disease severity and differentiate patients with fatal outcome from survivors. This was true on admission but also during follow-up. Similar findings were also shown in our study investigating the association of prognostic accuracy of initial and follow-up midregional pro-adrenomedullin (MR-proADM) levels with in-hospital mortality in patients with confirmed SARS-CoV-2 infection (32), In fact, our findings confirms that increased levels of MR-proADM on admission and during hospital stay were independently associated with in-hospital mortality and may allow a better risk stratification, and particularly rule-out of fatal outcome, in COVID-19 patients (32).

Our analysis is in line with copeptin data in other populations such as sepsis patients (33, 34), respiratory infection patients (22, 23) and also stroke patients (35-40). In addition, copeptin was also found to be of prognostic importance in ventilator-associated pneumonia (VAP) (41), and community acquired pneumonia (42). We found an optimal cut-off at 20.0 pmol/L in COVID-19 patients. At this levels, copeptin provides additional information regarding disease progression and risk of 30-day mortality. Interestingly, our optimal cut-off (20. 

This study has several limitations: Firstly, the number of analyzed COVID-19 patients was small with a single center design. Secondly, not all clinical and laboratory parameters and characteristics were available for all patients, resulting in some missing data. Thirdly, we have not collected the needed clinical data for the current WHO disease criteria. Thus, a proper stratified of the disease severity was not possible. Fourthly, we were not able to give more detail on the pathophysiology behind the increase of Copeptin in COVID-19 and whether therapeutic modulation may have any advantages in patients.

To the best of our knowledge, this is the first study analyzing copeptin levels in patients with confirmed COVID-19. Our data indicate that a pronounced activation of the vasopressin system is associated with an adverse clinical course in COVID-19 patients. This finding, however, is not unique to COVID-19 but similar to other types of respiratory infections. M a n u s c r i p t 9 Abbreviations ACE2, angiotensin-converting-enzyme 2; ACTH, adreno-corticotrophic hormone; ADH, antidiuretic hormone; ARDS, acute respiratory distress syndrome; AUC, area under the curve; AVP, arginine vasopressor; BMI, body-mass-index; bpm, beats per minute; CI, confidence intervals; COVID-19, coronavirus disease 2019; CRP, c-reactive protein; ICD10, international statistical classification of diseases and related health problems codes; ICU, intensive care unit; IQR, interquartile ranges; KSA, cantonal hospital Aarau; LOD, limit of detection; LOS, length of hospital stay; mmHg, millimeter of mercury; MR-proADM, midregional pro-adrenomedullin; NS, non-survivors; OR, odds ratio; PCT, procalcitonin; RAAS, renin-angiotensin-aldosterone-system; ROC-AUC, area under the operating receiver curve; RT-PCR, reverse transcription polymerase chain reaction; S, survivors; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; SD, standard deviation; SIADH, syndrome of (in)appropriate antidiuretic hormone secretion; SpO2, oxygen saturation; VAP, ventilator-associated pneumonia; WHO, World Health Organization.

Some or all datasets generated during and analyzed during the current study are not publicly available but are available from the corresponding author on reasonable request.

CG, AK, and PS had the idea, wrote the protocol and initiated the study. CG managed the trial and collected data. LB and AHL managed the laboratory investigations. CG, DK and SH performed the statistical analyses and CG, AM, AK and PS drafted the manuscript. EH, SH, AC, LB, AHL, CAF and BM, amended and commented on the manuscript. PS and BM provided funding. All authors approved the final version. M a n u s c r i p t 10

Costs for biomarker measurement (reagents) were externally sponsored by ThermoFisher Scientific, BRAHMS, Henningsdorf (Germany). This study was funded by Research Council KSA (Kantonsspital Aarau).

The funding agency have no bearing on the study design, data collection and analysis or writing of the manuscript.

None declared.

None declared. M a n u s c r i p t 22 

Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study

Virological assessment of hospitalized patients with COVID-2019

Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19

COVID-19: the vasculature unleashed

Endothelial cell infection and endotheliitis in COVID-19

Extrapulmonary manifestations of COVID-19

Our Response to COVID-19 as Endocrinologists and Diabetologists

Procalcitonin guided antibiotic therapy and hospitalization in patients with lower respiratory tract infections: a prospective, multicenter, randomized controlled trial

Mid-regional pro-adrenomedullin as a prognostic marker in sepsis: an observational study. Comparative Study Evaluation Studies

Measurement of midregional proadrenomedullin in plasma with an immunoluminometric assay

Assay for the measurement of copeptin, a stable peptide derived from the precursor of vasopressin

Prohormones for prediction of adverse medical outcome in community-acquired pneumonia and lower respiratory tract infections

Assessment of inflammatory markers in patients with community-acquired pneumonia--influence of antimicrobial pretreatment: results from the German competence network CAPNETZ

Copeptin, a stable peptide derived from the vasopressin precursor, is elevated in serum of sepsis patients

Abbreviations: BMI, body mass index; bpm, beats per minute; CRP, C -reactive protein

IQR, interquartile range; mmHg, millimeter of mercury; PCT, procalcitonin; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2

Values are referring to SARS-CoV-2 vs. Non-SARS-CoV-2 (Pneumonia + acute or chronic bronchitis) (95% CI)

Abbreviations: CI, confidence interval

We thank all participating patients and their families, and all healthcare workers at the Cantonal Hospital Aarau for their great dedication to reducing the burden of this severe disease. We thank Erica Holt for native English review.

A c c e p t e d M a n u s c r i p t 19 n (%) Liver cirrhosis, n (%) 19 A c c e p t e d M a n u s c r i p t A c c e p t e d M a n u s c r i p t 23 A c c e p t e d M a n u s c r i p t 26 Figure 1 A c c e p t e d M a n u s c r i p t 27 Figure 2