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Choy KW, Carobene A, Loh TP, Chiang C, Wijeratne N, Locatelli M, Coskun A, Cavusoglu C, Unsal I. Biological Variation Estimates for Plasma Copeptin and Clinical Implications. J Appl Lab Med 2024; 9:430-439. [PMID: 38576222 DOI: 10.1093/jalm/jfae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/15/2023] [Indexed: 04/06/2024]
Abstract
BACKGROUND Plasma copeptin measurement is useful for the differential diagnoses of polyuria-polydipsia syndrome. It has also been proposed as a prognostic marker for cardiovascular diseases. However, limited information is available about the within- (CVI) and between-subject (CVG) biological variation (BV). This study presents BV estimates for copeptin in healthy individuals. METHODS Samples were collected weekly from 41 healthy subjects over 5 weeks and analyzed using the BRAHMS Copeptin proAVP KRYPTOR assay after at least 8 h of food and fluid abstinence. Outlier detection, variance homogeneity, and trend analysis were performed followed by CV-ANOVA for BV and analytical variation (CVA) estimation with 95% confidence intervals. Reference change values (RCVs), index of individuality (II), and analytical performance specification (APS) were also calculated. RESULTS The analysis included 178 results from 20 males and 202 values from 21 females. Copeptin concentrations were significantly higher in males than in females (mean 8.5 vs 5.2 pmol/L, P < 0.0001). CVI estimates were 18.0% (95% CI, 15.4%-21.6%) and 19.0% (95% CI, 16.4%-22.6%), for males and females, respectively; RCVs were -35% (decreasing value) and 54% (increasing value). There was marked individuality for copeptin. No result exceeded the diagnostic threshold (>21.4 pmol/L) for arginine vasopressin resistance. CONCLUSIONS The availability of BV data allows for refined APS and associated II, and RCVs applicable as aids in the serial monitoring of patients with specific diseases such as heart failure. The BV estimates are only applicable in subjects who abstained from oral intake due to the rapid and marked effects of fluids on copeptin physiology.
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Affiliation(s)
- Kay Weng Choy
- Department of Pathology, Northern Health, Epping, Australia
| | - Anna Carobene
- Laboratory Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - Cherie Chiang
- Department of Pathology, The University of Melbourne, Royal Melbourne Hospital, Parkville, Australia
| | - Nilika Wijeratne
- Eastern Health Pathology, Eastern Health, Box Hill, Australia
- Department of Biochemistry, Dorevitch Pathology, Heidelberg, Australia
- School of Clinical Sciences at Monash Health, Department of Medicine, Nursing and Health Sciences, Monash University, Clayton, Australia
| | - Massimo Locatelli
- Laboratory Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Abdurrahman Coskun
- School of Medicine, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Coskun Cavusoglu
- School of Medicine, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Ibrahim Unsal
- School of Medicine, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
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2
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Hasselbalch RB, Alaour B, Kristensen JH, Couch LS, Kaier TE, Nielsen TL, Plesner LL, Strandkjær N, Schou M, Rydahl C, Goetze JP, Bundgaard H, Marber M, Iversen KK. Hemodialysis and biomarkers of myocardial infarction - a cohort study. Clin Chem Lab Med 2024; 62:361-370. [PMID: 37556843 DOI: 10.1515/cclm-2023-0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 07/24/2023] [Indexed: 08/11/2023]
Abstract
OBJECTIVES End-stage renal disease is associated with a high risk of cardiovascular disease. We compared the concentration and prognostic ability of high sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) and cardiac myosin-binding protein C (cMyC) among stable hemodialysis patients. METHODS Patients were sampled before and after hemodialysis. We measured hs-cTnI, hs-cTnT and cMyC and used Cox regressions to assess the association between quartiles of concentrations and all-cause mortality and a combination of cardiovascular events and all-cause mortality during follow-up. RESULTS A total of 307 patients were included, 204 males, mean age 66 years (SD 14). Before dialysis, 299 (99 %) had a hs-cTnT concentration above the 99th percentile, compared to 188 (66 %) for cMyC and 35 (11 %) for hs-cTnI. Hs-cTnT (23 %, p<0.001) and hs-cTnI (15 %, p=0.049) but not cMyC (4 %, p=0.256) decreased during dialysis. Follow-up was a median of 924 days (492-957 days); patients in the 3rd and 4th quartiles of hs-cTnT (3rd:HR 3.0, 95 % CI 1.5-5.8, 4th:5.2, 2.7-9.8) and the 4th quartile of hs-cTnI (HR 3.8, 2.2-6.8) had an increased risk of mortality. Both were associated with an increased risk of the combined endpoint for patients in the 3rd and 4th quartiles. cMyC concentrations were not associated with risk of mortality or cardiovascular event. CONCLUSIONS Hs-cTnT was above the 99th percentile in almost all patients. This was less frequent for hs-cTnI and cMyC. High cTn levels were associated with a 3-5-fold higher mortality. This association was not present for cMyC. These findings are important for management of hemodialysis patients.
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Affiliation(s)
- Rasmus Bo Hasselbalch
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Bashir Alaour
- King's College London British Heart Foundation Centre, Rayne Institute, St Thomas' Hospital, London, UK
| | - Jonas Henrik Kristensen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Liam S Couch
- King's College London British Heart Foundation Centre, Rayne Institute, St Thomas' Hospital, London, UK
| | - Thomas E Kaier
- King's College London British Heart Foundation Centre, Rayne Institute, St Thomas' Hospital, London, UK
| | - Ture Lange Nielsen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Louis Lind Plesner
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Nina Strandkjær
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Morten Schou
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Casper Rydahl
- Department of Nephrology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Jens P Goetze
- Department of Clinical Biochemistry, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Michael Marber
- King's College London British Heart Foundation Centre, Rayne Institute, St Thomas' Hospital, London, UK
| | - Kasper Karmark Iversen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte Hospital, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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3
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Guldhaug NA, Røys EÅ, Viste K, Thorsby PM, Sylte MS, Torsvik J, Strand H, Alaour B, Marber M, Omland T, Aakre KM. Week-to-week within-subject and between-subject biological variation of copeptin. Clin Chem Lab Med 2024; 62:e29-e33. [PMID: 37533276 PMCID: PMC10725185 DOI: 10.1515/cclm-2023-0673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/23/2023] [Indexed: 08/04/2023]
Affiliation(s)
- Nora Alicia Guldhaug
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Eirik Åsen Røys
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Kristin Viste
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Per Medbøe Thorsby
- Hormone Laboratory, Department of Medical Biochemistry and Biochemical Endocrinology and Metabolism Research Group, Oslo University Hospital, Aker, Oslo, Norway
- Institute of Clinical Medicine and University of Oslo, Oslo, Norway
| | | | - Janniche Torsvik
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Heidi Strand
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
| | - Bashir Alaour
- King’s BHF Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King’s College London, London, UK
| | - Michael Marber
- Institute of Clinical Medicine and University of Oslo, Oslo, Norway
| | - Torbjørn Omland
- Institute of Clinical Medicine and University of Oslo, Oslo, Norway
- Department of Cardiology, Division of Medicine, Akershus University Hospital, Lørenskog, Norway
| | - Kristin Moberg Aakre
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
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4
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Rosas PC, Solaro RJ. Implications of S-glutathionylation of sarcomere proteins in cardiac disorders, therapies, and diagnosis. Front Cardiovasc Med 2023; 9:1060716. [PMID: 36762302 PMCID: PMC9902711 DOI: 10.3389/fcvm.2022.1060716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/29/2022] [Indexed: 01/25/2023] Open
Abstract
The discovery that cardiac sarcomere proteins are substrates for S-glutathionylation and that this post-translational modification correlates strongly with diastolic dysfunction led to new concepts regarding how levels of oxidative stress affect the heartbeat. Major sarcomere proteins for which there is evidence of S-glutathionylation include cardiac myosin binding protein C (cMyBP-C), actin, cardiac troponin I (cTnI) and titin. Our hypothesis is that these S-glutathionylated proteins are significant factors in acquired and familial disorders of the heart; and, when released into the serum, provide novel biomarkers. We consider the molecular mechanisms for these effects in the context of recent revelations of how these proteins control cardiac dynamics in close collaboration with Ca2+ fluxes. These revelations were made using powerful approaches and technologies that were focused on thin filaments, thick filaments, and titin filaments. Here we integrate their regulatory processes in the sarcomere as modulated mainly by neuro-humoral control of phosphorylation inasmuch evidence indicates that S-glutathionylation and protein phosphorylation, promoting increased dynamics and modifying the Frank-Starling relation, may be mutually exclusive. Earlier studies demonstrated that in addition to cTnI as a well-established biomarker for cardiac disorders, serum levels of cMyBP-C are also a biomarker for cardiac disorders. We describe recent studies approaching the question of whether serum levels of S-glutathionylated-cMyBP-C could be employed as an important clinical tool in patient stratification, early diagnosis in at risk patients before HFpEF, determination of progression, effectiveness of therapeutic approaches, and as a guide in developing future therapies.
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Affiliation(s)
- Paola C. Rosas
- Department of Pharmacy Practice, College of Pharmacy, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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5
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Røys EÅ, Guldhaug NA, Viste K, Jones GD, Alaour B, Sylte MS, Torsvik J, Kellmann R, Strand H, Theodorsson E, Marber M, Omland T, Aakre KM. Sex Hormones and Adrenal Steroids: Biological Variation Estimated Using Direct and Indirect Methods. Clin Chem 2023; 69:100-109. [PMID: 36373220 DOI: 10.1093/clinchem/hvac175] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Biological variation (BV) data may be used to develop analytical performance specifications (APS), reference change values (RCV), and support the applicability of population reference intervals. This study estimates within-subject BV (CVI) for several endocrine biomarkers using 3 different methodological approaches. METHODS For the direct method, 30 healthy volunteers were sampled weekly for 10 consecutive weeks. Samples were analyzed in duplicate for 17-hydroxyprogesterone (17-OHP), androstenedione, cortisol, cortisone, estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), and testosterone. A CV-ANOVA with outlier removal and a Bayesian model were applied to derive the CVI. For estradiol, FSH and LH, only the male subgroup was included. In the indirect method, using the same analytes and groups, pairs of sequential results were extracted from the laboratory information system. The total result variation for individual pairs was determined by identifying a central gaussian distribution in the ratios of the result pairs. The CVI was then estimated by removing the effect of analytical variation. RESULTS The estimated CVI from the Bayesian model (μCVP(i)) in the total cohort was: 17-OHP, 23%; androstenedione, 20%; cortisol, 18%; cortisone, 11%; SHBG, 7.4%; testosterone, 16%; and for the sex hormones in men: estradiol, 14%; FSH, 8%; and LH, 26%. CVI-heterogeneity was present for most endocrine markers. Similar CVI data were estimated using the CV-ANOVA and the indirect method. CONCLUSIONS Similar CVI data were obtained using 2 different direct and one indirect method. The indirect approach is a low-cost alternative ensuring implementation of CVI data applicable for local conditions.
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Affiliation(s)
- Eirik Åsen Røys
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Nora Alicia Guldhaug
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Kristin Viste
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Graham Dallas Jones
- Department of Chemical Pathology, SydPath, St. Vincent's Hospital, Sydney, Darlinghurst, NSW, Australia.,Faculty of Medicine, University of New South Wales, Kensington, NSW, Australia
| | - Bashir Alaour
- King's BHF Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | | | - Janniche Torsvik
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Ralf Kellmann
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Heidi Strand
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
| | - Elvar Theodorsson
- Department of Clinical Chemistry, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Michael Marber
- King's BHF Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - Torbjørn Omland
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Cardiology, Division of Medicine, Akershus University Hospital, Lørenskog, Norway
| | - Kristin Moberg Aakre
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
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6
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Sandberg S, Carobene A, Aarsand AK. Biological variation - eight years after the 1st Strategic Conference of EFLM. Clin Chem Lab Med 2022; 60:465-468. [PMID: 35138052 DOI: 10.1515/cclm-2022-0086] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sverre Sandberg
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway.,Department of Medical Biochemistry and Pharmacology, Norwegian Porphyria Centre, Haukeland University Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Anna Carobene
- Laboratory Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Aasne K Aarsand
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway.,Department of Medical Biochemistry and Pharmacology, Norwegian Porphyria Centre, Haukeland University Hospital, Bergen, Norway
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7
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Aakre KM, Ottesen AH, Strand H, Faaren AL, Alaour B, Torsvik J, Sylte MS, Marber M, Christensen G, Røsjø H, Omland T. Biological variation of secretoneurin; a novel cardiovascular biomarker implicated in arrhythmogenesis. Clin Biochem 2021; 98:74-77. [PMID: 34624255 DOI: 10.1016/j.clinbiochem.2021.09.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/24/2021] [Accepted: 09/30/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Secretoneurin is a novel prognostic biomarker that may predict mortality in heart failure and the occurrence of ventricular arrhythmias. This study reports the within subject variation (CVI), between subject variation (CVG), reference change values (RCV) and index of individuality (II) of secretoneurin. METHODS Thirty healthy volunteers were included. Non-fasting samples were obtained between 8 and 10 am once a week for ten weeks. Secretoneurin was analyzed in duplicate using ELISA. No outliers were present according to Burnett and Reeds' criteria. Simple linear regression did not identify significant trends. Variance homogeneity in the analytical variance and CVI were tested using Cochrane's and Bartlett's tests and four participants were excluded. Calculation of CVI, CVG and RCV were done on ln transformed data as described by Fokkema, the II was calculated using retransformed data. RESULTS The median age of the participants was 36 years and 53% were female. Non-fasting glucose, eGFR(CKD-EPI), cTnT and NT-proBNP concentrations were within the normal range. Median secretoneurin concentrations were 38 pmol/L (women) and 33 pmol/L (men), p-value < 0.001. CVI and CVG were 9.8% (CI 8.7% to 11.0%) and 20.0 (CI 15.4% to 28.0%), respectively. RCV were 38.7% (CI 35.5% to 42.7%) and -27.9 (CI -29.9 to -26.2) and the II were 0.60 (CI 0.42-0.78). No gender differences were present. CONCLUSION Secretoneurin has a fairly low CVI, CVG, RCV and II, indicating that it could be suitable as a diagnostic or prognostic biomarker and that delta values in serial samplings may be preferable for identifying clinical changes.
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Affiliation(s)
- Kristin M Aakre
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway; Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway.
| | - Anett H Ottesen
- Division of Research and Innovation, Akershus University Hospital, Lørenskog, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Heidi Strand
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
| | | | - Bashir Alaour
- School of Cardiovascular Medicine and Sciences, King's College London, United Kingdom
| | - Janniche Torsvik
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Marit S Sylte
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Michael Marber
- School of Cardiovascular Medicine and Sciences, King's College London, United Kingdom
| | - Geir Christensen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Helge Røsjø
- Division of Research and Innovation, Akershus University Hospital, Lørenskog, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Torbjørn Omland
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Cardiology, Division of Medicine, Akershus University Hospital, Lørenskog, Norway
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8
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Sithiravel C, Røysland R, Alaour B, Sylte MS, Torsvik J, Strand H, Marber M, Omland T, Aakre KM. Biological variation, reference change values and index of individuality of GDF-15. Clin Chem Lab Med 2021; 60:593-596. [PMID: 34644816 PMCID: PMC8997700 DOI: 10.1515/cclm-2021-0769] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/21/2021] [Indexed: 01/11/2023]
Affiliation(s)
- Cindhya Sithiravel
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
| | - Ragnhild Røysland
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Bashir Alaour
- School of Cardiovascular Medicine and Sciences, King’s College London, London, UK
| | | | - Janniche Torsvik
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Heidi Strand
- Multidisciplinary Laboratory Medicine and Medical Biochemistry, Akershus University Hospital, Lørenskog, Norway
| | - Michael Marber
- School of Cardiovascular Medicine and Sciences, King’s College London, London, UK
| | - Torbjørn Omland
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Cardiology, Division of Medicine, Akershus University Hospital, Lørenskog, Norway
| | - Kristin Moberg Aakre
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
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