{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T05:15:23Z","timestamp":1783487723114,"version":"3.55.0"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T00:00:00Z","timestamp":1783468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Funding for Scientific Research and Innovation Team of the First Affiliated Hospital of Zhengzhou University, China","award":["QNCXTD2023014"],"award-info":[{"award-number":["QNCXTD2023014"]}]},{"name":"Young and Middle-aged Academic Leaders of Health Commission of Henan Province, China","award":["HNSWJW-2023029"],"award-info":[{"award-number":["HNSWJW-2023029"]}]},{"name":"Program for Science and Technology Innovation Talents in Universities of Henan Province, China","award":["24HASTIT064"],"award-info":[{"award-number":["24HASTIT064"]}]},{"name":"Henan Provincial Science Fund for Distinguished Young Scholars, China","award":["232300421011"],"award-info":[{"award-number":["232300421011"]}]},{"name":"Henan Provincial Clinical Medical Scientist Program, China","award":["HNCMS202416"],"award-info":[{"award-number":["HNCMS202416"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82270629"],"award-info":[{"award-number":["82270629"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Fasting before routine blood sampling has been regarded as a standard requirement. However, this practice may cause unnecessary discomfort and lacks sufficient scientific evidence. This study aimed to investigate the effect of water intake on commonly measured complete blood count (CBC) and biochemical parameters.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>\n                      This two-step study involved two homogeneous cohorts of healthy adult medical postgraduate students. In Step 1, participants from Cohort 1 (\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f38) underwent standard fasting conditions to establish the short-term biological variation (BV) and corresponding reference change values (RCVs). In Step 2, participants from Cohort 2 (\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f33) had blood analysis before and one hour after consuming 500\u202fmL water to assess the resulting changes, and only mean differences (MDs) exceeding the corresponding RCVs were considered clinically significant.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Twelve CBC parameters and 7 biochemical parameters showed statistically significant differences one hour after the intake of 500\u202fmL of water compared with pre-intake values, including leukocytes, lymphocytes, monocytes, erythrocytes, hemoglobin, hematocrit, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, red cell distribution width\u2013standard deviation, platelets, plateletcrit, alkaline phosphatase, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, urea, uric acid, and creatinine. The remaining 6 CBC parameters and 5 biochemical parameters showed no statistically significant differences, including neutrophils, eosinophils, basophils, mean platelet volume, platelet distribution width, platelet larger cell ratio, alanine aminotransferase, aspartate aminotransferase,\n                      <jats:italic>\u03b3<\/jats:italic>\n                      -glutamyltransferase, triglyceride, and glucose. Notably, only the change of lymphocytes was considered clinically significant.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Water intake before routine blood sampling has minimal clinically relevant effects on commonly measured CBC and biochemical parameters in healthy adults.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2026.1884690","type":"journal-article","created":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T04:36:35Z","timestamp":1783485395000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of water intake on routine laboratory test parameters in healthy adults: a cross-sectional study"],"prefix":"10.3389","volume":"13","author":[{"given":"Zhuang-Zhuang","family":"Zhai","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xue-Jing","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ru-Yue","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xue-Yan","family":"Lv","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yue-Hang","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Bai","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qing-Lei","family":"Zeng","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, The First Affiliated Hospital of Zhengzhou University","place":["Zhengzhou, Henan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,8]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1709","DOI":"10.1515\/cclm-2025-0190","article-title":"Pre-analytical phase errors constitute the vast majority of errors in clinical laboratory testing","volume":"63","author":"Lin","year":"2025","journal-title":"Clin Chem Lab Med"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"732","DOI":"10.1515\/cclm-2022-1036","article-title":"The preanalytical phase - from an instrument-centred to a patient-centred laboratory medicine","volume":"61","author":"Cadamuro","year":"2023","journal-title":"Clin Chem Lab Med"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"326","DOI":"10.11613\/bm.2013.040","article-title":"Are patients well informed about the fasting requirements for laboratory blood testing?","volume":"23","author":"Kackov","year":"2013","journal-title":"Biochem Med (Zagreb)"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"158","DOI":"10.1515\/CCLM.2007.052","article-title":"Patient hydration: a major source of laboratory uncertainty","volume":"45","author":"Ritchie","year":"2007","journal-title":"Clin Chem Lab Med"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"343","DOI":"10.3343\/alm.2025.0022","article-title":"Standards and practice guidelines for venous blood collection: consensus recommendations from the Korean Society for Laboratory Medicine","volume":"45","author":"Chang","year":"2025","journal-title":"Ann Lab Med"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1016\/j.jacl.2021.09.046","article-title":"Lipid measurements in the management of cardiovascular diseases: practical recommendations a scientific statement from the National Lipid Association writing group","volume":"15","author":"Wilson","year":"2021","journal-title":"J Clin Lipidol"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"020703","DOI":"10.11613\/BM.2025.020703","article-title":"Evaluation of the impact of reducing fasting hours on laboratory results in a Mediterranean population","volume":"35","author":"Sol\u00e9-Enrech","year":"2025","journal-title":"Biochem Med (Zagreb)"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"741","DOI":"10.1515\/cclm-2022-1255","article-title":"Biological variation: recent development and future challenges","volume":"61","author":"Sandberg","year":"2023","journal-title":"Clin Chem Lab Med"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"807","DOI":"10.1515\/cclm.2011.733","article-title":"Reference change values","volume":"50","author":"Fraser","year":"2011","journal-title":"Clin Chem Lab Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"307","DOI":"10.1093\/clinchem\/hvae166","article-title":"Estimating reference change values using routine patient data: a novel pathology database approach","volume":"71","author":"R\u00f8ys","year":"2025","journal-title":"Clin Chem"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"437","DOI":"10.1016\/j.cca.2021.10.006","article-title":"Problems with estimating reference change values (critical differences)","volume":"523","author":"Haeckel","year":"2021","journal-title":"Clin Chim Acta"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"501","DOI":"10.1373\/clinchem.2017.281808","article-title":"The biological variation data critical appraisal checklist: a standard for evaluating studies on biological variation","volume":"64","author":"Aarsand","year":"2018","journal-title":"Clin Chem"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"505","DOI":"10.1515\/cclm-2021-0370","article-title":"The European biological variation study (EuBIVAS): a summary report","volume":"60","author":"Carobene","year":"2022","journal-title":"Clin Chem Lab Med"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"110","DOI":"10.1515\/cclm-2024-0672","article-title":"The biological variation of insulin resistance markers: data from the European biological variation study (EuBIVAS)","volume":"63","author":"Carobene","year":"2025","journal-title":"Clin Chem Lab Med"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"725","DOI":"10.1373\/clinchem.2015.252296","article-title":"Biological variation: the effect of different distributions on estimated within-person variation and reference change values","volume":"62","author":"R\u00f8raas","year":"2016","journal-title":"Clin Chem"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"1648","DOI":"10.1515\/cclm-2021-0928","article-title":"Biological variation estimates obtained from Chinese subjects for 32 biochemical measurands in serum","volume":"60","author":"Ma","year":"2022","journal-title":"Clin Chem Lab Med"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"010702","DOI":"10.11613\/bm.2018.010702","article-title":"Fasting conditions: influence of water intake on clinical chemistry analytes","volume":"28","author":"Benozzi","year":"2018","journal-title":"Biochem Med"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"126","DOI":"10.1016\/j.cca.2018.04.019","article-title":"Preanalytical phase: effects of water ingestion during fasting on routine hematological parameters in a small cohort of young women","volume":"483","author":"Unger","year":"2018","journal-title":"Clin Chim Acta"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"2015","DOI":"10.1515\/cclm-2018-0602","article-title":"Joint EFLM-COLABIOCLI recommendation for venous blood sampling","volume":"56","author":"Simundic","year":"2018","journal-title":"Clin Chem Lab Med"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"e367","DOI":"10.1055\/s-0039-3401002","article-title":"Breakfast can affect routine hematology and coagulation laboratory testing: an evaluation on behalf of COLABIOCLI WG-PRE-LATAM","volume":"3","author":"Arredondo","year":"2019","journal-title":"TH Open"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"871","DOI":"10.1515\/cclm-2014-1133","article-title":"Reliability of biological variation data available in an online database: need for improvement","volume":"53","author":"Carobene","year":"2015","journal-title":"Clin Chem Lab Med"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"313","DOI":"10.3109\/10408363.2016.1150252","article-title":"Generation of data on within-subject biological variation in laboratory medicine: an update","volume":"53","author":"Braga","year":"2016","journal-title":"Crit Rev Clin Lab Sci"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"3416","DOI":"10.1111\/jocn.14918","article-title":"Comparisons of laboratory results between two blood samplings: venipuncture versus peripheral venous catheter-a systematic review with meta-analysis","volume":"28","author":"Jeong","year":"2019","journal-title":"J Clin Nurs"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"1013","DOI":"10.1515\/cclm-2016-0716","article-title":"Within-day biological variation and hour-to-hour reference change values for hematological parameters","volume":"55","author":"Hilderink","year":"2017","journal-title":"Clin Chem Lab Med"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"2313","DOI":"10.1111\/jan.14078","article-title":"Drawing blood from peripheral intravenous cannula compared with venepuncture: a systematic review and meta-analysis","volume":"75","author":"Coventry","year":"2019","journal-title":"J Adv Nurs"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"112","DOI":"10.1055\/s-0041-1726669","article-title":"Performance of 3 mL versus 5 mL discarded volume for blood sampling from central venous access device","volume":"13","author":"Lalthanthuami","year":"2021","journal-title":"J Lab Physicians"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"1655","DOI":"10.1515\/cclm-2020-0273","article-title":"Exact time of venous blood sample collection - an unresolved issue, on behalf of the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) working Group for Preanalytical Phase (WG-PRE)","volume":"58","author":"von Meyer","year":"2020","journal-title":"Clin Chem Lab Med"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1186\/s12014-025-09551-7","article-title":"Diurnal rhythm of the human plasma proteome","volume":"22","author":"Em","year":"2025","journal-title":"Clin Proteomics"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"374","DOI":"10.1093\/clinchem\/hvaa233","article-title":"Personalized reference intervals in laboratory medicine: a new model based on within-subject biological variation","volume":"67","author":"Co\u015fkun","year":"2021","journal-title":"Clin Chem"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"606","DOI":"10.1515\/cclm-2021-0479","article-title":"Annual biological variation and personalized reference intervals of clinical chemistry and hematology analytes","volume":"60","author":"Wang","year":"2022","journal-title":"Clin Chem Lab Med"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"500","DOI":"10.1093\/clinchem\/hvad006","article-title":"Long-term within- and between-subject biological variation data of hematological parameters in recreational endurance athletes","volume":"69","author":"Diaz-Garzon","year":"2023","journal-title":"Clin Chem"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"519","DOI":"10.1016\/j.cca.2021.11.007","article-title":"Biological variation of thyroid function biomarkers over 24 hours","volume":"523","author":"Zhang","year":"2021","journal-title":"Clin Chim Acta"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"1282","DOI":"10.1515\/cclm-2019-1141","article-title":"Long-term biological variation estimates of 13 hematological parameters in healthy Chinese subjects","volume":"58","author":"Li","year":"2020","journal-title":"Clin Chem Lab Med"}],"container-title":["Frontiers in Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1884690\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T04:36:47Z","timestamp":1783485407000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1884690\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,8]]},"references-count":33,"alternative-id":["10.3389\/fmed.2026.1884690"],"URL":"https:\/\/doi.org\/10.3389\/fmed.2026.1884690","relation":{},"ISSN":["2296-858X"],"issn-type":[{"value":"2296-858X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,8]]},"article-number":"1884690"}}