{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T12:27:32Z","timestamp":1777552052097,"version":"3.51.4"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,29]],"date-time":"2023-01-29T00:00:00Z","timestamp":1674950400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Dysnatraemias are commonly reported in COVID-19. However, the clinical epidemiology of hypernatraemia and its impact on clinical outcomes in relation to different variants of SARS-CoV-2, especially the prevailing Omicron variant, remain unclear. Methods: This was a territory-wide retrospective study to investigate the clinical epidemiology and outcomes of COVID-19 patients with hypernatraemia at presentation during the period from 1 January 2020 to 31 March 2022. The primary outcome was 30-day mortality. Key secondary outcomes included rates of hospitalization and ICU admission, and costs of hospitalization. Results: In this study, 53,415 adult COVID-19 patients were included for analysis. Hypernatraemia was observed in 2688 (5.0%) patients at presentation, of which most cases (99.2%) occurred during the local \u201c5th wave\u201d dominated by the Omicron BA.2 variant. Risk factors for hypernatraemia at presentation included age, institutionalization, congestive heart failure, dementia, higher SARS-CoV-2 Ct value, white cell count, C-reactive protein and lower eGFR and albumin levels (p &lt; 0.001 for all). Patients with hypernatraemia showed significantly higher 30-day mortality (32.0% vs. 5.7%, p &lt; 0.001) and longer lengths of stay (12.9 \u00b1 10.9 vs. 11.5 \u00b1 12.1 days, p &lt; 0.001) compared with those with normonatraemia. Multivariate analysis revealed hypernatraemia at presentation as an independent predictor for 30-day mortality (aHR 1.32, 95% CI 1.14\u20131.53, p &lt; 0.001) and prolonged hospital stays (OR 1.55, 95% CI 1.17\u20132.05, p = 0.002). Conclusions: Hypernatraemia is common among COVID-19 patients, especially among institutionalized older adults with cognitive impairment and other comorbidities during large-scale outbreaks during the Omicron era. Hypernatraemia is associated with unfavourable outcomes and increased healthcare utilization.<\/jats:p>","DOI":"10.3390\/jcm12031042","type":"journal-article","created":{"date-parts":[[2023,1,30]],"date-time":"2023-01-30T01:33:37Z","timestamp":1675042417000},"page":"1042","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Epidemiology and Outcomes of Hypernatraemia in Patients with COVID-19\u2014A Territory-Wide Study in Hong Kong"],"prefix":"10.3390","volume":"12","author":[{"given":"Benjamin Y. F.","family":"So","sequence":"first","affiliation":[{"name":"Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5205-9440","authenticated-orcid":false,"given":"Chun Ka","family":"Wong","sequence":"additional","affiliation":[{"name":"Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4681-7326","authenticated-orcid":false,"given":"Gordon Chun Kau","family":"Chan","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9549-9611","authenticated-orcid":false,"given":"Jack Kit Chung","family":"Ng","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5242-2967","authenticated-orcid":false,"given":"Grace Chung Yan","family":"Lui","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8898-8505","authenticated-orcid":false,"given":"Cheuk Chun","family":"Szeto","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1556-2538","authenticated-orcid":false,"given":"Ivan Fan Ngai","family":"Hung","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hung Fat","family":"Tse","sequence":"additional","affiliation":[{"name":"Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sydney C. W.","family":"Tang","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tak Mao","family":"Chan","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5310-5197","authenticated-orcid":false,"given":"Kai Ming","family":"Chow","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Desmond Y. H.","family":"Yap","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"CR729","DOI":"10.12659\/MSM.883600","article-title":"Community-acquired hypernatremia in elderly and very elderly patients admitted to the hospital: Clinical characteristics and outcomes","volume":"18","author":"Turgutalp","year":"2012","journal-title":"Med. Sci. Monit."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Bozkurt Babus, S., Kose, A., Erdogan, S., Kiraz, M., and Iyikesici, F. (2022). Risk factors and mortality in elderly patients with severe hyponatremia admitted to the emergency department. Ir. J. Med. Sci., 1\u201310.","DOI":"10.1007\/s11845-022-02989-w"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.ejim.2020.10.003","article-title":"Hypernatremia and moderate-to-severe hyponatremia are independent predictors of mortality in septic patients at emergency department presentation: A sub-group analysis of the need-speed trial","volume":"83","author":"Castello","year":"2021","journal-title":"Eur. J. Intern. Med."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Lindner, G., Herschmann, S., Funk, G.C., Exadaktylos, A.K., Gygli, R., and Ravioli, S. (2022). Sodium and potassium disorders in patients with COPD exacerbation presenting to the emergency department. BMC Emerg. Med., 22.","DOI":"10.1186\/s12873-022-00607-7"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3859","DOI":"10.1016\/j.arth.2021.08.006","article-title":"Sodium Abnormalities Are an Independent Predictor of Complications in Total Joint Arthroplasty: A Cautionary Tale!","volume":"36","author":"Wester","year":"2021","journal-title":"J. Arthroplast."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1097\/MNH.0000000000000773","article-title":"Hypernatremia in the intensive care unit","volume":"31","author":"Chand","year":"2022","journal-title":"Curr. Opin. Nephrol. Hypertens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.1111\/j.1532-5415.2006.00807.x","article-title":"Clinical presentation of hypernatremia in elderly patients: A case control study","volume":"54","author":"Chassagne","year":"2006","journal-title":"J. Am. Geriatr. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"599255","DOI":"10.3389\/fendo.2020.599255","article-title":"Prognostic Impact of Hyponatremia and Hypernatremia in COVID-19 Pneumonia. A HOPE-COVID-19 (Health Outcome Predictive Evaluation for COVID-19) Registry Analysis","volume":"11","author":"Cuesta","year":"2020","journal-title":"Front. Endocrinol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"666949","DOI":"10.3389\/fmed.2021.666949","article-title":"The Prognostic Value of Hyponatremia for Predicting Poor Outcome in Patients with COVID-19: A Systematic Review and Meta-Analysis","volume":"8","author":"Akbar","year":"2021","journal-title":"Front. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1007\/s40620-021-01036-8","article-title":"Hyponatremia is associated with poor outcome in COVID-19","volume":"34","author":"Letellier","year":"2021","journal-title":"J. Nephrol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e565","DOI":"10.1002\/hsr2.565","article-title":"Hyponatremia in COVID-19 patients: Experience from Bangladesh","volume":"5","author":"Islam","year":"2022","journal-title":"Health Sci. Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1007\/s40618-022-01877-5","article-title":"Electrolyte imbalances as poor prognostic markers in COVID-19: A systemic review and meta-analysis","volume":"46","author":"Song","year":"2022","journal-title":"J. Endocrinol. Investig."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1135","DOI":"10.1093\/ndt\/gfab067","article-title":"Prevalence and outcomes of hyponatremia and hypernatremia in patients hospitalized with COVID-19","volume":"36","author":"Hirsch","year":"2021","journal-title":"Nephrol. Dial. Transpl."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1323","DOI":"10.34067\/KID.0001062022","article-title":"Associations of Dysnatremia with COVID-19 Status and Mortality","volume":"3","author":"Liu","year":"2022","journal-title":"Kidney360"},{"key":"ref_15","first-page":"100297","article-title":"Risk of severe clinical outcomes among persons with SARS-CoV-2 infection with differing levels of vaccination during widespread Omicron (B.1.1.529) and Delta (B.1.617.2) variant circulation in Northern California: A retrospective cohort study","volume":"12","author":"Skarbinski","year":"2022","journal-title":"Lancet Reg. Health Am."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"o980","DOI":"10.1136\/bmj.o980","article-title":"When Hong Kong\u2019s \u201cdynamic zero\u201d covid-19 strategy met omicron, low vaccination rates sent deaths soaring","volume":"377","author":"Ma","year":"2022","journal-title":"BMJ"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3618","DOI":"10.1038\/s41467-022-31395-0","article-title":"Contribution of low population immunity to the severe Omicron BA.2 outbreak in Hong Kong","volume":"13","author":"Chen","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1136\/gutjnl-2017-314605","article-title":"Long-term proton pump inhibitors and risk of gastric cancer development after treatment for Helicobacter pylori: A population-based study","volume":"67","author":"Cheung","year":"2018","journal-title":"Gut"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1979","DOI":"10.1136\/gutjnl-2018-317714","article-title":"Statins reduce the progression of non-advanced adenomas to colorectal cancer: A postcolonoscopy study in 187 897 patients","volume":"68","author":"Cheung","year":"2019","journal-title":"Gut"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2103","DOI":"10.1016\/j.dsx.2020.10.022","article-title":"Charlson comorbidity index and a composite of poor outcomes in COVID-19 patients: A systematic review and meta-analysis","volume":"14","author":"Henrina","year":"2020","journal-title":"Diabetes Metab. Syndr."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1093\/cid\/ciaa1119","article-title":"Unique Clusters of Severe Acute Respiratory Syndrome Coronavirus 2 Causing a Large Coronavirus Disease 2019 Outbreak in Hong Kong","volume":"73","author":"To","year":"2021","journal-title":"Clin. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"100130","DOI":"10.1016\/j.lanwpc.2021.100130","article-title":"Phylogenomic analysis of COVID-19 summer and winter outbreaks in Hong Kong: An observational study","volume":"10","author":"Chan","year":"2021","journal-title":"Lancet Reg. Health West Pac."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Kwok, W.C., Wong, C.K., Ma, T.F., Ho, K.W., Fan, L.W., Chan, K.F., Chan, S.S., Tam, T.C., and Ho, P.L. (2021). Modelling the impact of travel restrictions on COVID-19 cases in Hong Kong in early 2020. BMC Public Health, 21.","DOI":"10.1186\/s12889-021-11889-0"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1186\/s40635-021-00399-3","article-title":"Induced hypernatremia in patients with moderate-to-severe ARDS: A randomized controlled study","volume":"9","author":"Bihari","year":"2021","journal-title":"Intensive Care Med. Exp."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.resp.2016.03.002","article-title":"Induced hypernatraemia is protective in acute lung injury","volume":"227","author":"Bihari","year":"2016","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1541","DOI":"10.1172\/JCI18370","article-title":"Hyperosmolarity enhances the lung capillary barrier","volume":"112","author":"Safdar","year":"2003","journal-title":"J. Clin. Investig."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"13342","DOI":"10.1074\/jbc.M209922200","article-title":"Endothelial barrier strengthening by activation of focal adhesion kinase","volume":"278","author":"Quadri","year":"2003","journal-title":"J. Biol. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1164\/rccm.200501-005OC","article-title":"Inhibition of acid-induced lung injury by hyperosmolar sucrose in rats","volume":"172","author":"Safdar","year":"2005","journal-title":"Am. J. Respir Crit. Care Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1817","DOI":"10.1007\/s11255-015-1103-0","article-title":"Hypervolemic hypernatremia is the most common type of hypernatremia in the intensive care unit","volume":"47","author":"Sarahian","year":"2015","journal-title":"Int. Urol. Nephrol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"800","DOI":"10.1016\/j.ajem.2014.03.049","article-title":"Significance of hypernatremia following the correction of severe hyperglycemia","volume":"32","author":"Yanagawa","year":"2014","journal-title":"Am. J. Emerg. Med."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/3\/1042\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:18:58Z","timestamp":1760120338000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/3\/1042"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,29]]},"references-count":30,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["jcm12031042"],"URL":"https:\/\/doi.org\/10.3390\/jcm12031042","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,29]]}}}