Evidence map›Paper›PMID 42684431›Full record

ArticleZeitschrift fur Gerontologie und Geriatrie2026

Heat-associated hyponatremia and its outcomes in very old inpatients in northern Germany.

Naomi Mader, Stefan Muthers, Klaus Albrecht, Martin Scharpenberg, Andreas Kribben, Stefan Herget-Rosenthal

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Article in Zeitschrift fur Gerontologie und Geriatrie, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

6 authors.

Naomi MaderDepartment of Nephrology, University Duisburg-Essen, Duisburg-Essen, Germany. naomi.mader@stud.uni-due.de.
Stefan MuthersResearch Centre for Human Biometeorology, Deutscher Wetterdienst, Freiburg im Breisgau, Germany.
Klaus AlbrechtDepartment of Medicine, Rotes Kreuz Krankenhaus, Bremen, Germany.
Martin ScharpenbergCompetence Center for Clinical Trials-Biometry, University of Bremen, Bremen, Germany.
Andreas KribbenDepartment of Nephrology, University Duisburg-Essen, Duisburg-Essen, Germany.
Stefan Herget-RosenthalDepartment of Nephrology, University Duisburg-Essen, Duisburg-Essen, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHyponatremia is frequent in very old patients ≥ 80 years (VOP). Data for hyponatremia associated with moderate heat in VOP are scarce. We aimed to provide epidemiological data, to identify risk factors of hyponatremia and to present outcomes in VOP after hot and cold days in northern Germany.

methodsOf 22,085 VOP admitted unplanned to the departments of internal medicine and trauma surgery in 2011-2023, we studied those admitted 1-2 days after hot (N = 308) and cold days (N = 253) in June-August of these years (57.9% female, median age 86 years). Heat was defined as daily mean temperatures ≥ 95th (24.4 °C), cold as ≤ 5th percentile (12.3 °C) in June-August from 2011-2023. Primary outcome was hyponatremia on admission. Secondary outcomes were risk factors of hyponatremia and the frequency of major adverse hyponatremia events until day 30 (MAHE30, intensive care unit and/or long hospital stay, mortality and/or discharge to a care facility).

resultsIn 561 patients, hyponatremia occurred more often after hot than cold days (36.7% vs. 15.0%; P < 0.001). Hyponatremia was predominately mild, acute or acute on chronic and isotonic in patients admitted after both hot and cold days. Hyponatremia rates increased by 50% after 3 consecutive hot days. Heat was a strong risk factor of hyponatremia. In 151 hyponatremic patients, MAHE30 occurred more often after hot compared to cold days (55.6% vs. 31.6%; P = 0.008). Heat was identified as a strong risk factor also of MAHE30 in hyponatremic patients.

conclusionModerate heat in northern Germany is associated with an increased rate of hyponatremia and is a strong risk factor of hyponatremia in VOP. After hot days, hyponatremic VOP are at an increased risk for severe associated morbidity and mortality.

Indexed as

Heat Stress DisordersHot TemperatureHyponatremiaAged, 80 and overFemaleGermanyHospitalizationHumansLength of StayMaleRisk FactorsClimateElectrolyte disorderHeatOutcomeTemperature

Identifiers

PMID42684431
PMCPMC13597654

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.