Evidence map›Paper›PMID 41931204›Full record

ArticleClinical and experimental nephrology2026

Correlation and dissociation factors between ionized, total, and corrected calcium in patients undergoing hemodialysis.

Chiharu Aizawa, Akio Nakashima, Kazuhiko Kato, Arisa Kobayashi, Rena Kawai, Yuriko Shibata, Saya Tanimoto, Keita Kimura, Ichiro Ohkido, Takashi Yokoo

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Article in Clinical and experimental nephrology, 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

10 authors.

Chiharu AizawaDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Akio NakashimaDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan. a-nakashima@jikei.ac.jp.ORCID http://orcid.org/0000-0002-3730-0301
Kazuhiko KatoDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Arisa KobayashiDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Rena KawaiDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Yuriko ShibataDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Saya TanimotoDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Keita KimuraShinkashiwa Clinic, Chiba, Japan.
Ichiro OhkidoDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
Takashi YokooDivision of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIonized calcium (iCa) has physiological activity in the body; however, the direct measurement of iCa is technically limited. Although total serum calcium (tCa) and corrected serum calcium (cCa) using the Payne correction formula have been used to assess calcium levels, their limitations have been noted. We aimed to clarify the degree of correlation and dissociation among iCa, tCa, and cCa levels in patients undergoing hemodialysis.

methodsThis cross-sectional study assessed the correlation between iCa, tCa, and cCa levels in patients undergoing hemodialysis. Factors involved in the correlation between iCa and tCa levels were evaluated using multiple regression analysis. Based on these results, we proposed a novel iCa prediction equation.

resultsTwo hundred and thirteen patients were enrolled. The median patient age was 65 (standard deviation, 10.2) years, and 68.2% of patients were male. The correlation coefficients were 0.867 for iCa and tCa and 0.854 for iCa and cCa. Correlations were also observed when albumin concentrations and pH were divided, both of which are known correlation factors. In multiple regression analysis of the relationship between tCa and iCa, sex, pH, albumin, phosphate, and magnesium levels were significant factors. We established a new corrected calcium equation using age and albumin level: (mg/dL) = 0.828 × total calcium - 0.314 × albumin (g/dL) + 0.007 × age + 2.922.

conclusionsiCa, tCa, and cCa had a correlation in patients undergoing hemodialysis, with a stronger correlation with tCa in iCa assessments.

Indexed as

CalciumRenal DialysisRenal Insufficiency, ChronicAgedBiomarkersCationsCross-Sectional StudiesFemaleHumansHypocalcemiaMagnesiumMaleMiddle AgedPhosphatesRegression AnalysisSerum Albumin, HumanBiomarkersCalciumCationsMagnesiumPhosphatesSerum Albumin, HumanCorrected calciumHemodialysisIonized calciumTotal calcium

Identifiers

PMID41931204

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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.