Imperial College London
Alternate

ProfessorWaljitDhillo

Faculty of Medicine, Department of Metabolism, Digestion and Reproduction

Professor of Endocrinology & Metabolism
 
 
 
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Contact

 

+44 (0)20 7594 3487w.dhillo Website

 
 
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Assistant

 

Ms Suzanne Wheeler +44 (0)20 7594 3487

 
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Location

 

6N6ECommonwealth BuildingHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Phylactou:2023:10.3389/fendo.2023.1070443,
author = {Phylactou, M and Comninos, A and salih, A and labib, M and chia, eng P and Clarke, S and Moore, P and Tan, T and Cegla, J and Dhillo, W and Abbara, A},
doi = {10.3389/fendo.2023.1070443},
journal = {Frontiers in Endocrinology},
pages = {1--10},
title = {Derivation and comparison of formulae for the adjustment of total calcium},
url = {http://dx.doi.org/10.3389/fendo.2023.1070443},
volume = {14},
year = {2023}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Background: Free ionized calcium (Ca2+) is the biologically active component of total calcium (TCa) and hence responsible for its biological action. TCa is routinely adjusted for albumin using several formulae (e.g. James, Orell, Payne and Berry) to more closely reflect Ca2+. Here, we derive a novel formula to estimate Ca2+ and compare its performance to established formulae.Methods: Cohort for prediction of Ca2+: 2806 serum samples (TCa) taken contemporaneously with blood gas samples (Ca2+) at Imperial College Healthcare NHS Trust were used to derive formulae to estimate Ca2+ using multivariable linear regression. Cohort for prediction of PTH: Performance of novel and existing formulae to predict PTH in 5510 patients was determined by Spearman correlation.Results: Ca2+ prediction Cohort: Adjusted calcium (r2 = 0.269) was less strongly associated with Ca2+, than TCa (r2 = 0.314). Prediction of Ca2+ from a newly derived formula incorporating TCa, potassium, albumin, and hematocrit had an improved r2 of 0.327, whereas inclusion of all available parameters increased the r2 further to 0.364. Of the established formulae, James performed best in predicting Ca2+ (r2 = 0.27). PTH prediction cohort: Berry resulted in higher whereas Orell in lower adjusted calcium levels. Prediction of PTH was strongest in the setting of hypercalcemia, with James having the highest Spearman correlation coefficient (+0.496) similar to including all parameters (+0.499).Conclusion: Adjustment of calcium for albumin using established formulae does not always outperform unadjusted TCa in the reflection of Ca2+. Further prospective studies are needed to optimise adjustment of TCa and to establish bounds for validity.
AU  - Phylactou,M
AU  - Comninos,A
AU  - salih,A
AU  - labib,M
AU  - chia,eng P
AU  - Clarke,S
AU  - Moore,P
AU  - Tan,T
AU  - Cegla,J
AU  - Dhillo,W
AU  - Abbara,A
DO  - 10.3389/fendo.2023.1070443
EP  - 10
PY  - 2023///
SN  - 1664-2392
SP  - 1
TI  - Derivation and comparison of formulae for the adjustment of total calcium
T2  - Frontiers in Endocrinology
UR  - http://dx.doi.org/10.3389/fendo.2023.1070443
UR  - https://www.frontiersin.org/articles/10.3389/fendo.2023.1070443/full
UR  - http://hdl.handle.net/10044/1/104123
VL  - 14
ER  -
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