Circulating and Urinary Creatine Levels in the All of Us Research Program

BRIEF COMMUNICATION
David Nedeljkovic, Sergej M. Ostojic

 
For citation: Nedeljkovic D, Ostojic SM. Circulating and Urinary Creatine Levels in the All of Us Research Program. International Journal of Biomedicine. 2026;16(2):281-283. doi:10.21103/Article16(2)_BC
 
Originally published June 5, 2026

Abstract: 

Creatine is central to human bioenergetics, yet circulating creatine remains largely uncharacterized in population settings. Using data from the All of Us Research Program, we examined serum/plasma and urinary creatine in a demographically diverse U.S. cohort. We identified 246 adults with 1,576 serum or plasma creatine measurements and harmonized values across assay formats. Participant-level mean serum creatine was right-skewed in the full cohort but clustered tightly after exclusion of individuals with kidney disease. In adults without renal pathology (n=139), circulating creatine occupied a narrow physiological range (mean 0.94 mg/dL; median 0.90 mg/dL; interquartile range 0.76-1.10 mg/dL), indicating strong homeostatic regulation. In contrast, urinary creatine, assessed in 2,044 participants, displayed wide interindividual variability with a long upper tail. These findings establish the first population-scale reference framework for creatine in blood and urine and define ~ 1mg/dL as a pragmatic physiological anchor for circulating creatine in adults without kidney disease.

Keywords: 
creatine • bioenergetics • population • kidney disease
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Received January 27, 2026.
Accepted March 9, 2026.
© 2026 The Author(s). International Journal of Biomedicine is published by IMRDC.
This is an open access article under the CC BY-NC-ND 4.0 license.