@article{Andjelic2026, 
author = {Bogdan Andjelic and Tijana Lainovic and Nikola Todorovic and Jovana Panic and Milan Vranes and Valdemar Stajer and Sergej M. Ostojic},
title = {Exercise affects salivary biomarkers of creatine metabolism in healthy adults},
year = {2026},
journal = {Sports Medicine and Health Science},
volume = {8},
number = {2},
pages = {193-196},
keywords = {Creatine metabolism, Exercise, Saliva, Serum},
url = {https://www.sciopen.com/article/10.1016/j.smhs.2025.03.010},
doi = {10.1016/j.smhs.2025.03.010},
abstract = {BackgroundWe monitored changes in salivary creatine pre- and post-high-intensity exercise in young adults while also investigating the potential correlation between salivary and serum creatine levels.MethodSaliva and serum samples were collected before and immediately after an incremental running-to-exhaustion treadmill test in fifteen young adults (mean age [23.9 ​± ​2.9] years, eight females), with samples analyzed for guanidinoacetic acid, creatine, and creatinine using a liquid chromatography–tandem mass spectrometry method.ResultsFollowing exercise, there was a substantial elevation in salivary creatine levels from (17.5 ​± ​14.2) μmol·L−1 to (43.6 ​± ​30.4) μmol·L−1 (p ​< ​0.001), coupled with a significant increase in salivary creatinine from (11.3 ​± ​5.8) μmol·L−1 to (17.0 ​± ​9.3) μmol·L−1 (p ​= ​0.04). In contrast, serum creatine levels were unaffected by exercise (p ​= ​0.80), while creatinine levels exhibited a strong tendency to decrease post-exercise (from [81.8 ​± ​17.5] μmol·L−1 to [73.1 ​± ​11.6] μmol·L−1; p ​= ​0.06). A comparison of the slopes of the two regression lines (saliva vs. serum) revealed significant differences for both creatine (p ​= ​0.01) and creatinine (p ​= ​0.03).ConclusionsThe above findings suggest a potential difference in the dynamics of creatine metabolites in these two bodily fluids, both pre and post-exercise.}
}