Recent studies have highlighted the relationship between biomarkers and overactive bladder (OAB). Detrusor overactivity has been linked to increased Adenosine Triphosphate (ATP) secretion from urothelium and cholinergic nerve endings. This study aimed to evaluate urinary ATP as a diagnostic and follow-up biomarker for children with OAB, previously studied only in adults and children with neurogenic bladders.

Fifty-eight children with OAB and 28 healthy controls were prospectively included. Two midstream urine samples were collected from the OAB group: one pre-treatment and one at the first month of anticholinergic treatment. Urine samples were centrifuged, stored at -80°C, and ATP levels were measured via ELISA. Comparisons were made between the groups and pre-/post-treatment ATP levels in the OAB group. Correlation analysis was conducted between ATP levels and lower urinary system (LUS) parameters.

Of the OAB group, 29 (50%) were male, with a median age of 7 years (5–15), compared to 10 years (5–16) in controls. Median urinary ATP was significantly higher in the OAB group [12.15 (2.48–170.62) ng/mg Cr] than in controls [9.92 (3.09–29.95); p=0.04]. No significant difference was found between pre- and post-treatment ATP levels in the OAB group (p=0.84), nor was there a correlation between ATP levels and LUS parameters.

This prospective trial is the first to document that urinary ATP levels are higher in children with OAB. Consequently, urinary ATP could serve as a diagnostic biomarker for OAB in children.

In conclusion, this prospective study is the first in the literature to statistically demonstrate that urinary ATP can be a potential biomarker for diagnosing OAB in children. However, we believe that more comprehensive future studies involving patients suitable for urodynamic evaluation are needed to enable more detailed subgroup analyses. Additionally, further research with large-scale prospective studies is required to evaluate the effectiveness of ATP in predicting treatment success, particularly for patients with different symptom profiles, such as refractory OAB cases.