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Sex differences dominate urinary extracellular DNA concentrations and variability in humans and rodents

Year: 2026

Type: article

Abstract: Urinary extracellular DNA has emerged as a promising non-invasive biomarker for kidney and urinary tract diseases. However, its physiological concentration, variability, and potential sex-dependent differences in healthy individuals are poorly defined. This lack of baseline knowledge limits the clinical and translational use of urinary extracellular DNA. Morning urine samples were collected from 66 healthy adults (33 women and 33 men), as well as from female and male mice and rats. Extracellular DNA was isolated from urine supernatant and quantified fluorometrically. Nuclear and mitochondrial DNA were measured using quantitative polymerase chain reaction. Urinary creatinine, osmolality, and deoxyribonuclease activity were assessed to evaluate potential confounding factors. Fragment size distribution was analysed using capillary electrophoresis. Sex differences were analysed using unpaired statistical tests, variability was assessed by comparing variances and coefficients of variation, and correlations were evaluated using Pearson analysis. Women exhibited approximately 5-fold higher concentrations of urinary extracellular DNA than men and showed markedly greater inter-individual variability. These differences persisted after normalization to creatinine and osmolality and were significant for nuclear DNA but not mitochondrial DNA. Female mice and rats also demonstrated higher extracellular DNA concentrations than males, with approximately 2-fold higher levels in mice and 11-fold higher levels in rats. No association was found between extracellular DNA concentration and urine concentration parameters, menstrual cycle phase, or urinary deoxyribonuclease activity. Most urinary extracellular DNA consisted of nucleosome-sized fragments. Biological sex is a major determinant of urinary extracellular DNA concentration and variability in humans and rodents. The high physiological variability, particularly in females, limits the use of absolute urinary extracellular DNA levels as a standalone biomarker. These findings underscore the necessity of incorporating sex-specific considerations into the design, analysis, and interpretation of urinary extracellular DNA studies.

Source: Scientific Reports

DOI: 10.1038/s41598-026-76406-y