Effects of urination process on heart rate variability.
Level 4 - case-series / case-control
Prospective within-subject physiological study without a separate comparison group.
PubMed 39543065 · doi:10.1007/s11255-024-04282-4
What was done
Electrocardiography was used to assess autonomic nervous system activity via heart rate variability (HRV) in 40 healthy male participants aged 18–30. Six sequential 90-second measurements were recorded in the sitting position: pre-urination on a chair, pre-urination on a toilet, during urination, post-urination on a toilet, post-urination on a chair, and basal post-urination on a chair. Measured metrics included heart rate (HR), SDNN, RMSSD, pNN50, total power (TP), VLF, LF, HF, and the LF/HF ratio.
What was found
The abstract reports directional shifts with significance levels but provides no exact numerical values, effect sizes, or confidence intervals. HR, SDNN, TP, LF, and LF/HF significantly increased during the urination process (P < 0.05). In contrast, RMSSD, pNN50, and HF were significantly elevated prior to urination while seated on the toilet compared to sitting on a chair before and after voiding (P < 0.05).
Why it matters
The findings demonstrate transient, phase-specific autonomic shifts during voiding, characterized by a rise in parasympathetic activity immediately prior to micturition followed by increased sympathovagal tone during voiding.
Limits
The abstract omits all baseline values, point estimates, and dispersion metrics. The sample is small (n = 40) and restricted exclusively to young, healthy males voiding in a seated position, preventing generalization to females, standing micturition, older demographics, or individuals with dysautonomia or lower urinary tract dysfunction. In addition, 90-second recording windows are very brief for standard frequency-domain HRV analyses.
Cited by
- context Urination induces vagal withdrawal, resulting in an elevation in heart rate.