Activities of Stress Axes in Female and Male Patients with Urge Incontinence

Background/Objectives: Urge incontinence (UI) is a condition defined as the involuntary loss of urine, affecting both women and men. The underlying pathophysiology is not completely understood, but it might involve the functioning of the autonomic nervous system (ANS) and the hypothalamic–pituitary–adrenal (HPA) axis, i.e., two main stress axes of the body. Therefore, the present study aimed to investigate the association of ANS and HPA axis activities with urge incontinence in female and male genders. Methods: For this purpose, four groups were established: (i) female patients with UI (n = 57), (ii) female control participants (n = 56), (iii) male patients with UI (n = 57), and (iv) male control participants (n = 57). ANS activity was assessed by heart rate variability (HRV) derived from a 5-min electrocardiogram (ECG) recording, and HPA activity was evaluated by salivary cortisol levels. HRV parameters consisted of both time- and frequency-domain parameters, notably the low frequency/high frequency (LF/HF) ratio, which is commonly interpreted as an index of sympathovagal balance. Results: Body mass index and age were higher in UI patients (p < 0.001). Cortisol levels did not differ significantly between groups (p > 0.05), whereas frequency-domain parameters of HRV (including LF/HF) were significantly lower in patient groups (p < 0.05). Conclusions: The data suggest that incontinence might be associated with altered ANS activity, with no effect on HPA axis dysregulation. Decreased LF/HF might be associated with a decreased sympathetic urine retention mechanism with increasing age in UI patients. Moreover, the data also suggest that cardiac autonomic control (assessed by HRV) might be a sensitive, non-invasive, and cost-effective tool for studying autonomic control of bladder function.