The Relation between Autonomic Nervous System Activity and Lower Urinary Tract Symptoms: An Analysis of Heart Rate Variability in Men with Lower Urinary Tract Symptoms

Abstract

Purpose: Lower urinary tract symptoms (LUTS) are common, but their etiology and mechanism are still unclear. We believe that changes in autonomic nervous system (ANS) activity may be contributory, because the lower urinary tract is regulated through the sympathetic and parasympathetic nervous systems. Heart rate variability (HRV) is a tool by which autonomic nervous function can be measured, and therefore we measured and compared parameters of heart rate variability between men with LUTS and healthy subjects. Materials and Methods: Thirty-nine men with LUTS [mean age 56.9±8.9 years old, International Prostate Symptom Score (IPSS)≥8] and 23 healthy men (mean age 57.0±1.8 years old, IPSS＜8) were included in the present study. HRV is known to be a useful tool for evaluating ANS activity, and we measured and compared HRV in the resting state. Results: The standard deviation of the N-N interval (SDNN) and total power (TP) for patients with LUTS revealed no significant differences from those in the control group. On frequency domain analysis, there was evidence of decreased high frequency (HF) in patients with LUTS (p＜ 0.05), but there were no significant differences in other parameters such as heart rate, square root of the mean squared differences of successive N-N intervals (RMSSD), very low frequency (VLF), low frequency (LF), or the LF/HF ratio. Conclusions: Patients with LUTS exhibited different HRV parameters compared with normal controls. Their decreased HF indicated that they may have had some kind of disease or imbalance in the autonomic nervous system, which may distinguish patients with LUTS from healthy men.