PURPOSE: Interstitial cystitis/bladder pain syndrome (IC/BPS) and myofascial pelvic pain (MPP) are frequently comorbid chronic pelvic pain disorders.
Differences in bladder function between IC/BPS and MPP suggest that efferent autonomic function may differentiate these syndromes. Heart rate variability (HRV), defined as the difference in duration of successive heartbeats, serves as an index of autonomic function by measuring its ability to modify heart rate in response to neurophysiological changes. High frequency HRV (HF-HRV) was used as a reflection of more rapid vagally mediated (parasympathetic) changes, while low frequency HRV (LF-HRV) signified slower fluctuations related to baroreflex and sympathetic outflow.
MATERIALS AND METHODS: HRV was derived by autoregressive frequency analysis of the continuous ECG recording of heart rate (HR) while supine (10 minutes), tilted 70° head up (30 minutes), and supine again (10 minutes). This IRB-approved study included 105 female subjects (32 healthy, 26 IC/BPS, 12 MPP, and 35 IC/BPS+MPP).
RESULTS: In all positions, healthy controls had higher HF-HRV than women with IC/BPS and IC/BPS+MPP. MPP subjects were similar to control with higher HF-HRV at baseline (supine 1) and upright positions than IC/BPS subjects. Differences in LF-HRV were less evident while LF/HF ratio differences appeared to be driven by the HF-HRV component.
CONCLUSION: IC/BPS subjects had diminished vagal activity and a shift towards sympathetic nervous system dominance. Overall, these data support the hypothesis that changes in autonomic function occur in IC/BPS, but not MPP. These changes may result from the presence of IC/BPS or contribute to its pathophysiology through abnormal self-regulatory function.
Written by:
Williams DP, Chelimsky G, McCabe NP, Koenig J, Singh P, Janata J, Thayer JF, Buffington CA, Chelimsky T. Are you the author?
The Ohio State University; Medical College of Wisconsin; Case Western Reserve University School of Medicine.
Reference: J Urol. 2015 May 8. pii: S0022-5347(15)03909-9.
doi: 10.1016/j.juro.2015.04.101
PubMed Abstract
PMID: 25963185