Comparison of Voiding Dysfunction Phenotypes in Women with Interstitial Cystitis/Bladder Pain and Myofascial Pelvic Pain: Results from the ICEPAC Trial.

OBJECTIVES: To evaluate whether voiding parameters differ in patients with the common overlapping pelvic pain disorders, interstitial cystitis/bladder pain syndrome (IC/BPS) and myofascial pelvic pain (MPP).

METHODS: Uroflow and voiding diary assessed voiding phenotypes in this prospective cohort study (ICEPAC) of women comparing IC/BPS, IC/BPS +MPP, MPP, and healthy control (HC) subjects.

RESULTS: In 36 HC, 24 IC/BPS, 37 IC/BPS+MPP, and 14 MPP subjects, the voiding diary measurements indicate lower voided volumes in IC/BPS and IC/BPS+MPP groups (185±24 mL, 169±20 mL, respectively) compared to HC and MPP groups (294 ±24 mL, 226 ±36 mL, respectively; p<0.05, p<0.05), as well as higher 24 hour voiding frequency (11.6 ±0.8 and 11 ±1.2 voids/24hrs, respectively; HC 7.1 ±0.5 voids/24hrs; p<0.05, p<0.05; MPP group 9 ± 1.2 voids/24hrs; p<0.05, p<0.05). Uroflow showed higher HC average flow rate (12.87±0.92) compared to IC/BPS, IC/BPS+MPP, and MPP (8.31±1.20, 8.02±0.80, 8.17±1.38, respectively; p<0.01, p<0.01, p<0.05) and peak flow rate (27.0±1.83) and IC/BPS, IC/BPS+MPP and MPP (16.20±2.2, 17.33±1.64, 17.21±2.69 respectively; p<0.01, p<0.01, p<0.05).

CONCLUSION: This quantitative evaluation of voiding diary and uroflow metrics reveals distinct voiding phenotypes, which can aid in the diagnosis of chronic pelvic pain syndromes. Patients with IC/BPS had more pain with a full bladder despite similar overall pain scores. Peak and average flow rates do not provide any differentiating power between IC/BPS and MPP patients. A longer time to peak flow may favor MPP though this finding needs confirmation.