This study aims to better understand the pathways leading to pain in women with two types of pelvic pain condition (endometriosis-associated pain and bladder pain syndrome) and determine whether these pathways can be used to subgroup patients.
Chronic pelvic pain is as common as asthma, migraine and back pain and has a very significant impact on quality of life. However, it is still poorly understood and the available treatments are limited and often not successful. This project focuses on two causes of chronic pelvic pain: endometriosis and interstitial cystitis/bladder pain syndrome. Endometriosis (the presence of tissue resembling the lining of the womb outside of the womb) is very common, affecting \~1 in 10 women, and is associated with often disabling pelvic pain symptoms including painful periods, pain throughout the month, and pain associated with sex, passing urine and opening bowels. Interstitial cystitis/bladder pain syndrome is much less common but dramatically reduces quality of life with many women planning their day around trips to the toilet. This multi-centre study will be carried out at 3 sites in Europe and 1 in the U.S.. Rather than focusing on the pelvis, the investigators will approach these conditions in the context of other chronic pain conditions with which they share many features and thus consider the many different systems that might contribute to generating and maintaining pain. The investigators will combine detailed clinical and questionnaire data with tests of the function of a variety of systems (including nerve function, stress response and psychology) and the results of analyses of different body fluids and tissues (including blood, urine, endometriosis lesions). No study treatment or intervention will be given during TRiPP. The aim is to identify pathways responsible for pain in these women and determine whether they can be divided into subgroups on the basis of different pain pathways that might therefore respond to different treatments. Ultimately the investigators hope to identify new targets for treatment and contribute to the design of more personalised treatment plans.
Study Type
OBSERVATIONAL
Enrollment
787
IBMC
Porto, Portugal
University of Oxford
Oxford, Oxfordshire, United Kingdom
Quantitative Sensory Testing (QST)
QST of the dorsal of the foot and midline lower abdomen according to the German Neuropathic Pain Network Protocol.
Time frame: 1 year
Presence of abdominal wall muscle tenderness
Assessment of the abdominal wall specifically looking for muscle tenderness according to a standardised protocol (an enhanced Carnetts test as described by Scheltinga and Roumen 2017). Subjects will be categorised into muscle tenderness present or absent.
Time frame: 1 year
Change of pressure pain threshold (PPT)
A standardised conditioned pain modulation (CPM) paradigm will be used to investigate the change in pressure pain threshold on the dorsum of the foot. An ischaemic stimulus to the contralateral arm will be used as the conditioned stimulus. The foot PPT will be measured before the conditioned stimulus and immediately after. The change will be reported as the (PPTbefore - PPTafter).
Time frame: 1 year
Area under the curve (AUC) of single day salivary cortisol profile
Saliva will be collected at home at the specified times allowing a daily AUC of salivary cortisol for each subject to be calculated. Collection times: waking; 30-45 minutes after waking; before lunch; before dinner; bedtime.
Time frame: 1 year
Change in salivary cortisol
A saliva sample will be collected at rest immediately before the CPM paradigm described in outcome 3 and then again immediately after. The ischaemic pain stimulus used as the conditioning stimulus in this paradigm is the most noxious component of the physiological testing paradigms used in this study and therefore the most likely to generate a stress response. The change will be reported as Cortisol(before)-Cortisol(after).
Time frame: Saliva collected immediately before and immediately after CPM paradigm (outcome 3).
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Heart rate (HR)
Assessed over a 20 minute period at rest.
Time frame: 1 year
Change in heart rate
Assessed at rest immediately before the CPM paradigm described in outcome 3 and then again immediately after. The ischaemic pain stimulus used as the conditioning stimulus in this paradigm is the most noxious component of the physiological testing paradigms used in this study and therefore the most likely to generate a stress response. The change will be reported as HR(before) - HR(after).
Time frame: HR assessed immediately before and immediately after the CPM paradigm (outcome 3)
Blood pressure (BP)
Assessed over a 20 minute period at rest. Measured in mmHG.
Time frame: 1 year
Change in Blood pressure
Assessed at rest immediately before the CPM paradigm described in outcome 3 and then again immediately after. The ischaemic pain stimulus used as the conditioning stimulus in this paradigm is the most noxious component of the physiological testing paradigms used in this study and therefore the most likely to generate a stress response. The change will be reported as BP(before) - BP(after).
Time frame: BP assessed immediately before and immediately after the CPM paradigm (outcome 3)
Bladder sensitivity to filling
Assessed with standardised non-invasive bladder filling paradigm, measured as time to verbal reports of different sensations of bladder fullness (first sensation, first urge) and then need to void (maximum tolerance) after drinking 600 ml water. Subjects will be categorised into those with bladder sensitivity compared to published norms for reproductive age women and those with normal bladder sensation.
Time frame: 1 year
Volume voided at maximum tolerance
Assessed with standardised non-invasive bladder filling paradigm described in outcome 10. The volume of urine voided when maximum tolerance is reached will be measured in mls.
Time frame: 1 year
fMRI scan
fMRI scan with response to punctate stimuli of midline lower abdomen.
Time frame: 1 year
Pain Catastrophising: Pain Catastrophising Scale (PCS) (Sullivan)
Measured with the Pain Catastrophising Scale (Sullivan). Scores range from 0 - 52 with high scores representing higher levels of pain catastrophising. Although three sub scales exist they will not be assessed for the purposes of these main analyses.
Time frame: Baseline
Comorbid psychological distress
Measured with the Hospital Anxiety and Depression Scale (HADS). Scores range from 0 - 21 for each of the two sub scales measuring anxiety and depression. The two sub scales will be summed as a unidimensional measure of psychological distress in initial analyses (0 - 42 with higher scores representing greater distress).
Time frame: Baseline
Metabolomic data
Discovery study of levels of all known metabolite in plasma using an established validated proprietary tool designed by Metabolon (https://www.metabolon.com).
Time frame: Baseline
Proteomic data
Study measuring levels of proteins detected on two panels (inflammation and neurological) as designed by OLink (https://www.olink.com).
Time frame: Baseline
Transcriptomic data
Discovery transcriptomic analysis of matched eutopic and ectopic endometrium from endometriosis and control women will be performed on a subgroup of participants. Both descriptive data and pathway analysis will be performed.
Time frame: Baseline
Comorbidities
Assessed with the complex medical symptoms inventory (CMSI). The CMSI contains a 41 item symptom screener, which an increasing score on adds up to a higher functional somatic burden (scores range from 0-41). Additionally, clusters of symptoms point to specific diagnoses for which the full diagnostic criteria questions are provided allowing the commonest overlapping pain conditions to be screened for: Fibromyalgia temporomandibular disorders irritable bowel syndrome chronic tension type headache migraine chronic low back pain myalgic encephalitis/chronic fatigue syndrome interstitial cystitis/painful bladder syndrome endometriosis vulvodynia
Time frame: Baseline
Past trauma
Assessed with the Childhood Traumatic Events Scale (CTES). Scores range from 0 - 42 with higher scores representing more experience of early trauma. No sub scales will be derived.
Time frame: Baseline
Recent trauma
Assessed with the Recent Traumatic Events Scale (RTES). Scores range from 0 - 42 with higher scores representing more experience of recent trauma. No sub scales will be derived.
Time frame: Baseline