Endometriosis
Conditions
Keywords
endometriosis, cryotherapy, inflammation, pain, chronic pelvic pain, endometriosis-associated pain
Brief summary
The aim of this study is to investigate whether whole-body cryotherapy (a brief exposure to very cold temperatures) can help reduce pain and improve quality of life in people living with endometriosis, and whether it may represent a safe, non-pharmacological approach to managing endometriosis-related symptoms. Up to 30 participants with symptomatic endometriosis (chronic pelvic pain for more than six months) will be recruited over a 12-month period. Participants will attend two study visits at the hospital, approximately four weeks apart. Between these visits, participants will undergo five whole-body cryotherapy sessions, each lasting approximately 3 minutes. During cryotherapy, participants stand in a specialised chamber where the body is briefly exposed to cold, dry air (around -120°C). During the study, will be assessed changes in systemic inflammation and biological markers using blood, saliva, urine, vaginal, and stool samples. Data will be collected using questionnaires evaluating pain and related symptoms, quality of life, sleep, fatigue, intestinal symptoms, and overall wellbeing. The active study phase lasts approximately 4-6 weeks. A final follow-up assessment at 15 weeks will be conducted remotely using questionnaires and self-collected samples.
Detailed description
Endometriosis is a chronic inflammatory and estrogen-dependent condition characterized by the presence of endometrial-like tissue outside the uterus, commonly associated with persistent pelvic pain, reduced quality of life, and significant long-term morbidity. Despite available hormonal and surgical treatments, a substantial proportion of individuals continue to experience chronic pain, highlighting an unmet need for novel therapeutic approaches. Current treatment strategies do not fully address the underlying inflammatory, neurovascular, and nociceptive mechanisms that contribute to pain persistence and central sensitization in endometriosis. Whole-body cryotherapy (WBCT) is a non-pharmacological intervention involving brief exposure to extremely low temperatures, which has been associated with anti-inflammatory, analgesic, and neuromodulatory effects in other chronic conditions. Proposed mechanisms include modulation of systemic inflammatory pathways, reduction of oxidative stress, and effects on central pain processing. However, the potential role of WBC in the management of endometriosis-associated pain has not yet been established. This study is a single-site, single-arm interventional pilot study designed to evaluate the feasibility, safety, acceptability, and preliminary efficacy of a structured WBCT intervention in individuals with symptomatic endometriosis. In addition to clinical outcomes, the study aims to explore biological mechanisms underlying potential treatment effects through the assessment of systemic inflammatory and other biomarkers. Participants will undergo a standardized course of WBCT sessions over a two-week period, with repeated clinical and biological assessments conducted at predefined timepoints. Clinical outcomes will include patient-reported measures of pain, quality of life, fatigue, sleep, and other symptom domains, as well as analgesic use and global impression of change. Feasibility outcomes will include recruitment rates, retention, and participant acceptability of the intervention and study procedures. Biological assessments will include the collection of blood (venous and capillary), saliva, urine, vaginal, and stool samples to evaluate markers of systemic inflammation, stress, and gut health. Samples will be collected at baseline, during the intervention period, and at follow-up, enabling exploration of temporal changes associated with WBC exposure. Study visits will be conducted at baseline and post-intervention, with an additional remote follow-up evaluation. The intervention phase includes multiple WBC sessions delivered at a dedicated facility, with complementary data collection performed both in-clinic and through self-collected samples. The findings from this exploratory study will provide preliminary evidence on the clinical and biological effects of WBCT in endometriosis, inform the feasibility of larger controlled trials, and contribute to understanding whether WBCT may represent a novel non-pharmacological approach targeting inflammatory and nociceptive pathways in endometriosis-associated pain.
Interventions
PROCEDUREWhole-Body Cryotherapy
Whole-body cryotherapy is a non-pharmacological intervention involving brief exposure of the body to extremely cold, dry air (typically around -110°C to -140°C) in a specialised cryotherapy chamber. Each session lasts approximately 2-3 minutes and is conducted under controlled conditions. The intervention is designed to induce physiological responses including vasoconstriction, modulation of inflammatory pathways, and potential analgesic effects.
Sponsors
University of Edinburgh
NHS Lothian
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
16 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Women or assigned female at birth * Aged 16 or over * Endometriosis identified at laparoscopy or imaging, performed within the last ten years * Chronic pelvic pain for more than six months * Willing to comply with the treatment * Willing to use effective contraception throughout the trial (if needed) * Willing and able to give informed consent
Exclusion criteria
* Pregnant, breastfeeding or actively trying to get pregnant * Post-menopausal (no periods for \>12 months and not taking hormonal treatments to prevent periods, or bilateral oophorectomy performed) * Previous hysterectomy with bilateral oophorectomy * Raynaud's Disease * Current treatment for malignancy * Diabetes * Known hypothyroidism * Pre-existing or current diagnosis of anaemia * Cardiovascular disease: severe hypertension (180/100, unstable angina, arrhythmia, recent (\<6months) myocardial infarction, peripheral artery disease, cardiac pacemaker, recent (\<6months) stroke or transient ischaemic attack) * Acute kidney and urinary tract diseases * Cryoglobulinemia * Previous venous thromboembolism or peripheral artery occlusive disease * Cold urticaria * Livedo reticularis * Open wounds or ulcers, large-area bacterial and viral skin infections * Uncontrolled seizure disorder * Known coagulopathy (eg von Willibrand disease, haemophilia) * Severe claustrophobia * Acute infections and fever * Intoxication (alcohol, drugs) * Signs or symptoms of cold allergy * Severe wasting diseases * Known Hepatitis B/C and/or HIV (due to Royal Mail restrictions on biospecimen postage)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in average pain over the preceding week measured by an 11-point Numerical Rating Scale (NRS) | From baseline to 4 weeks post-intervention | The Numerical Rating Scale (NRS) ranges from 0 to 10, where 0 indicates no pain and 10 indicates the worst possible pain. Participants will rate their average pain over the preceding week at baseline and at 4 weeks following completion of the cryotherapy intervention. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in average pain over the preceding week measured by an 11-point Numerical Rating Scale (NRS) | From baseline to 15 weeks | The Numerical Rating Scale (NRS) ranges from 0 to 10, where 0 indicates no pain and 10 indicates the worst possible pain. Participants will rate their average pain over the preceding week at baseline and at 15 weeks. |
| Change in neuropathic pain assessed by the PainDETECT questionnaire (PD-Q) | From baseline to 4 weeks and 15 weeks | The PainDETECT questionnaire (PD-Q) is a validated 9-item screening tool used to assess neuropathic pain components. Scores range from -1 to 38, with higher scores indicating a higher likelihood of neuropathic pain. |
| Change in quality of life assessed by Endometriosis Health Profile (EHP-30) | From baseline to 4 weeks and 15 weeks | The Endometriosis Health Profile (EHP-30) questionnaire is a validated tool used to assess quality of life components over the previous four weeks. It includes 30 core questions (five scales: pain, control, emotions, social support, self-image) scoring 0-100, where higher scores indicate worse health. |
| Change in health-related quality of life assessed by EQ-5D-5L questionnaire | From baseline to 4 weeks and 15 weeks | The EQ-5D-5L questionnaire is a validated 5-level tool used to measure health-related quality of life, consisting of a descriptive system covering five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) and a vertical visual analogue scale (VAS) ranging from 0 (worst) to 100 (best). |
| Change in severity of fibromyalgia symptoms assessed by Fibromyalgia Impact questionnaire | From baseline to 4 weeks and 15 weeks | The Fibromyalgia Impact questionnaire is a validated tool used that measure the severity of fibromyalgia, its impact on daily life, and treatment progress. Scores range from 0 to 100, where higher scores indicate greater impairment. A score of 50 indicates an average patient, while over 70 indicates severe impairment. |
| Change in fatigue assessed by the Fatigue Severity Scale (FSS) | From baseline to 4 weeks and 15 weeks | The Fatigue Severity Scale (FSS) questionnaire is a 9-item self-report questionnaire designed to measure the severity of fatigue and its impact on daily functioning, particularly for chronic conditions. Respondents rate statements on a 7-point Likert scale (9-63), with higher scores (up to 63) indicating greater fatigue severity. |
| Change in sleep quality assessed by the Sleep Timing Questionnaire (STQ) | From baseline to 4 weeks and 15 weeks | The Sleep Timing Questionnaire (STQ) is a 18-item, self-report tool used to measure habitual bedtimes, wake times, sleep latency, and wake after sleep onset (like a sleep diary). |
| Change in analgesic use during the study period | From baseline to 4 weeks and 15 weeks | Participant-reported frequency and quantity of analgesic use. |
| Feasibility assessed by recruitment and retention rates | Frome baseline to study end. Up to 12 months | Proportion of eligible participants enrolled and completing study follow-up |
| Patient satisfaction assessed by Patient Global Impression of Change (PGIC) questionnaire | At 4 weeks and 15 weeks | The Patient Global Impression of Change (PGIC) is a 7-point, self-reported scale used in clinical practice to evaluate a patient's overall perception of improvement following the intervention. Patients select one of the following to describe their change: 1. Very Much Improved 2. Much Improved 3. Minimally Improved 4. No Change 5. Minimally Worse 6. Much Worse 7. Very Much Worse |
| Acceptability of the intervention assessed by a study-specific questionnaire | At 4 weeks and 15 weeks | Overall acceptability will also be evaluated using a study-specific questionnaire assessing participant satisfaction (e.g. perceived effectiveness, and self-efficacy) with the intervention and study procedures. |
| Change in cognitive symptoms (brain fog) assessed by the Brain Fog Scale (BFS) | From baseline to 4 weeks and 15 weeks | The Brain Fog Scale (BFS) is a validated, self-report questionnaire designed to measure the severity of "brain fog" (cognitive difficulties such as memory impairment, lack of focus, and mental confusion and fatigue). It consists of 9 items rated on a 7-point Likert scale, with higher scores indicating greater symptom severity. |
| Change in gastrointestinal symptoms assessed by the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) | From baseline to 4 weeks and 15 weeks | The IBS Symptom Severity Scale (IBS-SSS) is a 5-item, 500-point questionnaire used to measure the intensity of Irritable Bowel Syndrome symptoms over the past 10 days. It evaluates pain severity/frequency, bloating, bowel habit dissatisfaction, and quality of life, categorizing IBS as "no symptoms" (\<75), "mild" (75-174), "moderate" (175-299), or severe (300-500). |
| Change in systemic inflammatory markers with cortisol concentration | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes serum and salivary cortisol measured in blood and saliva samples, reported in µg/dL (or nmol/L) |
| Change in salivary alpha-amylase activity | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes salivary alpha-amylase measured in saliva samples, reported in U/mL |
| Change in systemic inflammatory markers with C-reactive protein (CRP) concentration | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes serum C-reactive protein (CRP) levels in blood samples, reported in mg/L. |
| Change in systemic inflammatory markers with inflammatory cytokine concentrations | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes inflammatory cytokines (e.g., IL-6, TNF-α, IL-1β) measured in serum/plasma samples, reported in pg/mL. |
| Change in bowel inflammatory markers with faecal calprotectin concentration | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes faecal calprotectin measured in stool samples, reported in µg/g. |
| Change in gut microbiome composition | From baseline to 4 weeks after cryotherapy sessions and 15 weeks | Includes gut microbiome composition assessed in stool samples. |
Countries
United Kingdom
Outcome results
None listed