Pain in Endometriosis And the Relation to Lifestyle

The Numerical Rating Scale (NRS) ranges from 0 (no pain) to 10 (unbearable pain), and is the most commonly used subjective measure to assess pain intensity. Patients will score there estimated average pain intensity and there highest pain intensity of the previous 7 days.

Minimum value: 0 Maximum value: 10 Higher score indicates a higher level of pain intensity.

The Endometriosis Health Profile 30 (EHP-30) is a disease-specific QoL questionnaire which is validated for use in endometriosis patients and measures the impact of the disease on physical, mental and social aspects of life.

The EHP-30 is not a numerical scale.

The Short Form 36 (SF-36) is a multipurpose, general health survey which is applied to measure QoL on nine different domains: physical functioning, social functioning, role limitations due to physical health, role limitations due to emotional problems, emotional well-being, vitality, pain, general health, and health change.

The SF-36 is not a numerical scale.

High-dimensional flow cytometry will be done to analyse immune cells such as T cells, B cells, monocytes, and macrophages. Also Naturel Killer (NK) cells will be analysed. Also in the menstruum, markers for (cluster of differentiation 56) CD56, (cluster of differentiation antigen 16) CD16, (killer immunoglobulin receptors)) KIR and (natural cytotoxicity receptors) NCR, and activation markers such as CD69 will be characterised.

High-dimensional flow cytometry will be done to analyse immune cells such as T cells, B cells, monocytes, and macrophages. Also NK cells will be analysed. Previous studies have described a key role for NK cells in endometriosis. A decreased percentage of NK cells was observed in peritoneal fluid of endometriosis patients compared to HC (Hoogstad-vanEvert et al., 2018 ). For in depth NK cell characterisation we will include markers for CD56, CD16, KIR (killer immunoglobulin receptors) and NCR (natural cytotoxicity receptors), and activation markers such as CD69.

Analysed with the Olink Proteomics 96 inflammatory panel and Luminex multiplex assay for important soluble factors in endometriosis, i.e. IFNy, TNFα, TNFβ, IL1, IL2, IL6, IL8, IL12 and IL15, VEGF, Granzyme B, and perforin.

Through 16S sRNA gene profiling the microbiome composition of faecal samples and vaginal swabs will be determined. Vaginal and faecal samples will be stored for later microbiome analysis if the the investigators see clear differences in inflammatory profiles after the dietary intervention.

Cortisol will be extracted from hair. The researcher will carefully collect a scalp hair sample of at least 0,5 cm thickness and sent these to the laboratory to analyze. The most proximal part represents the most recently grown piece of hair. Hair samples will be cut into a segment corresponding to the 4 cm closest to the scalp, reflecting cortisol secretion over the four months prior to sample collection. Cortisol extraction from hair will be carried out using an enzyme-linked immunoassay (ELISA).

Diet quality will be assessed by the Eetscore. The Eetscore is a short (Food Frequency Questionnaire) FFQ, developed to assess the Dutch Healthy Diet 2015 (DHD2015) index. The questionnaire is composed of 40 questions assessing the frequency of consumption of food items. From the Eetscore FFQ, a DHD2015-index score can be calculated, indicating the diet quality of an individual.

Ranges from 0 (unhealthy diet) - 160 (healthy diet).

Sleep quality will be assessed by a self-rated questionnaire called (Pittsburgh sleep quality index) PSQI. This questionnaire contains 19 items, generating scores for seven different components. A general score can be obtained by adding up the scores of the seven components. Currently, PSQI is the most used tool in clinical and research practice assessing sleep quality.

Minimum score: 0. Maximum score: 21. Higher scores indicate worse sleep quality.

Physical activity level will be assessed in this study to minimise confounding. Participants will fill in the (International Physical Activity Questionnaire Shor Form) IPAQ-SF, which is one of the most widely used self-report questionnaires assessing physical activity. This questionnaire assesses physical activity of the past seven days at four levels of intensity: vigorous, moderate, walking, and sitting.

The IPAQ-SF sum score is expressed in PA Metabolic Equivalent of Task (MET)-minutes per day or week. A higher score corresponds to a physically more strenuous activity.

Perceived stress will be measured using the Perceived Stress Scale (PSS), a 10-item validated psychological instrument for measuring nonspecific perceived stress. Items are designed to score how unpredictable, uncontrollable, and overloaded respondents find their lives.

Minimum value: 10. Maximum value: 50. Higher score indicates a higher level of perceived stress.

The Pain anxiety symptom scale (PASS) measures anxiety caused by pain. Questions are asked about feelings of fear of pain, cognitive anxiety, avoidance behaviour, and physiological anxiety symptoms.

Minimum value: 0. Maximum value: 200. Higher score indicates a higher pain anxiety.

The pain catastrophizing Scale (PCS) measures the degree of pain catastrophizing of the participant by measuring elements of helplessness and pessimism in relation to the ability to cope with the pain experience.

Minimum value: 0. Maximum value: 52. Higher score indicates a higher level of catastrophizing

The checklist Individual Strength (CIS) is a 20-item questionnaire addressing fatigue, concentration, motivation and activity over the past two weeks.

The CIS is not a numerical scale.

At the end of the intervention period, participants will evaluate the anti-inflammatory diet with a rating on scale, and several general questions concerning the taste, cost, and feasibility.

Minimum value: 1 Maximum value: 10. Higher scores indicates greater satisfaction with the diet.

The global level of nucleosomes and the levels of nucleosome containing specific histone post-transcriptional modifications will be analyzed in menstrual effluent and/or K2-EDTA plasma samples from healthy patients (n=50) and from patients in the SC + DI and SC + DI + CBT group. DNA extraction from K2-EDTA plasma samples or from menstrual effluent, and DNA amount quantification and fragments length qualification Analysis of the samples will be performed using Nu.Q® immunoassays according to the instructions of the SME company Volition (Belgium), allowing for the quantification of specific nucleosome structures.

To measure metabolites, to understand the impact of both interventions on metabolic pathways

High-dimensional flow cytometry will be done to analyse immune cells such as T cells, B cells, monocytes, and macrophages. Also NK cells will be analysed. Previous studies have described a key role for NK cells in endometriosis. A decreased percentage of NK cells was observed in peritoneal fluid of endometriosis patients compared to HC (Hoogstad-vanEvert et al., 2018 ). For in depth NK cell characterisation we will include markers for CD56, CD16, KIR (killer immunoglobulin receptors) and NCR (natural cytotoxicity receptors), and activation markers such as CD69.

Through 16S sRNA gene profiling the microbiome composition of faecal samples and vaginal swabs will be determined.

Cortisol will be extracted from hair. The researcher will carefully collect a scalp hair sample of at least 0,5 cm thickness and sent these to the laboratory to analyse. The most proximal part represents the most recently grown piece of hair. Hair samples will be cut into a segment corresponding to the 4 cm closest to the scalp, reflecting cortisol secretion over the four months prior to sample collection. Cortisol extraction from hair will be carried out using an enzyme-linked immunoassay (ELISA) (DRG Instruments GmbH, Marburg, Germany). Analysis of the samples will be performed according to the instructions of the ELISA kit manual at Biopsychology - TU Dresden (Germany).