The aim of this study was to determine if chronic stress in adulthood might influence the effect of childhood trauma on IBS in adulthood. Our study consisted of following three parts: (i) Confirming the relationship between childhood trauma as well as recent adverse life events (RALs) and development of IBS when controlling for other potential confounders using multivariate logistic regression model (ii) Determining the correlation between childhood trauma and severity of symptoms as well as quality of life in IBS patients when stratified by RALs (iii) Exploring the differences in severity of symptoms and quality of life between IBS patients who had experience of childhood trauma with or without RALs.
Data was collected from 50 healthy controls (HCs) and 56 consecutive patients who were found to have IBS in Tongji hospital and Sijing hospital in Shanghai, China from October 2017 to June 2019. This was a case-control study including basic information and medical records about childhood trauma, RALs, severity of symptoms and life quality. The diagnosis of IBS was based on Rome III. This study was approved by Ethics Committee of Tongji Hospital (2017-407) . The subjects were compensated for completion of a medical history and questionnaires.
Questionnaires
Childhood Trauma Questionnaire (CTQ) is a 28-item tool including five types of maltreatment domains (physical, emotional and sexual abuse, and physical and emotional neglect) during childhood and adolescence (before age 18). Items on the CTQ ask about experience in childhood and adolescence and the items are rated on a 5-point Likert-type scale ranging from Never True to Very Often True. The score range of 5-8, 5-7, 5-5, 5-9 and 5-7 are considered as “none or minimal” childhood trauma in the domain of emotional abuse, physical abuse, sexual abuse, emotional neglect and physical neglect respectively. In this study, IBS patients with score exceeding upper limit of “none or minimal” in any domains and overall CTQ score > 50 were regarded as patients with childhood trauma[19].
Life Event Scale (LES), which was translated for Chinese version, was used to assess the adverse life events within one year. The questionnaire consists of 48 common life events including 28 items about family and life, 13 items about work and study, and 7 items about sociality. The IBS patients recorded the events within one year and rated relevant items on a 5-point Likert-type scale ranging from 0-4 regarding the extent of influence. Meanwhile, the duration of these events was classifed into 4 groups including within 3 months, 6 months, 12 months and over 12 months and ranged from 1-4. The influence score ˣ duration score was the final score of each items. The overall score of recent adverse life events in LES was defined as summary of score on adverse items. The patients with overall score greater than 0 were regarded as recent adverse life events positive (RALs(+)).
Irritable Bowel Syndrome – Quality Of Life (IBS-QOL) was adopted and translated into Chinese version, which consisted of 34 items reflecting 8 domains. Each item was rated on a 5-point Likert-type scale ranging from Not at all to Completely. Higher values represent worse symptom and quality of life[20].
Irritable Bowel Syndrome – Severity Scoring System (IBS-SSS) was a validated scoring system using variables : current abdominal pain by visual analog scale (VAS) of 0-100 and frequency of abdominal pain; current abdominal distension by VAS of 0-100; the degree of satisfaction of evacuative behavior by VAS of 0-100; the degree of IBS interference with normal work and social activities by VAS of 0-100. Higher values represent worse symptom[21].
MOS 36-item Short-Form Health Survey (SF-36) was a validated self-reported questionnaire to measure the general health status, consisting of 36 items and 8 domains (physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role and mental health). The physical component summary (PCS) included the first four domains while the mental component summary (MCS) contained the last four domains. The higher score of each summary indicated less health-related reduction of life quality[22].
Statistical Analysis
All analyses were performed using R language ver 3.1.1 (R Foundation for Statistical Computing, Vienna, Austria). To explore the odds of IBS from chilhood trauma and RALs, the multivariate logistic regression analysis using backward stepwise selection was used to identifiy the risk of childhood trauma and RALs when adjusting for other potential confounders such as age, gender, body mass index, education background and marital status. Linear regression model and pearson’s correlation were used to evaluate the relationship between childhood trauma and severity of symptom as well as life quality. For all correlation analysis, we considered an absolute value of coefficient below 0.3 as a weak correlation, 0.3 to 0.5 as a moderate correlation and above 0.5 as a strong correlation, as recommended by Cohen. Student t-test was used to explore the difference in severity of symptoms and quality of life between IBS patients who had experience of childhood trauma with or without RALs. All reported P values were two-sided with P<0.05 defined as statistical significance.