ABSTRACT
Background: Irritable bowel syndrome (IBS) is a stress-sensitive gut-brain disorder. The outbreak of Covid-19 has influenced the level of stress and anxiety at least for some people. Individuals with IBS often report poor self-rated health (SRH), which also reflects psychological and social aspects of life and an overall sense of well-being. This populationbased twin study evaluates whether the Covid pandemic has affected self-reports of abdominal symptoms of IBS and ratings of physical (p_SRH) and mental health (m_SRH) among individuals with IBS. Further, we calculate measures of twin similarity and correlations across traits to gain insights into the importance of genetic influences. Methods: In July 2021, we invited 17138 twins from the Norwegian Twin Register to complete a questionnaire asking how the pandemic affected their health and well-being, including depression, perceived stress, loneliness, anxiety, chronic somatic and pain-related diseases. Responses were received from 9032 twins, aged 19 – 86 of whom 831 reported a positive history of IBS (Table 1). Hierarchical regression models were used to estimate the impact of IBS on p_ SRH and m_SRH during the Covid pandemic, covariates in the stepwise modeling included age, sex, education, and other chronic physical and mental health conditions. Phenotypic, intraclass and cross-twin cross-trait correlations were computed for IBS and the health measures. Results: The majority of individuals with IBS reported no changes in abdominal pain or bowel disturbance during the pandemic. Nonetheless, they did report worse perceptions of health compared to those without IBS. Further findings revealed weak but significant associations between IBS and changes in perceived stress. Age was inversely related to ratings for p_SRH and m_SRH, with younger participants reporting that their mental and physical health worsened more than older participants. IBS retained significance as a predictor of worsening m_SRH after accounting for depression and perceived stress (model 5, Table 2) [OR = 1.22 (1.00;1.50), Table 2]. The intraclass correlations for worse p_SRH and m_SRH were greater among monozygotic (MZ) than dizygotic (DZ) twins, which is consistent with genetic variance explaining some of the differences in how the pandemic has affected perceptions of health. Cross-twin cross-trait correlations between IBS and worse p_SRH were 0.15 (0.11;0.18) for MZ twins and 0.08 (0.03;0.12) for DZ twins, suggesting that common genetic factors may underlie this relationship Conclusion: Abdominal symptoms of IBS did not change during the pandemic. However, IBS was predictive of worsening of mental SRH, not confounded by depression or perceived stress. These results underscore the role of psychosocial and emotional factors for mental health in IBS during the pandemic. (Table Presented) (Table Presented) (Table Presented) (Table Presented)