Physical activity, disease activity, quality of life, and social support among Japanese people with inflammatory bowel disease: a cross-sectional study

Introduction: Physical activity levels are often lower in people with inflammatory bowel disease (IBD) than in healthy individuals. However, no studies have examined physical activity levels and associated factors among Japanese people with IBD. This study aimed to examine physical activity levels and their associations with other factors, including disease activity and quality of life (QOL). Methods: A nationwide online survey was conducted through an online community for people with IBD. Physical activity was assessed using the short version of the International Physical Activity Questionnaire and classified into low and moderate-to-vigorous intensity groups based on World Health Organization guidelines. Disease activity was evaluated using the Simple Clinical Colitis Activity Index (SCCAI) for ulcerative colitis and the Harvey-Bradshaw Index (HBI) for Crohn’s disease. QOL was measured using the Inflammatory Bowel Disease Questionnaire-32 (IBDQ-32). Binary logistic regression was used to identify factors associated with physical activity level, and simple linear regression to evaluate associations between physical activity and both disease activity and QOL. Results: Overall, 232 participants (mean age 39.9 years, 62.1% women) completed the survey, with 45.3% in the low intensity group and 54.7% in the moderate-to-vigorous intensity group. Most participants were in remission or had mild disease activity (mean SCCAI score 2.85; mean HBI score 4.40). The median weekday sitting time was 420 minutes/day. None of the demographic, physical, or social support variables were significantly associated with physical activity level. Physical activity level was not significantly associated with disease activity in either ulcerative colitis (p = 0.24) or Crohn’s disease (p = 0.50) but had a significant positive association with IBDQ-32 total score (p = 0.03) and the emotional function (p = 0.03) and social function (p = 0.04) subscales. Conclusion: Physical activity levels among Japanese people with IBD were similar to those in other countries, but sitting time was longer. In our study population, who mostly had no more than mild disease, physical activity was not adversely associated with disease activity and had positive associations with emotional and social QOL. We suggest that physical activity can therefore be safely recommended to this population, with implications for nursing practice.