— Upping routine activity may be an effective therapy for irritable bowel syndrome
by Diana Swift, Contributing Writer June 3, 2020
A higher number of daily steps was associated with reduced severity of irritable bowel syndrome (IBS) symptoms in young people, Japanese researchers found.
Toyohiro Hamaguchi, PhD, of the School of Health Sciences at Saitama Prefectural University, and colleagues analyzed the impact of physical activity levels on gastrointestinal (GI) symptoms in 101 “mildly affected” university students and found that the amount of locomotor activity could distinguish between minor and moderately severe discomfort.
As the team reported in PLoS One, the probability that locomotor activity level could discriminate between 5 versus 4 points on the Gastrointestinal Symptom Rating Scale (GSRS) — with 5 being the threshold for severe symptoms — fell in accordance with increases in steps taken each day. For example, at 4,000 steps, the probability was 78%; at 6,000, it was 70%; at 8,000, it was 59%; and at 10,000, it was 48%.
“This study demonstrated that the severity of GSRS is associated with the amount of walking in younger people with IBS,” the investigators wrote. “Based on our findings, increasing the daily step count to 9,500 steps from 4,000 steps will result in 50% reduction in the severity of symptoms.”
They said the results provide clinicians with information on how many steps to add to an IBS patient’s current physical activity level to reduce GSRS by 1 point. The researchers cautioned, however, that the effect of exercise on symptom improvement in patients with mild-to-moderate discomfort is small and was significant only in the female IBS patients, and that future studies are needed to determine the amount of activity required to reduce GSRS scores.
Previous research has shown long-term improvement in IBS symptoms in physically active patients compared with physically inactive patients.
“As could be expected based on previous studies demonstrating improvement in IBS symptoms with exercise, these investigators observed an inverse correlation with daily steps and gastrointestinal symptom severity in the IBS population, especially women,” commented Brooks Cash, MD, of the University of Texas Health Science Center at Houston, who was not involved with the new study.
“They suggest there may be diagnostic value in measuring physical activity parameters such as step counts to estimate IBS symptom severity as well as to determine targets for physical activity to reduce symptom severity,” he told MedPage Today.
Cash urged interpretive caution, however, given the study’s predominantly young population, the absence of IBS-specific metrics, and the absence of patient blinding to trial objectives. “This last issue, coupled with the lack of compliance verification inherent in the methods of physical activity estimation with pedometers and the well-recognized high placebo response inherent to IBS studies, significantly limit the conclusions that can be drawn from this study,” he said.
“However, the findings are thought-provoking and hypothesis-generating and lend support for future rigorous, blinded, randomized controlled trials of physical activity as a first-line therapy for IBS,” he added.
Study Details
For the study, the researchers recruited 78 female and 23 male students with a mean age of 20 who were diagnosed with mild IBS and recruited from 2015 to 2018. Across subtypes, 42 of the participants had IBS-constipation, 29 had IBS-mixed, and 25 had IBS-diarrhea. Mean body mass index was 23 for females and 21 for males.
All were assessed at baseline with the GSRS, which measures 15 items across five GI symptom clusters including reflux, abdominal pain, indigestion, diarrhea, and constipation. On the GSRS 7-point Likert-type scale, a score of 1 indicates the absence of troublesome symptoms, while 7 indicates very troublesome symptoms. Baseline GSRS scores were similar in both sexes.
Walking patterns were then tracked for 1 week with participants using a commercial pedometer, and no significant intersex differences in step-counts emerged, the researchers noted. The association between the GSRS score and pedometer counts was determined by ordinal logistic modeling analysis.
Hamaguchi and co-authors explained that mild physical activity helps clear intestinal gas and reduces bloating, and that 30 minutes of daily walking is recommended for increasing colon transit time in adults with chronic constipation. In addition, recent research has demonstrated that inflammatory biomarkers such as interleukin-6 and tumor necrosis factor-alpha were attenuated after 24 weeks of moderate-intensity aerobic exercise.
Study limitations, the researchers noted, included that it did not address the impact of participants’ concomitant medications or eating patterns in the context of activity levels, and that participants included only young people, whose exercise targets differ from those of elderly patients. In addition, since symptoms vary with age, studies in larger cohorts should stratify by age and IBS subtype to further investigate the relationship between physical activity and digestive symptoms, the team said. There may also have been information bias — participants were told at the time of consent that IBS symptoms respond to physical activity and so some may have deliberately increased their daily step count. Finally, IBS diagnosis was based on the Rome III criteria, as the study was designed in 2015, and these have since been replaced by the Rome IV version.
The research was funded by the Japan Society for the Promotion of Science and supported by staff at Saitama Prefectural University.
Hamaguchi and co-authors reported having no conflicts of interest.
Cash disclosed no competing interests in relation to his comments.