Individuals who sleep more or less than average report significantly more constipation, compared with normal sleepers, based on data from 14,590 adults.
“Normal sleep duration is thought to be essential for healthy bowel function; however, the effect of either limited or excessive sleep duration on bowel patterns is poorly understood,” Adeyinka Adejumo, MD, of North Shore Medical Center, Salem, Mass., and colleagues wrote in an abstract released as part of the annual Digestive Disease Week®, which was canceled because of COVID-19.
To examine the association between sleep duration and bowel function, the researchers identified 14,590 adults aged 20 years and older who completed questionnaires on sleep and bowel health as part of the National Health and Nutrition Examination Survey (NHANES) during 2005-2010.
Sleep was divided into three categories based on standards from the National Sleep Foundation: short (less than 7 hours), normal (7-8 hours) and long (more than 8 hours).
Overall, constipation rates were significantly lower among normal sleepers (8.3%) compared with both short and long sleepers (11.0% and 12.5%, respectively; P < .0001 for both).
Bowel function was defined as normal, constipation, or diarrhea based on stool form and bowel movements per week. After controlling for demographic, lifestyle, and dietary factors, long sleepers and short sleepers were 61% and 38% more likely, respectively, to report constipation, compared with normal sleepers.
However, sleep duration was not related to diarrhea, the researchers noted. In addition, “A sensitivity analysis revealed that sleep duration did not mediate the relationship between comorbid factors (such as overall health, poverty index, obesity, and body mass index) and constipation,” they wrote.
The results suggest that decreased sleep is associated with constipation among adults in the United States, the researchers said. However, “further studies are needed to evaluate the physiologic mechanisms driving the impact of sleep duration on bowel function to determine whether sleep disorders or their underlying causes affect constipation,” they concluded.
“This study was necessary because up to 50% of Americans suffer from sleep disorders, out of which abnormal sleep duration is one of the most common and underdiagnosed, and associated with other diseases such as hypertension and diabetes,” Dr. Adejumo said in an interview. “However, disorders of bowel function (constipation and diarrhea), which affect almost 10%-15% of the population and result in significant health care burden, such as higher cost, hospital visits, abdominal discomfort, have not been studied among individuals with suboptimal sleep duration.”
Dr. Adejumo said he and his colleagues were surprised by their findings. “Although, based on our hypothesis, we thought that sleeping too long may be associated with constipation, we were shocked to note similar results among people who also sleep for short durations,” he noted.
“Previous studies had suggested that bowel contraction slows down considerably during sleep. It, therefore, will make sense that sleeping for too long may result in suppressed bowel motility and decreased bowel movement,” he said. “However, our results showed similar findings among short sleepers. We do not know the exact mechanism of these results. It may be that short sleep resulted in inadequate bowel rest, bowel muscle fatigue, and, subsequently, decreased bowel movement,” said Dr. Adejumo. “Or it may also be that brain-gut signaling pathways are disrupted among short sleepers, as is seen among IBS patients after a poor night sleep, resulting in higher constipation,” he added.
Clinicians should be aware of the impact of both short and long sleep on constipation, said Dr. Adejumo. “Individuals who are unable to have adequate periods of sleep due to other diseases, including insomnia, disrupted job schedules, or conditions with too long sleep, such as narcolepsy, may all additionally suffer from constipation. Such patients may need regular evaluation and treatment for constipation to improve their discomfort,” he said.
“To confirm our findings, other clinical studies with more granular data on sleep and constipation, are needed, as well as translational research to uncover the potential mechanisms of these findings,” he emphasized.
The researchers had no financial conflicts to disclose.
SOURCE: Adejumo A et al. DDW 2020. Abstract Sa1711.