The Links Between Sleep and Gastrointestinal Health
Sleep disturbances are common in those with gastrointestinal disease but we still don’t know whether these diseases are caused by sleep problems or if sleep problems have a negative effect on gastrointestinal health. This relationship led researchers to publish an article in the journal Gastroenterology & Hepatology that examined the link between sleep and various gastrointestinal illnesses.
Gastroesophageal reflux disease (GERD) and sleep
Researchers found that two out of every three individuals who experienced weekly heartburn reported that their symptoms affected their ability to sleep. In addition, the risk of GERD symptoms in those with insomnia was three times greater compared to those without sleep complaints. GERD has also been found to affect between 58 percent and 62 percent of patients with obstructive sleep apnea (OSA).
The link between GERD and sleep
The decrease in swallowing and saliva production during the night can increase gastric reflux — and this may be to blame for disturbed sleep. With that being said, the review in Gastroenterology & Hepatology pointed to a study that found the severity of erosive esophagitis increased as sleep quality declined. Obesity has also been linked to an increase in GERD episodes and obesity is a known risk factor for OSA.
Irritable bowel syndrome (IBS) and sleep
The article reported that functional dyspepsia (discomfort in the upper abdomen) and IBS was a statistically significant risk factor for poor sleep and that 57 percent of those with IBS and/or functional dyspepsia reported that abdominal pain or discomfort disrupted their sleep.
Explaining the link between IBS and sleep
IBS and abdominal discomfort is associated with higher levels of arousal and this can lead to poor sleep. Those with IBS have also been found to spend more time in REM sleep — the period when the brain is most active and sleep is more likely to be disturbed. One study found that women with IBS had lower nighttime levels of melatonin and tryptophan (important sleep regulators) while another found that restless legs syndrome was more common in those with IBS compared to the general population.
Inflammatory bowel disease (IBD) and sleep
The authors of the review pointed out that sleep disturbances in IBD have been a major area of scientific focus over the past several years and that 77 percent of those with active IBD experience worse sleep compared to those with inactive IBD. A separate study found that poor sleep quality was a strong predictor for clinically active IBD.
Explaining the link between IBD and sleep
The medications used to manage IBD (such as corticosteroids) can disrupt sleep. Disturbed sleep can also trigger the body’s immune system and lead to inflammation which can exacerbate colitis and have a negative effect on sleep. The authors of the review reported that sleep quality may be a modifiable risk factor that can prevent IBD flares and melatonin may improve sleep by reducing inflammation.
Colorectal cancer and sleep
The article highlighted research that found those who got fewer than six hours of sleep per night had an almost 50 percent increased risk of benign colorectal tumors compared to those who got at least seven hours of sleep. Another study found that those who worked rotating night shifts at least three nights per month for at least 15 years were at an increased risk for colorectal cancer.
The link between colorectal cancer and sleep
Insufficient sleep (typically fewer than six hours) and excessive sleep (typically more than nine hours) have both been linked to an increased risk of colon cancer and this is thought to be linked — again — to the influence of inflammatory cytokines. Short and long sleep durations are also associated with obesity which is a known risk factor for colorectal cancer.
Liver disease and sleep
Researchers pointed to studies that found one-third of nonalcoholic individuals with liver disease reported sleep difficulties and that 63 percent of those with chronic hepatitis C infection had sleep disturbances. The authors also pointed out that OSA may lead to an increase in fat accumulation in the liver, leading to nonalcoholic fatty liver disease.
The link between liver disease and sleep
Studies have found sleep is affected by chronic liver disease complicated by hepatic encephalopathy (the altered state of mind caused by liver failure) and liver disease without the presence of hepatic encephalopathy. The authors of the review suggested that cirrhosis can affect function in the area of the brain that regulates our circadian rhythm and this explains the sleep disruption associated with liver disease.
Addressing the issue of sleep and gastrointestinal health
The authors concluded their review by suggesting that since obesity plays a significant role in many gastrointestinal diseases and is also linked to sleep issues such as sleep apnea, focusing on weight reduction may improve gastrointestinal symptoms and sleep quality. They also stated that since control of gastrointestinal issues can improve sleep, it is important for gastroenterologists to investigate a patient’s sleep history to ensure better patient care.