What causes fatigue in IBD?

What this research looked at

Fatigue severely impacts the quality of life and well-being of people with Inflammatory Bowel Disease. It affects up to 8 in 10 people with IBD during active disease and up to 4 in 10 people when in remission. Although very common, there has been little research into fatigue in IBD, and diagnosis and treatment options remain poor. 

Much of our knowledge of fatigue comes from studying it in other chronic conditions. From this, we know that fatigue has two main categories and drivers – central fatigue driven by the brain, and peripheral fatigue driven by the muscles. Central fatigue is thought to be the result of reduced heart and lung fitness, which leads to a decreased blood supply to the brain. Peripheral fatigue is thought to result from reduced muscle mass and function. 

This study aims to unravel the major causes of fatigue in IBD. The study involved people with Crohn’s who do not have active disease. The researchers assessed fatigue severity in these patients and a separate group of healthy volunteers to act as controls. 

The researchers assessed peripheral fatigue by measuring muscle fitness and strength during exercise, as well as the ability of the muscles to recover after exercise. They assessed central fatigue by measuring blood flow from the heart and to the brain of participants before, during and after exercise. 

What the researchers found

The study found that people with Crohn’s have reduced skeletal muscle quality, meaning that the rate that their muscles replenished energy was lower than the volunteers of the same age and BMI who did not have Crohn’s.

Physical inactivity is known to negatively impact on muscle structure and function.  Consistently, the research also showed that Crohn’s patients completed less physical activity on a daily basis compared to the control volunteers without Crohn’s. This may explain the loss of skeletal muscle quality in Crohn’s patients. These findings are consistent with other studies showing that people with Crohn’s tire more quickly during certain exercise tasks, compared to volunteers who did not have Crohn’s.

This reduction in skeletal muscle quality may be linked to people with Crohn’s having fatigue symptoms such as feeling tired and exhausted, even when their condition is under control (in remission). Further studies will be required to investigate this relationship in more detail.

In the meantime, the researchers have suggested that exercise training could be used to increase muscle quality for people with Crohn’s or Colitis. In turn, this may help to improve fatigue symptoms.

What the researchers think this could mean for people with Crohn's and Colitis

Understanding what is happening in the brain, heart, lungs and muscles of those experiencing fatigue could help to develop treatments that actually target the causes of fatigue in people with IBD. This would improve the quality of life of people with IBD, and increase the socioeconomic contribution that people with IBD provide to the UK. 

Who is leading the research: Dr Gordon Moran, Nottingham University Hospitals NHS Trust and the University of Nottingham 
Award amount: £118,379 (£37,935 Year 1 funded by the charity forCrohns)
Duration: 36 months
Official title of the application: Non-invasive approaches to identify the cause of fatigue in Inflammatory Bowel Disease patients
Tags: Fatigue, exercise