IBS and sleep

SLEEP IMPAIRMENT IN FEMALE PATIENTS WITH IRRITABLE BOWEL SYNDROME (IBS) AND ITS ASSOCIATION WITH SYMPTOM SEVERITY AND HEALTH-RELATED QUALITY OF LIFEExecutive summary Irritable bowel syndrome (IBS), which affects 10-20% of adults, leads to severely impaired health-related quality of life (HRQOL). In a preliminary report, we showed that IBS patients suffer from fragmented sleep associated with excessive daytime sleepiness and impaired HRQOL. However data on sleep in IBS are scant and associations between IBS and sleep quality have not been sufficiently elucidated. We hypothesized that sleep impairment leads to increased GI symptoms and reduced HRQOL. The study aims were to: 1) characterize sleep impairment in IBS in terms of subjective reporting, objective ambulatory sleep studies, and alterations in nocturnal melatonin levels; 2) assess the effect of sleep impairment on IBS symptoms and HRQOL; and 3) determine associations between sleep impairment and nocturnal melatonin levels with IBS symptoms and psychosocial variables.

We conducted a prospective controlled study of sleep architecture and efficiency in women with IBS compared to matched, healthy controls, and the effects of impaired sleep on GI symptoms and HRQOL. Socio-demographic variables and psychosocial variables were measured by baseline questionnaires and self-reported sleep quality was measured by validated sleep questionnaires at baseline. Sleep diaries were completed by all subjects during the course of the actigraph and peripheral arterial tone (PAT) measurements and for 10 additional days. Objective sleep quality was measured by actigraphy and PAT. Urinary nocturnal levels were measured by ELISA.

Twenty-six IBS patients and 21 HC completed the ambulatory sleep study (actigraphy and PAT) and the nocturnal urinary melatonin collection. There were no statistically significant differences between the two groups in socio-demographic characteristics. The IBS group had significantly lower scores than the HC on the SOC questionnaire (greater impairment in sense of coherence) and significantly higher scores than HC on the General Severity Index (GSI) of the SCL-90R questionnaire (greater psychological distress). The IBS group also had significantly higher scores on the anxiety sub-scale of the SCL-90R. IBS patients had significantly higher scores on the Pittsburgh and MSQ questionnaires, indicating lower subjective sleep quality in the IBS group. In the 5-night actigraphy study the IBS group had significantly worse scores on two sleep measures: mean latency to sleep in minutes (P=0.03) and mean arm acceleration in milli-g (P=0.04). These two variables were correlated with each other as well as with psychosocial variables and subjective reporting of sleep quality.

There was great night-to-night variability in arm-acceleration. There were no differences between the groups in nocturnal melatonin levels.

The results of this study provide strong supporting evidence that IBS patients perceive their sleep as impaired and not refreshing. This perception is related to psychosocial variables including anxiety, general psychological distress, and poor coping skills. There is also objective evidence of sleep impairment in IBS, but this evidence is less compelling than the results of our previous study.

The finding of significantly increased arm acceleration in IBS patients, which is related to longer latency to sleep and less refreshing sleep (sleep diaries), reports of lower sleep quality (MSQ) and poorer coping skills (SOC) is novel and of potential clinical and research interest. It could reflect a corollary to excessive periodic leg movements in the upper limbs, a known polysomnographic finding in individuals who suffer from restless limb syndrome.

Further research is warranted into this finding and the relationship between psychosocial variables, perceived sleep quality, and arm acceleration in IBS patients.