Impact of sleep dysfunction on anorectal motility in healthy humans

Sleep dysfunction is associated with altered gastrointestinal function and subsequently exacerbations of gastrointestinal problems. We aimed to investigate whether sleep dysfunction would influence anorectal motility as determined by anorectal manometry. The effect of anxiety on anorectal motility was also determined.

A total of 24 healthy volunteers underwent anorectal manometry. The anorectal parameters included resting and squeeze sphincter pressure, sensory thresholds in response to balloon distension, sphincter length, rectal compliance, and rectoanal inhibitory reflex. Sleep dysfunction was subjectively assessed by using Pittsburgh Sleep Quality Index (PSQI). Anxiety was assessed by the application of the State-Trait Anxiety Inventory questionnaire.

There were sixteen subjects without sleep dysfunction (7 women; mean age, 22 years) and eight subjects with sleep dysfunction (2 women; mean age, 22 years). There was no group difference in the volume threshold for rectoanal inhibitory reflux, rectal compliance or sphincter length (P = NS). Anal sphincter pressure did not differ between the groups (P = NS). The rectal sensitivity for different levels of stimulation did not differ between the groups (P = NS). Sleep quality as determined by PSQI correlated with rectal compliance (r = 0.66, P = 0.007). Although there was no differences in any manometric parameters between subjects with and without anxiety, the anxiety score correlated with rectal compliance (r = 0.57, P = 0.003).

Despite a positive association between rectal compliance and the level of subjective sleep or anxiety, sleep dysfunction did not apparently affect most of anorectal function in healthy subjects, nor did anxiety.