The effects of poor sleep quality on cognitive function of patients with cirrhosis

Objectives: This study was conducted to assess the ill-defined relationship between sleep quality and multiple, specific domains of cognitive function in patients with cirrhosis. Methods: A comprehensive battery of neuropsychological tests (divided into six neurocognitive domains) and a standardized, validated measure of sleep quality (Pittsburgh Sleep Quality Index [PSQI]) were administered to patients with cirrhosis and without evidence of overt hepatic encephalopathy, recruited from liver transplant and advanced liver disease clinics (n = 34). An inflammatory bowel disease (IBD) control group (n = 23) was similarly recruited and evaluated to control for the secondary effect of a chronic illness on cognition. PSQI global and component scores were used to predict cognitive function in each neurocognitive domain, using linear regression Results: Global PSQI scores were significantly higher (indicating poorer sleep quality) in the cirrhosis group (median [range] = 10 [1-19]) than in IBD controls = 5 (1-14); p = 0.002). After controlling for age and education, short duration of sleep was associated with impaired memory for patients with cirrhosis; the use of soporific agents was associated with poor visual-perceptual function in patients with IBD. Conclusions: Poor sleep was associated with worsening of the already impaired cognitive function of patients with cirrhosis.