Higher systemic inflammation is associated with poorer sleep quality in stable haemodialysis patients

Background. Increased inflammation has been noted in sleep disorder patients with normal renal function. However, the relationship between sleep quality and circulating inflammatory markers has not been previously studied in haemodialysis (HD) patients. Methods. A total of 114 HD end-stage renal disease patients receiving maintenance HD for > 3 months were included in this study. Pittsburgh Sleep Quality Index (PSQI) was used to measure individual's sleep quality. Based on the global PSQI score, patients were divided into groups of good sleepers (PSQI < 5) and bad sleepers (PSQI >= 5). Results. Twenty-three patients (20.2%) were classified as good sleepers and 91 patients (79.8%) were bad sleepers. Bad sleepers have significantly higher serum hsCRP level and lower serum phosphate level (all P < 0.05). The global PSQI score, or worse sleep quality are positively correlated with serum triglyceride level, high-sensitivity C-reactive protein (hsCRP) level, IL-1 beta level and negatively correlated with the haemoglobin and phosphate level. In the multi-variable linear regression model, levels of hsCRP (beta = 0.209, P = 0.029) and triglyceride (beta = 0.212, P = 0.025) were both significant independent predictors for the global PSQI score. Conclusion. Our study demonstrated severe impairment of sleep quality in HD patients and corroborated the role of inflammation in the pathogenesis of sleep disturbance.