Background: Sleep complaints are common in haemodialysis patients. In the general population, insomnia impacts negatively on health-related quality of life (HRQoL). The objective of this study was to examine the association between quality of sleep and HRQoL in haemodialysis patients independent of known predictors of HRQoL.
Methods: Quality of sleep was measured using the Pittsburgh Sleep Quality Index (PSQI) and HRQoL was measured using the Medical Outcomes Study 36-item Short Form (SF-36) in 89 haemodialysis patients.
Results: Sixty-three (71%) subjects were 'poor sleepers' (global PSQI >5). The SF-36 mental component summary (MCS) and physical component summary (PCS) correlated inversely with the global PSQI score (MCS, r = -0.28, P < 0.01; PCS, r = -0.45, P < 0.01). The PCS score also correlated with age (r = -0.24, P = 0.02), haemoglobin (r = 0.21, P = 0.048) and comorbidity (r = -0.40, P < 0.01), and mean PCS was lower in depressed subjects (26.2 vs 35.9, P = 0.02). Subjects with global PSQI >5 had a higher prevalence of depression, lower haemoglobin and lower HRQoL in all SF-36 domains. The global PSQI score was a significant independent predictor of the MCS and PCS after controlling for age, sex, haemoglobin, serum albumin, comorbidity and depression in multivariate analysis.
Conclusions: Poor sleep is common in dialysis patients and is associated with lower HRQoL. We hypothesize that end-stage renal disease directly influences quality of sleep, which in turn impacts on HRQoL.