The association of chronotype with sleep quality and mental health in dialysis patients: A cross-sectional study

Background Patients on hemodialysis commonly experience poor sleep quality, fatigue, and depression. Chronotype may influence these outcomes, but its role in this population remains unclear. Objectives This study examined associations among chronotype, sleep quality, fatigue, and depression, and tested the mediating role of sleep quality. Methods In this cross-sectional study of 157 patients on hemodialysis (mean age, 63.99 years; 58.6% male), chronotype (Morningness–Eveningness Questionnaire), sleep quality (Pittsburgh Sleep Quality Index [PSQI]), fatigue (Fatigue Severity Scale [FSS]), and depression (Beck Depression Inventory [BDI]-II) were assessed. Correlation and mediation analyses were used to examine these relationships. Results Evening types (38.2%) had significantly poorer mean ± standard deviation PSQI scores (12.57 ± 3.37) than neither types (53.5%; 9.73 ± 4.23, p < 0.001) and morning types (8.3%; 8.23 ± 4.36, p = 0.001), particularly in terms of sleep duration, efficiency, and medication use. Fatigue (FSS score=4.63 ± 1.17) and depression (BDI-II score=9.07 ± 7.81) did not differ according to chronotype. Discussion Evening chronotype was associated with poorer sleep quality, which in turn was linked to increased fatigue and depression. Targeted sleep interventions for evening types may improve outcomes by correcting circadian misalignment and enhancing sleep efficiency. Sleep hygiene education and timed light exposure may offer clinically meaningful benefits in terms of sleep and psychological well-being.