The Subjective Sleep Quality and Heart Rate Variability in Hemodialysis Patients

Abstract

Introduction: Sleep disturbances and cardiovascular autonomic dysfunction are major complications of hemodialysis (HD). The goal of this study is to identify clinical, heart rate variability (HRV) or laboratory parameters that are independently associated with subjective sleep quality. Patient and methods: Forty-six stable HD patients filled out sleep questionnaires – Pittsburgh sleep quality index (PSQI), Athens insomnia scale (AIS), and Epworth sleepiness scale (ESS). In addition, they received analyses of 5-minute HRV twice, in lying posture before and after HD. We also recruited 50 healthy subjects who received 5-min HRV. Results: The patients with end-stage renal disease have a high rate of poor sleep quality according to PSQI, AIS, and ESS. The activities of total power (0–0.5 Hz), high-frequency power (HF, 0.15–0.40 Hz), low-frequency power (0.04–0.15 Hz), and very-low-frequency power (0.003–0.04 Hz) in HD patients are obviously lower than that in the healthy people. The poor sleepers (PSQI > 5) show lower heart rate, higher HF and variance before HD, but did not show a significant difference after HD. There is no significant difference between HRV and global score of AIS, but the insomnia group (AIS > 5) has higher BMI. These patients with sleepiness (ESS > 9) only reveal lower hemoglobin, although the global score of ESS reveals no significant relationship with HRV. Conclusion: HD patients have a high rate of poor sleep quality and autonomic dysfunction. Greater attention for the evaluation of sleep quality is needed for the better care of HD patients.