Sleep disruption in patients with sleep apnea and end-stage renal disease

Abstract

Objectives: Sleep apnea (SA) is common in patients with end-stage renal disease (ESRD) and such patients are likely to suffer additional sleep disruption associated with restless legs syndrome (RLS) and periodic leg movements (PLM). Our objective was to evaluate sleep quality in ESRD patients who are newly diagnosed with SA and determine the additional contribution of PLM to sleep disruption. Methods: Two groups of patients with SA (apnea-hypopnea index (AHI) > 15) were compared, one with ESRD (n = 12) and the other with normal renal function (n = 18), using a sleep history questionnaire, sleep diary, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, polysomnography (1 night) and actigraphy (6 nights). Results: The prevalence of RLS was higher in ESRD patients (60% vs 6%, p < 0.001). ESRD patients had shorter total sleep time (TST) (264 ± 78 vs 330 ± 46 min, p = 0.01), lower sleep efficiency (68 ± 20% vs 81 ± 11%, p = 0.03), and more stage 1 NREM sleep (23 ± 18 vs 8 ± 5 % TST, p = 0.002). ESRD patients had a higher frequency of PLM (31 ± 37 hr-1 vs 8.0 ± 16 hr-1, p = 0.02) and PLM-related arousals (15 ± 18 hr-1 vs 1 ± 2 hr-1, p = 0.003). Actigraphy demonstrated a higher movement and fragmentation index in ESRD patients (23 ± 10% sleep time vs 17 ± 6% sleep time, p = 0.04). Conclusions: The co-existence of PLM is an additional source of sleep disruption in patients with ESRD and SA. Treatment of PLM, in addition to treatment of sleep apnea, may be required to improve sleep quality in this patient population.