Insomnia in maintenance haemodialysis patients

Background. Studies in the last 15 years have shown a high prevalence of sleep disorders in maintenance haemodialysis (HID) patients. Methods. To investigate whether the new technical and therapeutic advances of the last decade have had a positive impact on sleep disturbances in HID patients: 694 patients (384 males, 310 females) were surveyed using a specific questionnaire; their clinical, lifestyle and dialysis data were also recorded. Results. Forty-five per cent of patients (n=311; 156 males, 155 females) complained of insomnia, defined either by delayed sleep onset and or night-time waking. and were included in the insomnia group; the remainder were used as controls (control group). There was a significantly higher risk of insomnia in patients with >12 months on dialysis, in patients dialysed in the morning (P<0.003), and in patients with higher parathyroid hormone (PTH) levels (P<0.05). Body mass index, body weight gain and blood pressure did not differ between the groups, and neither did the dialysis parameters. Creatinine and urea plasma levels were higher in the control group vs the insomnia group (P<0.001), but there was no difference in haemoglobin concentrations or use of erythropoietin, calcitriol and antihypertensive drugs. Cigarette smoking, caffeine or alcohol intake were comparable in the two groups. The most frequently recorded sleep disorders were night-time waking (92%), trouble falling asleep (67%) and early morning waking (62%). Restless leg symptoms were described in 52% of patients with insomnia. Conclusions. The prevalence of insomnia in HD patients is still very high; elderly patients, and those with longer time on dialysis and high levels of PTH are at major risk of insomnia, whereas type of dialysis, haemoglobin levels and behavioural factors do not seem to play a critical role in determining this sleep disorder.