The relationshipof the quality of sleep in patients with stage 5 chronickidney disease, treated with hemodialysis, with melatonin-producing function

Abstract

The researcheddemonstrated the relationship between functional state of the pineal gland and sleepdeterioration. However, impaired melatonin-producing function of the pineal gland (MFE) in patients with chronic kidney disease (CKD), treated with hemodialysis (HD), and its association with sleep disturbance in this cohort of patients required further investigations.Aim — to assess the quality of sleepin patients with stage 5 CKD treated with HD and investigate itsrelationship with the pineal dysfunction.Materials and methods. Examinations involved 130 patients (50 % of men) with stage 5 CKD, treated with hemodialysis, with the mean age 58.5 [43; 66]. The day and night melatoninlevels (MT) in saliva were determined and based on the results the patients were divided into two groups: group I — 110 patients with impaired MFE, group II — 20 patients with normal MFE. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. All patients underwent clinical and laboratory tests: general and biochemical blood tests, office blood pressure (BP) measurements, Holter blood pressure monitoring.Results. Analysis of the insomniastructure in patients with stage 5 CKD, treated with HD, according to the PSQI questionnaire, demonstrated the problems with falling asleep in 96.2 % of patients, feeling of heat in 56.8 %, frequent awakenings in 52.9 %, daytime dysfunction in 40.8 %, breathing problems in 40.5 %, sleep problems due to coughing or snoring in 37.8 %, having bad dreams in 18.9 %, the use of sleeping meds in 8 % of patients. The total PSQI score in patients with impaired MFE was higher by 71.4 % (p < 0.001) compared to the value obtained in the group with preserved pineal gland function, demonstrating the effects of MFE on sleep quality.The component of «sleep delay» and «sleep duration» in patients with pineal gland dysfunction was 66.7 % higher than in the group with preserved MFE (p < 0.001). Comparative analysis of the number of minutes required for patients to fall asleep in the study groups demonstrateda greater sleep delay in HD-treated patients with impaired MFE. From them, the majority of subjects (71.8 %) needed more than 60 minutes to fall asleep, while in the group with preserved MFE such patients were not identified (p < 0.05). The number of patients with the period of falling asleep of 31 to 60 minutes in the group with pineal gland dysfunction was 30 % less than in patients with preserved MFE (p < 0.05). The number of patients in whom it took 16—30 minutes to fall asleep in the group with preserved MFE was 92.5 % (p < 0.05) more than in patients with pineal gland dysfunction, and patientswith the period of falling asleep of less than 15 minutes was by 62 % higher than patients with impaired MFE (p < 0.05). The decreased sleep duration was established in all patients treated with HD, however the most worsening of the sleep quality was revealed in the groupof MFE disorders. Thus, thenumber of patients with sleep duration < 5 hourswas by 90.8 % (р < 0.05) higher in the groupof impairedMFEvs group with the preserved MFE, with sleep duration of 5—6 hours by 81.7 % (р < 0.05), the number of subjects with duration of 6—7 hours by 76.4 % lower (р < 0.05), and those who slept > 7 hours by 84.0 % (р < 0.05).Conclusions. Patients with stage 5 CKD, treated with HD, were characterized with combination of MFE impairment (84.6 %) with poor sleep quality (86.2 %), including problems withfalling asleep, felling hot, frequent waking up, and daytime dysfunction. The low quality of sleep was determined bylow melatonin levels in saliva, the presence of hypoalbuminemia and arterial hypertension, hypertension duration and HDtreatment