#258 To sleep or not to sleep: that is the (renal) question

Abstract Background and Aims Sleep disturbances are common in patients with chronic kidney disease (CKD), with a prevalence around 45%–80%. Poor sleep quality is related to the onset or progression of cognitive and mood disorders, cardiovascular and respiratory diseases and a worsening of the quality of life. The reason for the closed link between these seemingly distant pathologies finds its origins in the pathophysiology of CKD and its complications. Our aim is to analyze the quality of sleep in patients with CKD, observing whether there are differences between patients in end-stage renal disease (ESRD) in conservative therapy and patients on replacement therapy (RT): hemodialysis (HD), peritoneal dialysis (PD), kidney transplantation (TPX). Method We conducted a retrospective cohort study on 155 nephropathic patients undergoing conservative therapy or RT (HD/DP/TPX) for at least 2 months belonging to the “Sant’ Andrea” University Hospital and the Local Health Unit “ASL Roma 4.” The outcome variable analyzed was sleep quality, measured by administering the Pittsburgh Sleep Quality index (PSQI), whose overall score was dichotomized into good (≤5) and poor (>5) quality. A multivariate logistic regression model was applied, corrected for age, comorbidities (cardiovascular disease, diabetes, obesity, hypertension, respiratory disease) and blood nitrogen, sodium, potassium, calcium, phosphorus, parathormone, hemoglobin. Results The mean (SD) age of patients was 63.7 (14.6) years. The females were 31.8%. The 60.5% of patients obtained a global score greater than 5. We didn't observe significant differences in the items and in the global score between the various modalities. The lowest median global score, so the best one, was found in ESRD patients (Fig. 1). HD patients were found to have shorter sleep duration, longer sleep onset latency and a higher percentage of PSQI >5. PD patients had a higher subjective sleep quality, lower prevalence of sleep disturbances and a better PSQI compared to hemodialysis (Fig. 2). Sleep disturbances were found to be more frequent in females (68% vs 57%), with a worse daytime fitness state (P = 0.004). Lower hemoglobin values, especially if associated with comorbidities such as respiratory system diseases, can compromise not only the daytime fitness state reported by the patient (P = 0.0176), but also the global quality of sleep (P = 0.064). All patients tested was positives for sleep disorders, but only 20 (12.9%) of them were taking sleep-inducing drugs. Conclusion The results of the study show that although ESRD patients often have many symptoms related to pre-dialysis uremia, they still have a better quality of sleep than patients on RT. Therefore RT have an impact on sleep quality that should not be underestimated. Contrary to what one might think, PD does not have a worse impact on sleep than HD, even though it is a modality that is often performed at night. It will be interesting to expand the study by correlating these data with the execution of polysomnography to describe the sleep disorders detected both from a qualitative and quantitative point of view. For a first screening we could also benefit from the use of smart devices (smart watches or rings). Furthermore the extremely limited use of sleep-inducing drugs, even in presence of very poor sleep quality, may suggests that nephrologists have not yet developed care to the issue. Higher attention to this aspect can improve patient's quality of life and reduce the risks associated with sleep disorders.