Revista de nefrología y terapéutica

Sleep Disorders in Hemodialysis Patients: Does RKF Matter?

Abstract

Haitham Ezzat *,Osama Mahmoud ,Amr Mohab ,Huseen Sayed

Background: Sleep disorders are common in ESRD. Residual kidney function contributes significantly to the overall health and well-being of dialysis patients. The importance of RKF in patients on peritoneal dialysis is widely known, but only a few studies have examined RKF in patients on hemodialysis. Methods: Our study aimed to evaluate sleep disorders in hemodialysis patients and the effect of residual renal function on them. A cross sectional study was conducted on 80 HD patients who were divided into 2 groups. Group I included 30 HD patients with RKF and group II included 50 HD patients without RKF. RKF (Kru) was calculated using the equation: Interdialytic urine volume x Urine urea concentration/Interdialytic period/Mean BUN. Where Mean BUN= (BUN 1 + BUN 2)/2. BUN 1 was measured after first dialysis of week and BUN 2 was measured prior to second dialysis of week. Routine laboratory investigations were done to all patients. We assessed the following sleep disorders in both group: insomnia through insomnia severity index, the restless leg syndrome through international restless leg syndrome study group (IRLSSG) and the excessive Daytime sleepiness through the Italian version of Epworth sleepiness scale. Results: In group I, 43.3% were female and 56.7% were male with mean age 40.47 ± 13.96 years and mean dialysis duration 4.38 ± 2.86 years. In group II, 38% were female and 62% were male with mean age 54.68 ± 9.36 years and mean dialysis duration 6.90 ± 3.82 years. There was highly significant difference between both groups regarding age and dialysis duration (p=0.000, 0.002 respectively). There was highly significant difference between the two groups regarding iPTH (106.71 ± 57.34 pg/ml, 175.36 ± 15.71 pg/ml, p=0.000). The prevalence of insomnia was 62% followed by IRLS 18.7% and EDS 12.5%. There was no statistically significant difference between group I and group II regarding insomnia severity index, while there was statistically significant difference between them regarding international restless limb syndrome and epworth sleepiness (p=0.040, 0.004 respectively). There was no significant correlation between Kru and total score of insomnia severity index, total score of limb syndrome and total score of epworth sleepiness scale. In our study there was positive correlation between Phosph and total score of limb syndrome (p=0.010). Also the level of iPHT was correlated with the total score of limbs syndrome and total score of Epworth sleepiness scale (p=0.027, 0.038 respectively). Conclusion: Sleep disorders are quite common in the HD patients. Patients with high level of iPTH and phosphorus are at major risk of sleep disorders. Residual kidney function is very important to control Ca, phosphorus and iPTH level but its effect on the sleep disorders is not obvious in our study.