Abstract
Background and Aims
Sleep quality is an important and determining factor in the quality of life (QoL) during dialysis. The prevalence of sleep disorders in the general population varies between 10 and 40%; this figure increases to 50% in dialysis patients.
This study was conducted to determine which factors influence sleep quality in end stage renal disease patients on automated (APD) and continuous (CAPD) ambulatory peritoneal dialysis.
Methods
This was a cross-sectional study which included stable patients from two Peritoneal Dialysis Units. We excluded patients who weren’t able to understand the questionnaires, the language and the ones who had hospitalar admissions in the previous 3 months. Pittsburg Sleep Quality Index (PSQI) was used for assessing sleep quality (the higher the score, the lower the sleep quality), while quality of life parameters were assessed by self-administered EuroQol questionnaire (EQ-5D-5L). The presence of depressive symptoms was made with Patient Health Questionnaire (PHQ-9). In all patients, demographic variables, Charlson Comorbidity Index (CCI), clinical and laboratory parameters were recorded and analyzed. Descriptive statistics was performed. Two groups were created according to Pittsburg Sleep Quality score: G1 (n=42) - “poor” sleep quality and G2 (n=28) - “good” sleep quality. Groups were compared using independent t-test for comparison of continuous variables and Chi square test for categorical variables. In order to evaluate relationship between sleep quality and the other variables multivariate logistic regression and Pearson bivariate analysis were used.
Results
The study enrolled 70 patients (male/female 44/26; mean age 55.3±14.6 years; APD/CAPD 25/45; PD duration 28±24.2months). One third (31.4%) of the patients was diabetic, 12.9% presented cardiac insufficiency and 20% had cardiovascular disease. 50% of our population had a sleep disorder, although the majority of the problems were slight to moderate.
We found that PD patients who sleep better (G2) had significant better life quality (p<0.001), lower CCI (p<0.001) and were less depressed (p<0.001). 77.3% of the patients with worst sleep quality (G1) were diabetic (p=0.04), regardless glycemic control and hemoglobin A1c.
There were no significant differences between the two modalities of peritoneal dialysis (APD and CAPD patients), between genders or in patients who were PD first. We found no significant association between sleep quality and dialysis efficacy (weekly kt/v).
Multivariate analysis (linear regression) showed a significant association between sleep quality and EuroQol (ExpB=0.000; IC 95% 0.000 to 0.054; p=0.002) and, depression (ExpB=1.274; IC 95% 1.045 to 1.552; p=0.017) in a model adjusted to age, PD duration and diabetes.
Conclusion
Our results show that poor sleep quality seems to be linked to life quality, comorbidity burden and depression. A better understanding of risk factors associated with poor sleep quality may help to signalize the patients who may benefit of specific treatment. The PSQI survey is a simple tool offering very complete information on sleep quality. The implementation of actions aimed at improving the hygiene of sleep may be an excellent way to improve the patients’ quality of life in an efficient and effective manner.