Sleep disorders in hemodialyzed patients--the role of comorbidities

Sleep disorders are very frequent in hemodialyzed patients, but the relationship between these disorders and water withdrawal, urea removal and comorbidities has not been sufficiently clarified.

The study comprised a group of 88 patients in good nutritional condition, with target hemoglobin concentration, good control of blood pressure and optimal dry weight. After answering a questionnaire (SDQ) based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) patients were assigned to one of 3 groups: those with no disturbances (no.20), those with subclinical disorders (n.35) and insomniacs (n.33). Yearly fluid and urea withdrawal by dialysis and the Charlson Comorbity Index were measured.

Sleep disorders were observed in 77.27% of the patients. There was no difference in body fluid and urea withdrawal between groups. In the group of patients with no sleeping disturbances, the Charlson Comorbidity Index was significantly lower (p<0.001) than in patients with subclinical disorders or insomnia and emerged as a strongly associated with sleep disturbances. The study also attributes a predictive role to age, dialytic age, dialysis shift, antihypertensive drugs. The data indicate that, in evaluating sleeping disorders in patients on maintenance hemodialysis, comorbidities should be assessed.