Effects of sleepiness on survival in Japanese hemodialysis patients: J-DOPPS study

Sleep disorder and poor sleep quality are common in chronic hemodialysis (HD) patients. They have been claimed as a cause of morbidity and mortality. The relationship between the degree of sleepiness and survival has not been studied. We studied the degree of sleepiness in 1,252 adult HD patients (age ≥20 years) recruited into the Dialysis Outcomes Practice Pattern Study in Japan (J-DOPPS III), using the Japanese version of the Epworth Sleepiness Scale (JESS) questionnaire. Demographic data were presented for three subgroups: low, intermediate, and high JESS score. Cox proportional hazard regression analysis was performed to estimate the independent effect of several variables on survival. The hazard ratio for mortality was 2.312 (95% CI 1.267-4.220; p = 0.006) for those with a high JESS score (vs. those with a low JESS score) after adjusting for age, vintage (length of time on HD), sex, diabetes, body mass index, cardiovascular disease, HD treatment regimen (time, frequency, and single-pool Kt/V), laboratory data (serum albumin, creatinine, and total cholesterol), and medication (antihypertensive drugs, erythropoietin, vitamin D, and phosphate binders). Patients ≥70 years of age with comorbid conditions (congestive heart failure, stroke, and diabetes) showed a significantly higher JESS score (≥16). The JESS score did not show interaction by age. Results showed that the degree of sleepiness is related to survival in Japanese HD patients, particularly in elderly patients.