Abstract P204: Insufficient Sleeping Time Was Associated With a High Risk For Sudden Cardiac Death and Excessive Sleeping Time Was Associated With a High Risk for Cerebrovascular Death Among Hemodialysis Patients
Authors: Ohsawa Masaki , Tanno Kozo , Itai Kazuyoshi , Kato Karen , Fujishima Yosuke , Onoda Toshiyuki , Okayama Akira , Sakata Kiyomi , Fujioka Tomoaki 
Published: July 2021

Background:
Inappropriate sleeping time contributes to an increased risk for death in general populations, however, whether inappropriate sleeping time contributes to an increased risk for death among hemodialysis patients has not been fully examined.

Methods:
A total of 1195 Japanese hemodialysis patients (769 men, 61.0 years of age; 426 women, 61.1 years of age) were enrolled. Participants were classified into 5 groups according to daily sleeping time: Group A (< 6 hours), Group B (6.0-6.9), Group C (7.0-7.9 (reference)), Group D (8.0-8.9), and Group E (9.0 hours and over). Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for cause-specific deaths (all-cause, cardiac, cerebrovascular, sudden cardiac, infectious disease) in each category compared with reference were estimated with adjustments for age, male sex, systolic blood pressure, total cholesterol levels, HDL cholesterol levels, HbA1c levels, serum albumin levels, serum C-reactive protein levels, smoking status, drinking habit, and comorbid conditions (myocardial infarction, stroke and malignant disease) using Cox's regression analysis.

Results:
A total of 444 patients died during the 5-year observation (4732.6 person-years, mean follow-up period of 3.96 years). Group A and E had significantly higher risks for all-cause death, Group D had a 2.6-fold higher risk for cerebrovascular death and Group A had a 2.5-fold higher risk for sudden cardiac death compared to references. (See
Table
)

Number of deaths, crude mortality rates and hazard ratios for cause-specific death

category
Group A (<6 hrs)
Group B (6-6.9 hrs)
Group C (7-7.9 hrs)
Group D (8-8.9 hrs)
Group E (>=9 hrs)

subjects (n)
155
213
262
271
294

all-cause death (mortality)
61 (101)
59 (65.8)
61 (54.9)
103 (96.2)
160 (152.5)

all-cause death HR (95% CI)
1.49 (1.03-2.16)
1.31 (0.91-1.89)
ref
1.34 (0.97-1.86)
1.64 (1.20-2.23)

cardiac death (mortality)
16 (26.4)
15 (16.7)
17 (15.3)
29 (27.1)
41 (39.1)

cardiac death HR (95% CI)
1.42 (0.71-2.87)
1.17 (0.58-2.34)
ref
1.39 (0.76-2.55)
1.62 (0.90-2.91)

cerebrovascular death (mortality)
9 (14.9)
5 (5.57)
6 (5.40)
18 (16.8)
17 (16.2)

cerebrovascular death HR (95% CI)
2.69 (0.95-7.62)
1.18 (0.36-3.88)
ref
2.61 (1.02-6.68)
2.24 (0.86-5.83)

sudden cardiac death (mortality)
20 (33.1)
13 (14.5)
12 (10.8)
21 (19.6)
33 (31.5)

sudden cardiac death HR (95% CI)
2.49 (1.15-5.38)
1.52 (0.67-3.47)
ref
1.48 (0.71-3.09)
1.82 (0.90-3.70)

infectious death (mortality)
11 (18.2)
15 (16.7)
24 (21.6)
26 (24.3)
41 (39.1)

infectious death HR (95% CI)
0.68 (0.33-1.42)
0.88 (0.46-1.70)
ref
0.82 (0.46-1.46)
0.91 (0.53-1.55)

Crude mortality rates are expressed as /1000 person-years.

Conclusion:
Insufficient sleeping time was associated with a high risk for sudden cardiac death and excessive sleeping time was associated with a high risk for cerebrovascular death among hemodialysis patients. More attention should be paid to appropriate sleeping time in hemodialysis patients to prevent cardiovascular death.