Predictors of poor sleep quality and excessive daytime sleepiness in peritoneal dialysis patients

Figures & data

Table 1. Characteristics of peritoneal dialysis patients recruited in the cross-sectional study.

Parameters	PD patients
Age, years	57.12 ± 14.90
Male/female	55/43
Duration of PD, months	16 (1026.50)
BMI, kg/m^2	23.60 ± 3.67
Hemoglobin, g/L	104.57 ± 22.44
Serum albumin, g/L	34.29 ± 4.61
BUN, mmol/L	19.12 ± 7.01
Creatinine, μmol/L	808.82 ± 338.15
Corrected calcium, mmol/L	2.36 ± 0.24
Phosphate, mmol/L	1.96 ± 0.69
Ca × P product, mg^2/dL^2	54.49 ± 19.79
Magnesium, mmol/L	0.95 ± 0.24
Total cholesterol, mmol/L	4.73 ± 1.25
Triglyceride, mmol/L	1.95 ± 1.13
HDL cholesterol, mmol/L	0.99 ± 0.36
LDL cholesterol, mmol/L	2.77 ± 0.97
TSAT,%	29.72 ± 14.82
Ferrtin, ng/mL	357.55 (198.55–590.53)
Intact-PTH, pg/mL	186.15 (82.20–447.23)
hs-CRP, mg/L	3.22 (3.22–5.43)
Total Kt/V	2.04 ± 0.47
Kt/V PD	1.56 ± 0.42
KRU	0.49 ± 0.40
NPCR (g/kg/day)	0.88 ± 0.24
Global PSQI	9.06 ± 4.60
ESS	6.31 ± 4.98

Notes: Data expressed as mean ± SD or as median (first, third quartile), as appropriate. PD, peritoneal dialysis; HDL cholesterol, high-density lipoprotein cholesterol; LDL cholesterol, low-density lipoprotein cholesterol; TSAT, transferrin saturation; PTH, parathyroid hormone; hs-CRP, high-sensitivity C-reactive protein; nPCR, normalized protein catabolic rate; total Kt/V, total weekly Kt/V urea; Kt/V PD, peritoneal Kt/V; KRU, urinary Kt/V.

Statistical significance was set at p < 0.05.

Table 2. Characteristics of groups with different sleep quality among the 98 PD patients.

	PSQI			ESS
Variables	≤5	>5	p Value	<9	≥9	p Value
Score	3.50 ± 1.38	10.86 ± 3.72	<0.001*	4.21 ± 2.59	13.55 ± 4.46	< 0.001*
Age, years	54.00 ± 11.53	58.14 ± 15.84	0.409	58.26 ± 15.34	53.18 ± 13.10	0.324
Male/female	15/10	40/33		41/35	14/8
Duration of PD, months	20	23	0.655	19	22	0.601
BMI, kg/m^2	23.26 ± 3.07	23.71 ± 3.88	0.712	23.56 ± 3.76	23.73 ± 3.54	0.894
Hemoglobin, g/L	99.75 ± 22.12	106.14 ± 22.62	0.397	104.42 ± 22.16	105.09 ± 244.51	0.932
Serum albumin, g/L	34.50 ± 4.60	34.22 ± 4.67	0.855	34.21 ± 4.30	34.55 ± 5.77	0.834
BUN, mmol/L	21.62 ± 9.46	18.37 ± 5.96	0.165	18.18 ± 6.99	22.57 ± 6.16	0.066
Creatinine, μmol/L	819.82 ± 367.29	831.70 ± 333.48	0.918	776.16 ± 323.12	1010.73 ± 340.03	0.041*
Corrected calcium, mmol/L	2.32 ± 0.26	2.37 ± 0.23	0.542	2.34 ± 0.23	2.41 ± 0.25	0.371
Phosphate, mmol/L	2.09 ± 0.87	1.91 ± 0.63	0.444	1.90 ± 0.70	2.17 ± 0.65	0.252
Ca × P product, mg^2/dL^2	56.76 ± 21.67	53.75 ± 19.40	0.652	52.36±19.79	61.84 ± 18.81	0.164
Magnesium, mmol/L	0.97 ± 0.22	0.94 ± 0.26	0.696	0.91 ± 0.18	1.09 ± 0.37	0.034*
Total cholesterol, mmol/L	4.53 ± 1.12	4.80 ± 1.30	0.531	4.79 ± 1.34	4.55 ± 0.94	0.582
Triglyceride, mmol/Ll	2.02 ± 0.94	1.63 ± 1.19	0.352	1.93 ± 0.78	2.01 ± 1.97	0.843
HDL cholesterol, mmol/L	0.89 ± 0.25	1.02 ± 0.38	0.263	0.99 ± 0.53	0.99 ± 0.39	0.975
LDL cholesterol, mmol/L	2.54 ± 1.02	2.85 ± 0.95	0.345	2.86 ± 1.03	2.48 ± 0.62	0.260
TSAT,%	26.44 ± 9.46	30.71 ± 16.08	0.409	28.95 ± 13.35	32.53 ± 19.94	0.504
Ferrtin, ng/mL	334.50 (153.31–833.73)	357.55 (206.63–582.13)	0.728	332.90 (153.05–508.35)	575.45 (442.70–947.25)	0.010*
Intact-PTH, pg/mL	271.00 (93.59–454.78)	168.30 (66.43–446.95)	0.627	172.30 (78.49–468.75)	315.90 (61.65–424.50)	0.870
hs-CRP, mg/L	3.22 (3.22–3.77)	3.59 (3.22–5.81)	0.301	3.22 (3.22–4.79)	4.33 (3.00–6.08)	0.795
Total Kt/V	1.97 ± 0.47	2.07 ± 0.47	0.530	2.11 ± 0.39	1.85 ± 0.66	0.126
Kt/V PD	1.39 ± 0.39	1.62 ± 0.42	0.138	1.56 ± 0.30	1.54 ± 0.70	0.867
KRU	0.58 ± 0.43	0.47 ± 0.39	0.046*	0.59 ± 0.40	0.31 ± 0.30	0.037*
nPCR (g/kg/day)	0.87 ± 0.17	0.88 ± 0.27	0.909	0.88 ± 0.25	0.88 ± 0.22	0.997

Note: Statistical significance was set at *p < 0.05.

Figure 1. Correlation between Pittsburgh Sleep Quality Index and urinary Kt/V (KRU) (A), Epworth Sleepiness Scale (B) and urinary Kt/V (KRU).

Table 3. Variables correlation with global PSQI score and ESS score.

	PSQI		ESS
Variables	r	p	r	p
Age, years	0.092	0.530	−0.118	0.421
Duration of PD, months	0.091	0.534	0.047	0.749
BMI, kg/m^2	0.071	0.627	−0.017	0.910
Hemoglobin, g/L	−0.199	0.170	0.273	0.057
Serum albumin, g/L	−0.107	0.464	0.346	0.015*
Creatinine, μmol/L	0.103	0.483	−0.045	0.670
Corrected calcium, mmol/L	0.497	0.099	0.144	0.325
Phosphate, mmol/L	0.102	0.486	0.313	0.029*
Ca × P product, mg^2/dL^2	0.099	0.497	0.335	0.019*
Magnesium, mmol/L	0.034	0.818	0.376	0.008*
Total cholesterol, mmol/L	0.169	0.246	−0.026	0.860
Triglyceride, mmol/Ll	0.786	0.078	0.089	0.543
HDL cholesterol, mmol/L	0.034	0.818	−0.066	0.654
LDL cholesterol, mmol/L	0.045	0.761	−0.067	0.649
TSAT,%	0.009	0.953	−0.045	0.764
Ferrtin, ng/mL	0.127	0.421	0.244	0.102
Intact-PTH, pg/mL	−0.028	0.852	−0.047	0.757
hs-CRP, mg/L	0.019	0.899	0.134	0.392
Total Kt/V	−0.150	0.336	−0.201	0.202
Kt/V PD	0.179	0.262	0.083	0.606
KRU	−0.392	0.032*	−0.341	0.029*

Note: Statistical significance was set at *p < 0.05.

Table 4. Multivariable linear regression analysis for the global PSQI score and ESS score.

Variables	β Value	p Value
PSQI
KRU	−0.406	0.029*
ESS	0.546	<0.001*
ESS
KRU	−0.296	0.047*
Magnesium	0.314	0.019*
PSQI	0.496	<0.001*

Note: Statistical significance was set at *p < 0.05.