Comparison of clinical characteristics between automated peritoneal dialysis and continuous ambulatory peritoneal dialysis: a 2-year single-center observational study

Figures & data

TABLE 1. Clinical demographic and biochemical data in patients receiving APD and CPAD

Patient characteristics	APD group (n = 32)	CAPD group (n = 140)	p-Value
Age (years)	45.4 ± 17.0	48.0 ± 12.8	0.42
Sex (M/F)	19/13	55/85	0.04
Causes of ESRD
Diabetes/nondiabetes	4/28	15/125	0.77
Body mass index	21.8 ± 3.5	22.2 ± 3.4	0.58
Biochemistry
Albumin (g/dL)	3.6 ± 0.4	3.7 ± 0.4	0.31
Hemoglobin (g/dL)	10.7 ± 1.9	10.6 ± 1.4	0.79
Total cholesterol (mg/dL)	171 ± 37	189 ± 45	0.07
LDL-cholesterol (mg/dL)	93 ± 27	110 ± 40	0.04
Triglyceride (mg/dL)	144 ± 165	142 ± 94	0.91
Calcium × phosphorus (mg^2/dL^2)	45.6 ± 13.1	48.7 ± 12.2	0.24
Ferritin (ng/mL)	370 ± 278	328 ± 289	0.46
Urine output (mL/day)	967 ± 409	1055 ± 649	0.35
ACEi and/or ARB	20 (63%)	84 (60%)	0.79
Statin	5 (16%)	50 (36%)	0.03
Residual renal function
Weekly urine CCr (L/week/1.73 m^2)	29.9 ± 17.1	32.9 ± 27.6	0.55
Peritoneal transport characteristics
Weekly total CCr (L/week/1.73 m^2)	71.5 ± 18.5	75.4 ± 25.9	0.42
Weekly total Kt/V	2.10 ± 0.42	2.24 ± 0.46	0.10
PET 4 h D/P (H/HA/LA/L)	0.65 ± 0.10 (1/16/11/3)	0.66 ± 0.10 (9/61/55/9)	0.68
nPCR	1.12 ± 0.29	1.15 ± 0.31	0.63

Notes: Data are expressed as mean ± SD and number (%), as appropriate. LDL, low-density lipoprotein; ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; CrCl, creatinine clearance; Kt/V, urea clearance in liters/liters total body water; PET 4 h D/P, the 4 h dialysate/plasma creatinine ratio evaluated by peritoneal equilibration test; H, high; HA, high-average; LA, low-average; L, low transporter; nPCR, normalized protein catabolic rate.

*Comparisons by unpaired t-test, Mann–Whitney U-test, and χ²-test, as appropriate.

TABLE 2. Incidences of infection complications in patients receiving APD and CAPD

	APD group (n = 32)	CAPD group (n = 140)	p-Value
Episodes of peritonitis within 2 years	10	48	0.74
Treatment duration (months)	46.1 ± 24.5	49.8 ± 26.1	0.44
Infectious complications
Episodes of peritonitis (per 100 patient-months)	21 (1.42)	86 (1.23)	0.41
Episodes of exit-site infection (per 100 patient-months)	13 (0.88)	52 (0.75)	0.67
Episodes of tunnel infection (per 100 patient-months)	5 (0.34)	3 (0.04)	0.04
Episodes of infectious complications (per 100 patient-months)	39 (2.64)	141 (2.02)	0.45

Notes: Data are expressed as mean ± SD and number (per 100 patient-months), as appropriate.

*Unpaired t-test for treatment duration; otherwise, Fisher's exact test and the χ²-test.

FIGURE 1. Kaplan–Meier survival analysis showed the similar mean interval to first episode of peritonitis for APD and CAPD.

TABLE 3. Comparison of peritoneal dialysis parameters in APD and CAPD patients at 6 months, 1 year, and 2 years

	Baseline APD	CAPD	At 6 months APD	CAPD	At 1 year APD	CAPD	At 2 years APD	CAPD
Urine weekly CrCl	29.9 ± 17.1	33.0 ± 27.6	13.0 ± 17.1	13.1 ± 18.4	19.5 ± 17.8	22.4 ± 22.3	15.1 ± 14.9	17.7 ± 19.0
Change of urine weekly CrCl (L/week/1.73 m^2)			−16.9 ± 18.8	−19.9 ± 23.3	−10.5 ± 14.1	−9.8 ± 13.8	−14.8 ± 18.8	−15.3 ± 19.2
Total weekly CrCl	71.5 ± 18.5	75.4 ± 25.9	60.4 ± 12.4	58.9 ± 15.3	67.8 ± 14.9	67.8 ± 19.8	63.8 ± 14.4	62.6 ± 16.9
Change of total weekly CrCl (L/week/1.73 m^2)			−11.1 ± 20.1	−16.4 ± 23.6	−3.6 ± 16.5	−7.6 ± 16.1	−7.7 ± 20.5	−12.7 ± 19.5
Total weekly Kt/V	2.09 ± 0.42	2.24 ± 0.46	2.22 ± 0.40	2.06 ± 0.34	2.21 ± 0.41	2.18 ± 0.39	2.25 ± 0.50	2.12 ± 0.40
Change of total weekly Kt/V			0.13 ± 0.50**	−0.18 ± 0.48	0.12 ± 0.48	−0.06 ± 0.38	0.16 ± 0.54**	−0.11 ± 0.42
PET 4 h D/P Cr	0.65 ± 0.10	0.66 ± 0.10	0.62 ± 0.12	0.63 ± 0.13	0.67 ± 0.13	0.66 ± 0.11	0.61 ± 0.12	0.64 ± 0.11
nPCR	1.12 ± 0.29	1.15 ± 0.31	1.04 ± 0.20	1.10 ± 0.25	1.08 ± 0.24	1.13 ± 0.29	1.09 ± 0.30	1.10 ± 0.28
Total dialysate volume (L/day)			7.47 ± 1.72	6.68 ± 1.38	9.36 ± 2.45**	7.03 ± 1.39	9.61 ± 2.13**	7.41 ± 1.46
Hypertonic dialysate volume (L/day)			0.75 ± 0.92	0.59 ± 0.84	1.06 ± 0.94	0.88 ± 0.92	0.91 ± 0.90	1.01 ± 0.94
Ultrafiltration volume (mL/day)			764 ± 409	744 ± 435	874 ± 455	838 ± 465	1086 ± 429	1015 ± 509

Notes: Data are expressed as mean ± SD; comparisons by Mann–Whitney U-test and unpaired t-test analysis, as appropriate. PET 4 h D/P Cr, the 4 h dialysate/plasma creatinine ratio evaluated by peritoneal equilibration test; nPCR, normalized protein catabolic rate.

*p < 0.05 and

**p < 0.01, as compared with CAPD patients.

TABLE 4. Comparisons of clinical characteristics based on gender

Variables	APD (n = 32)		CAPD (n = 140)
Gender	Man	Woman	Man	Woman
Number	19	13	55	85
Age (years)	48.2 ± 15.5	41.4 ± 19.0	49.6 ± 14.5	47.0 ± 11.6
Change of urine weekly CrCl	−19.9 ± 20.1	−7.3 ± 14.2	−21.1 ± 25.7	−11.5 ± 12.3^‡
Change of total weekly Kt/V	−0.03 ± 0.45	0.44 ± 0.56^†	−0.14 ± 0.41	−0.09 ± 0.43^§
	Man (n = 74)		Woman (n = 98)
Change of urine weekly CrCl	−20.8 ± 24.2		−11.0 ± 12.6^¶
Change of total weekly Kt/V	−0.11 ± 0.42		−0.02 ± 0.49

Notes: Data are expressed as mean ± SD. Comparisons by Mann–Whitney U-test analysis.

*Urine CrCl and Kt/V at the 2-year follow-up.

^†p < 0.05 as compared with APD, man group.

^‡p < 0.05 as compared with CAPD, man group.

^§p < 0.05 as compared with APD, woman group.

^¶p < 0.05 as compared with man group. Other comparisons not significant.

TABLE 5. Hospitalizations and hospitalized days within the first 2 years of PD

	APD group	CAPD group	p-Value
Hospitalizations, times	15	45	0.12
Hospitalized days	7.1 ± 3.6	12.9 ± 9.8	0.03

Notes: Data are expressed as mean ± SD.

*Comparisons by χ²-test and Mann–Whitney U-test, as appropriate.