Factors Associated with Uremic Pruritus in Patients Undergoing Peritoneal Dialysis

Figures & data

Figure 1 Diagram of study design.

Abbreviations: PD, peritoneal dialysis; VAS, visual analog scale.

Figure 2 Body map for assessing sites of uremic pruritus and prevalence of uremic pruritus by body region. Regions: head and neck, chest and abdomen, back, upper limbs, and lower limbs.

Table 1 Patients’ Characteristics

Number			46
Age (years)			59.4 ± 14.7
Male sex (number, %)			31 (67.3)
Body mass index (kg/m^2)			23.5 ± 3.1
Peritoneal dialysis vintage (months)			29.2 ± 25.2
Peritoneal dialysis modality	CAPD (number, %)		15 (32.6)
	APD (number, %)		4 (8.7)
	CAPD and APD (number, %)		27 (58.7)
Peritoneal dialysis solution	Icodextrin solution (number, %)		29 (63.0)
	Lactate-buffered solution (number, %)		17 (37.0)
	Bicarbonate-buffered solution (number, %)		31 (67.4)
Weekly total Kt/V			1.7 ± 0.3
Weekly renal Kt/V			0.39 ± 0.35
Weekly peritoneal Kt/V			1.21 ± 0.33
Combined therapy with peritoneal dialysis and hemodialysis (number, %)			7 (15.2)
Diabetes mellitus (number, %)			19 (41.3)
Diabetic neuropathy (number, %)			3 (6.5)
Diabetic angiopathy (number, %)			5 (10.9)
Liver disease (number, %)			1 (2.2)
Corticosteroid (number, %)			1 (2.2)
Antihistamine (number, %)			9 (19.6)
Nalfurafine		2.5 μg/day (number, %)	7 (15.2)
		5.0 μg/day (number, %)	1 (2.2)
Topical medicine (moisturizer, topical corticosteroid) (number, %)			14 (30.4)
Calcium-containing phosphate binder (number, %)			26 (56.5)
Calcium-free phosphate binder (number, %)			35 (76.1)
Vitamin D analog (number, %)			29 (63.0)
Cinacalcet (number, %)			9 (19.6)
Polaprezinc (number, %)			5 (10.9)
Erythropoiesis-stimulating agent (number, %)			44 (95.7)
Visual analog scale score of itching at daytime			3.5 ± 2.7
Visual analog scale score of itching at nighttime			4.5 ± 3.3

Abbreviations: APD, automated peritoneal dialysis; CAPD, continuous ambulatory peritoneal dialysis.

Figure 3 Distribution of patients by VAS scores in the daytime (A) and nighttime (B).

Abbreviation: VAS, visual analog scale.

Figure 4 Comparison of uremic pruritus intensities in the daytime and nighttime.

Abbreviation: VAS, visual analog scale.

Table 2 Simple Linear Regression Analyses of the Variables Correlated with Uremic Pruritus Intensity in the Daytime

	Simple Linear Regression Analysis
Standard Coefficient	P-value
Age (years)	0.202	0.17
Male sex (yes vs. no)	0.310	0.036
Body mass index (kg/m^2)	0.080	0.60
Peritoneal dialysis vintage (months)	0.133	0.38
CAPD (yes vs. no)	0.120	0.43
APD (yes vs. no)	−0.191	0.20
CAPD and APD (yes vs. no)	−0.005	0.97
Icodextrin solution (yes vs. no)	−0.082	0.59
Lactate-buffered solution (yes vs. no)	0.022	0.88
Bicarbonate-buffered solution (yes vs. no)	−0.050	0.74
Weekly total Kt/V	−0.171	0.26
Weekly renal Kt/V	−0.170	0.26
Weekly peritoneal Kt/V	−0.082	0.59
Combined therapy with peritoneal dialysis and hemodialysis (yes vs. no)	0.273	0.06
Diabetes mellitus (yes vs. no)	0.180	0.23
Diabetic neuropathy (yes vs. no)	0.116	0.44
Diabetic angiopathy (yes vs. no)	0.184	0.22
Liver disease (yes vs. no)	−0.170	0.26
Corticosteroid (yes vs. no)	−0.113	0.45
Antihistamine (yes vs. no)	0.216	0.15
Nalfurafine (yes vs. no)	0.107	0.48
Topical medicine (yes vs. no)	0.185	0.22
Calcium-containing phosphate binders (yes vs. no)	0.178	0.24
Calcium-free phosphate binders (yes vs. no)	−0.007	0.96
Vitamin D analog (yes vs. no)	0.029	0.85
Cinacalcet (yes vs. no)	0.029	0.85
Polaprezinc (yes vs. no)	−0.068	0.66
Erythropoiesis-stimulating agent (yes vs. no)	−0.080	0.60
Hemoglobin A1c (%)	0.211	0.23
Total protein (g/dL)	−0.236	0.11
Serum albumin (g/dL)	−0.269	0.07
Blood urea nitrogen (mg/dL)	0.060	0.69
Creatinine (mg/dL)	0.056	0.71
Uric acid (mg/dL)	0.090	0.55
Sodium (mmol/L)	−0.028	0.85
Potassium (mmol/L)	−0.142	0.35
Chloride (mmol/L)	0.130	0.39
Calcium (mg/dL)	−0.203	0.18
Phosphate (mg/dL)	−0.040	0.79
Magnesium (mg/dL)	−0.021	0.89
Blood sugar (mg/dL)	0.235	0.12
Hemoglobin (g/dL)	0.004	0.98
Bicarbonate (mmol/L)	−0.174	0.25
Ferritin (ng/mL)	−0.046	0.76
β2 microglobulin (mg/L)	0.038	0.80
Intact-parathyroid hormone (pg/mL)	0.196	0.19

Abbreviations: APD, automated peritoneal dialysis; CAPD, continuous ambulatory peritoneal dialysis.

Table 3 Simple and Multiple Linear Regression Analyses of the Variables Correlated with Uremic Pruritus Intensity in the Nighttime

	Simple Linear Regression Analysis		Multiple Linear Regression Analysis
Standard Coefficient	P-value	Standard Coefficient	P-value
Age (years)	0.218	0.15
Male sex (yes vs. no)	0.191	0.20
Body mass index (kg/m^2)	0.035	0.82
Peritoneal dialysis vintage (months)	0.415	0.004	0.415	0.004
CAPD (yes vs. no)	0.210	0.16
APD (yes vs. no)	−0.023	0.88
CAPD and APD (yes vs. no)	−0.187	0.21
Icodextrin solution (yes vs. no)	−0.190	0.21
Lactate-buffered solution (yes vs. no)	0.079	0.60
Bicarbonate-buffered solution (yes vs. no)	0.019	0.90
Weekly total Kt/V	−0.017	0.91
Weekly renal Kt/V	−0.092	0.54
Weekly peritoneal Kt/V	−0.054	0.72
Combined therapy with peritoneal dialysis and hemodialysis (yes vs. no)	0.207	0.17
Diabetes mellitus (yes vs. no)	0.262	0.08
Diabetic neuropathy (yes vs. no)	0.069	0.65
Diabetic angiopathy (yes vs. no)	0.217	0.15
Liver disease (yes vs. no)	0.047	0.76
Corticosteroid (yes vs. no)	−0.161	0.29
Antihistamine (yes vs. no)	0.137	0.36
Nalfurafine (yes vs. no)	0.241	0.11
Topical medicine (yes vs. no)	0.345	0.019	0.345	0.019
Calcium-containing phosphate binders (yes vs. no)	0.261	0.08
Calcium-free phosphate binders (yes vs. no)	−0.073	0.63
Vitamin D analog (yes vs. no)	0.102	0.50
Cinacalcet (yes vs. no)	0.188	0.21
Polaprezinc (yes vs. no)	−0.204	0.17
Erythropoiesis-stimulating agent (yes vs. no)	−0.034	0.82
Hemoglobin A1c (%)	0.310	0.07
Total protein (g/dL)	−0.189	0.21
Serum albumin (g/dL)	−0.250	0.09
Blood urea nitrogen (mg/dL)	−0.106	0.48
Creatinine (mg/dL)	0.083	0.59
Uric acid (mg/dL)	0.010	0.95
Sodium (mmol/L)	0.014	0.92
Potassium (mmol/L)	0.045	0.77
Chloride (mmol/L)	0.162	0.28
Calcium (mg/dL)	−0.138	0.36
Phosphate (mg/dL)	0.099	0.51
Magnesium (mg/dL)	0.155	0.30
Blood sugar (mg/dL)	0.269	0.07
Hemoglobin (g/dL)	−0.123	0.42
Bicarbonate (mmol/L)	−0.132	0.39
Ferritin (ng/mL)	−0.181	0.23
β2 microglobulin (mg/L)	0.151	0.32
Intact-parathyroid hormone (pg/mL)	−0.091	0.55

Abbreviations: APD, automated peritoneal dialysis; CAPD, continuous ambulatory peritoneal dialysis.