Table 2. Cross-sectional correlation analyses between baseline serum sodium level and patient characteristics.

		Serum Na	Age	BMI	CCI	K	Albumin	Ferritin*	CRP*	Residual GFR*	PD UF	TotalKt/Vurea	nPCR	LBM
Serum Na	ρ	1	−0.047	0.072	−0.058	0.022	0.177	−0.133	0.006	0.211	−0.169	0.068	0.054	0.109
	p	-	0.329	0.129	0.223	0.640	<0.001	0.005	0.909	<0.001	<0.001	0.156	0.260	0.022
Age	ρ		1	−0.019	0.041	−0.133	−0.230	0.266	0.261	−0.058	−0.026	0.033	−0.165	−0.458
	p		−	0.695	0.695	0.005	<0.001	<0.001	<0.001	0.222	0.590	0.489	<0.001	<0.001
BMI	ρ			1	0.083	−0.007	0.021	0.024	−0.070	−0.039	0.026	−0.013	0.227	−0.046
	p			−	0.082	0.880	0.661	0.609	0.161	0.419	0.588	0.780	<0.001	0.333
CCI	ρ				1	0.021	−0.058	0.032	0.030	−0.044	0.126	−0.019	−0.020	0.021
	p				−	0.659	0.226	0.508	0.542	0.360	0.008	0.697	0.675	0.660
K	ρ					1	0.031	−0.140	−0.070	−0.003	0.121	−0.074	0.152	0.098
	p					-	0.510	0.003	0.162	0.958	0.574	<0.001	0.001	0.039
Albumin	ρ						1	-0.094	−0.096	0.145	−0.015	0.147	0.271	0.269
	p						-	0.048	0.053	0.002	0.754	0.002	<0.001	<0.001
Ferritin*	ρ							1	0.243	−0.246	0.129	−0.088	−0.152	−0.218
	p							-	<0.001	<0.001	0.007	0.066	0.001	<0.001
CRP*	ρ								1	-0.070	0.096	0.047	−0.114	−0.193
	p								-	0.158	0.055	0.342	0.022	<0.001
Residual GFR*	ρ									1	−0.365	0.533	0.238	0.376
	p									-	<0.001	<0.001	<0.001	<0.001
PD UF	ρ										1	0.065	0.067	0.027
	p										-	0.171	0.157	0.577
Total Kt/Vurea	ρ											1	0.451	0.293
	p											-	<0.001	<0.001
nPCR	ρ												1	0.464
	p												-	<0.001
LBM	ρ													1
	p													-

*Data for ferritin, CRP, and residual GFR were log-transformed.

BMI, body mass index; CCI, Charlson Comorbidity Index score; Na, sodium; K, serum potassium; tCO2, serum bicarbonate; CRP, C-reactive protein; GFR, glomerular filtration rate; PD UF, peritoneal dialysis ultrafiltration; nPCR, normalized protein, LBM, percentage of lean body mass.