Lower serum sodium level predicts higher risk of infection-related hospitalization in maintenance hemodialysis patients: an observational cohort study

Table 3 Predictors of infection-related hospitalization in the study population

	Univariate		Multivariate^a
	HR (95% CI)	p-value	HR (95% CI)	p-value
Serum sodium level
Categorical model
<138.0 mEq/L	3.20 (1.54–6.64)	0.002	2.36 (1.10–5.04)	0.027
138.0 – 140.0 mEq/L	2.07 (0.98–4.40)	0.058	2.11 (0.99–4.51)	0.054
>140.0 mEq/L	1 (ref)		1 (ref)
Continuous model (per 1 mEq/L)	0.86 (0.79–0.94)	<0.001	0.90 (0.81–0.99)	0.040
Age (per 5 years)	1.06 (0.95–1.18)	0.318
Female (vs male)	1.31 (0.78–2.22)	0.313
Body mass index (per 1 kg/m²)	0.99 (0.91–1.07)	0.711
Smoking history	1.52 (0.90–2.56)	0.120
Inability to ambulate or transfer	4.79 (2.61–8.80)	<0.001	2.10 (0.90–4.91)	0.086
Comorbid conditions
Diabetes mellitus	1.66 (0.99–2.80)	0.056
Hypertension	0.65 (0.28–1.51)	0.313
Cardiovascular disease	2.54 (1.51–4.27)	<0.001	2.21 (1.30–3.75)	0.003
Peripheral vascular disease	1.83 (0.66–5.07)	0.243
Cerebrovascular disease	1.65 (0.86–3.19)	0.135
Chronic liver disease	1.08 (0.49–2.39)	0.846
Cancer	1.01 (0.46–2.23)	0.976
Dialysis vintage (per 12 months)	0.98 (0.95–1.01)	0.242
IDWL (per 1% of body weight)	1.05 (0.86–1.28)	0.651
Vascular access
Fistula	1 (ref)		1 (ref)
Graft or catheter	4.08 (2.33–7.15)	<0.001	2.95 (1.57–5.55)	0.001
Laboratory data
Hemoglobin (per 1 g/dL)	0.80 (0.59–1.08)	0.140
Serum albumin (per 1 g/dL)	0.16 (0.07–0.37)	<0.001	0.47 (0.15–1.45)	0.186
Serum creatinine (per 1 mg/dL)	0.84 (0.76–0.92)	<0.001	0.97 (0.86–1.10)	0.654
Serum β2-microglobulin (per 5 mg/dL)	1.26 (1.01–1.57)	0.037

^aAdjustments in serum sodium level, all covariates, which were correlated with the outcome, with p < 0.001 at univariate analyses including inability to ambulate or transfer, cardiovascular disease, graft or catheter, serum albumin, and serum creatinine, and also determinants of baseline serum sodium level at multivariate linear regression analyses including cancer, IDWL, and hemoglobin.
Abbreviations: CI confidence interval, HR hazard ratio, IDWL intradialytic weight loss.

ISSN: 1471-2369