Table 3.

Linear regression analysis for the square root of serum hepcidin level.

	Univariable		Multivariable
	Beta (95% CI)	P	Beta (95% CI)	P
Age (years)	0.019 (0.012–0.025)	<0.001	−0.003 (−0.008–0.002)	0.310
Sex (men vs. female)	0.348 (0.183–0.513)	<0.001	−0.125 (−0.300–0.050)	0.160
Income (high vs. non-high)	−0.114 (−0.308–0.081)	0.252	—	—
Ever smoking (yes vs. no)	0.267 (0.106–0.429)	0.001	0.060 (−0.094–0.213)	0.447
SBP (mm Hg)	0.011 (0.006–0.016)	<0.001	0.002 (−0.001–0.006)	0.243
DBP (mm Hg)	−0.002 (−0.010–0.005)	0.536	—	—
BMI (kg/m2)	0.014 (−0.009–0.038)	0.236	—	—
Glucose (mmol/l)	0.038 (0.001–0.075)	0.042	−0.015 (−0.042–0.012)	0.284
eGFR (ml/min/1.73 m2)	−0.021 (−0.023–−0.018)	<0.001	−0.007 (−0.009–−0.004)	<0.001
Albumin (g/l)	−0.031 (−0.050–−0.012)	0.001	0.032 (0.015–0.049)	<0.001
Cholesterol (mmol/l)	−0.184 (−0.263–−0.105)	<0.001	−0.036 (−0.096–0.024)	0.239
WBC (×103/μl)	0.056 (0.014–0.098)	0.008	0.044 (0.012–0.077)	0.007
CRP (nmol/l)	0.229 (0.170–0.288)	<0.001	0.095 (0.051–0.139)	<0.001
UPCR (g/g)	0.160 (0.108–0.211)	<0.001	0.012 (−0.035–0.06)	0.607
Hemoglobin (g/dl)	−0.234 (−0.272–−0.195)	<0.001	−0.222 (−0.264–−0.181)	<0.001
Ferritin (pmol/l)	1.310 (1.243–1.377)	<0.001	1.226 (1.157–1.295)	<0.001
TSAT (%)	0.027 (0.020–0.034)	<0.001	0.011 (0.006–0.017)	<0.001
ESA use (yes vs. no)	1.951 (1.659–2.244)	<0.001	0.802 (0.563–1.041)	<0.001
Iron supplements (yes vs. no)	1.545 (1.327–1.763)	<0.001	0.306 (0.120–0.492)	0.001
Bilirubin (μmol/l)	−0.045 (−0.061–−0.030)	<0.001	0.012 (−0.002–0.026)	0.082

SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index; eGFR, estimated glomerular filtration rate; WBC, white blood cells; CRP, C-reactive protein; UPCR, urine protein-to-creatinine ratio; TSAT, transferrin saturation; ESA, erythropoiesis stimulating agents.

Logarithmic transformations were done for CRP, UPCR and ferritin. In multivariable linear regression analysis, variables with P < 0.05 in univariable linear regression analysis were chosen as covariates.