Table 1.

Baseline characteristics of the cohort

Variable	Total cohort (n = 2606)	Serum ferritin category
		<50 ng/mL (n = 616)	50–99.9 ng/mL (n = 450)	100–199.9 ng/mL (n = 635)	≥200 ng/mL (n = 905)
Age (years)	64.0 (12.0)	62.9 (12.0)	62.7 (12.4)	64.4 (11.9)	65.0 (11.7)
Male (%)	62.1	63.0	60.2	58.9	64.6
Years on dialysis (years)	5.0 (1.6–10.3)	5.8 (2.2–10.7)	4.9 (1.30–10.4)	4.7 (1.2–10.4)	4.9 (1.5–10.1)
Diabetes (%)	38.7	33.0	39.3	38.0	42.9
Comorbidities of CVD (%)
CHF	25.7	25.7	25.6	23.9	27.0
CAD	37.5	37.0	37.3	35.0	39.6
Stroke	15.2	14.1	18.4	13.1	15.9
PAD	20.2	17.2	20.0	19.7	22.8
Others	33.7	30.4	33.1	32.1	37.4
Body mass index (kg/m2)	21.1 (3.3)	21.3 (3.3)	21.1 (3.4)	21.1 (3.3)	21.1 (3.3)
Alb (g/dL)	3.76 (0.42)	3.81 (0.41)	3.76 (0.41)	3.76 (0.40)	3.74 (0.43)
CRP (mg/dL)	0.12 (0.06–0.37)	0.12 (0.06–0.31)	0.10 (0.05–0.30)	0.10 (0.06–0.31)	0.15 (0.06–0.50)
Hb (g/dL)	10.4 (1.2)	10.4 (1.3)	10.5 (1.2)	10.4 (1.2)	10.3 (1.2)
Single pool Kt/V	1.35 (0.28)	1.38 (0.27)	1.34 (0.31)	1.34 (0.28)	1.34 (0.28)
ESA users (%)	92.0	90.0	93.2	92.0	92.7
Dose of ESA (103 units/month)	18.0 (9.0–28.5)	18.0 (11.3–36.0)	16.5 (9.8–26.4)	18.0 (9.0–24.0)	16.0 (9.0–27.0)
IV iron user (%)	30.0	24.7	32.0	30.5	32.1
Dose of IV iron (mg/month)	160 (160–320)	160 (160–320)	160 (160–480)	160 (160–480)	160 (160–240)

Values for categorical variables are given as percentage; values for continuous variables are given as mean (SD) or median (interquartile range). Dose of ESA was calculated only for ESA users and expressed as recombinant human erythropoietin (epoetin α or ß) using a conversion ratio of 1:200 for darbepoetin α. Dose of IV iron was also calculated only for IV iron users

Alb albumin, Hb hemoglobin, CRP C-reactive protein, CVD cardiovascular disease, CHF congestive heart failure, CAD coronary artery disease, PAD peripheral artery disease, ESA erythropoiesis-stimulating agent, IV intravenous