Table 2.

Crude analysis of factors associated with erythropoietin (EPO) levels

Factor	n	EPO (UI/ml), median (IQR)	P
Sex			0.2
men	245	9.3 (6.7–13.5)
women	91	8.9 (6.7–11.9)
Age (yr)			0.01
<50	91	8.5 (5.7–11.5)
50–59	76	8.9 (6.9–11.6)
60–69	73	10.5 (7.2–16.1)a
70–max	96	9.2 (7.0–12.7)
African origin			0.3
no	296	8.9 (6.7–12.6)
yes	25	9.9 (6.1–13.6)
Body mass index (kg/m2)			0.005
<25	136	8.6 (5.9–11.4)
25–30	138	9.3 (6.7–13.1)b
30–max	62	10.6 (7.6–15.7)c
Diabetes			0.002
no	247	8.8 (6.1–12.2)
with diabetic glomerulopathy	46	8.6 (6.8–12.1)
with other nephropathy types	43	11.4 (8.7–16.2)c
Iron index			0.02
normal	253	8.9 (6.3–12.7)
absolute iron deficiency	16	14.9 (9.0–19.8)a
functional iron deficiency	67	8.9 (7.0–11.8)
CRP			0.006
≤8 g/L	289	8.9 [6.3-12.7]
>8 g/L	40	10.8 [7.7-14.6]
Serum albumin (g/L)
in patient with mGFR ≥30 ml/min per 1.73 m2			0.003
≥40	124	8.5 (5.9–12.6)
<40	80	10.9 (7.6–14.0)
in patients with mGFR <30 ml/min per 1.73 m2			0.6
≥40	61	9.4 (6.5–13.0)
<40	71	8.3 (6.3–12.2)
PCR (mg/mmol)			0.2
<30	140	8.9 (5.9–12.7)
30–300	165	9.8 (7.05–13.5)
300-max	31	7.6 (6.1–10.5)
PTH (pg/ml)			0.3
<60	145	8.9 (6.7–11.9)
≥60	191	9.2 (6.7–14.1)
1-25OH2 vitamin D (pg/ml)			0.09
<20	214	9.6 (7.0–13.5)
≥20	121	8.7 (5.6–11.8)
Folate (ng/ml)			0.5
<8	141	9.4 (6.7–15.4)
≥8	175	8.9 (6.2–12.4)
ACE inhibitors/ARBs			0.6
no	71	9.4 (7.1–12.0)
yes	265	8.9 (6.5–13.2)

EPO, erythropoietin; IQR, interquartile range; mGFR, GFR measured by ⁵¹Cr-EDTA renal clearance; iron index, transferrin saturation (TSAT) ≥20% indicates normal iron profile, TSAT<20% and ferritin <40 ng/ml indicate absolute iron deficiency, TSAT <20% and ferritin ≥40 ng/ml indicate functional iron deficiency; CRP, C-reactive protein; BMI, body mass index; PCR, urinary protein/creatinine ratio; PTH, parathyroid hormone; ACE inhibitors/ARBs, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

^aP<0.01.

^bP<0.05.

^cP<0.001.