Urine 5MedC, a Marker of DNA Methylation, in the Progression of Chronic Kidney Disease

Table 1

Baseline characteristics of the study subjects divided by CKD stages.

	All patients	Early to Mid-CKD (stages 1 to 3)	Later CKD (stages 4 and 5)	value
N	308	241	67
Age (years)	56 (37-67)	52 (35-65)	62 (55-71)	<0.0001
Gender, male, n (%)	164 (53.2)	123 (51.0)	41 (61.2)	0.139
eGFR (ml/min/1.73 m^2)	55.4 (32.0-79.6)	63.8 (47.9-85.8)	18.6 (14.2-24.3)	<0.0001
UAE (mg/gCr)	158 (20-762)	89 (12-542)	705 (126-1431)	<0.0001
uα1MG (mg/gCr)	5.7 (2.1-14.1)	3.9 (1.7-8.5)	23.5 (11.8-48.7)	<0.0001
u5MedC (μmol/gCr)	65.9 (40.8-130.3)	59.7 (39.0-116.5)	88.3 (48.5-153.9)	0.025
Hemoglobin (g/L)	130 (116-142)	133 (123-146)	112 (101-129)	<0.0001
MBP (mmHg)	91 (84-99)	91 (83-99)	96 (85-103)	0.013
Cause of CKD, n (%)				<0.0001
Chronic GN	157 (51.0)	146 (60.6)	11 (16.4)
Nephrosclerosis	40 (13.0)	19 (7.9)	21 (31.3)
Diabetic nephropathy	11 (3.6)	7 (2.9)	4 (6.0)
Others	100 (32.5)	69 (28.6)	31 (46.3)
Diabetes mellitus, n (%)	36 (11.7)	27 (11.2)	9 (13.4)	0.615
Current medication, n (%)
ARBs/ACEIs	196 (63.0)	137 (56.9)	59 (88.1)	<0.0001
CCBs	117 (38.0)	72 (29.9)	45 (67.2)	<0.0001

Data are expressed as the median (interquartile) or number (percentage). α1MG, alpha1-microglobulin; ARB, angiotensin receptor blocker; ACEI, angiotensin-converting enzyme inhibitor; CCB, calcium channel blocker; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; GN, glomerulonephritis; MBP, mean blood pressure; UAE, urinary albumin excretion; uα1-MG, urinary α1-microglobulin; u5MedC, urinary 5-methyl-2’-deoxycytidine. Chronic glomerulonephritis includes 93 cases (59.2%) of IgA nephropathy, 22 cases (14.0%) of minimal change nephrotic syndrome, 12 cases (7.6%) of membranous nephropathy, 12 cases (7.6%) of IgA vasculitis with nephritis, 7 cases (4.5%) of focal segmental glomerulosclerosis, 6 cases (3.8%) of non-IgA mesangial nephritis, 4 cases (2.6%) of membranoproliferative glomerulonephritis and 1 case (0.6%) of acute glomerulonephritis (persistent and chronic phase). Others include 62 cases (62.0%) of unknown etiology without a renal biopsy; 20 cases (20.0%) of lupus nephritis; 10 cases (10.0%) of anti-neutrophil cytoplasmic antibody-associated vasculitis; 3 cases (3.0%) of polycystic kidney disease; 2 cases (2.0%) of Alport syndrome; and 1 case each (1.0%) of thin basement membrane disease, cholesterol crystal embolization, and vesicoureteral reflux.