C3-Epimer of 25-Hydroxyvitamin D3 as a Superior Marker for Predicting the Severity of Chronic Kidney Disease in Rheumatoid Arthritis Patients

Table 1

Comparison of observed indicators in RA patients with different CKD severity groups.

Indicator	Mild CKD ()	Moderate CKD ()	Severe CKD ()	,
Sex (male/female)^▲	53/194	17/29	8/17	5.850, 0.054
Age (years)				2.303, 0.102
25(OH)D (ng/ml)	19.55 (15.19, 24.84)	18.275 (14.83, 21.62)	16.72 (10.61, 21.54)	9.335, 0.009
25(OH)D2 (ng/ml)	1.55 (0.75, 4.96)	1.78 (0.58, 6.82)	2.17 (1.02, 5.59)	1.012, 0.603
25(OH)D3 (ng/ml)	16.36 (13.04, 20.97)	13.18 (8.81, 19.00)	12.22 (7.54, 17.61)	15.911, <0.001
F25(OH)D (ng/ml)	5.45 (4.20, 6.97)	5.13 (4.00, 6.10)	4.48 (2.98, 5.81)	8.792, 0.012
C3-epi-25(OH)D3 (ng/ml)	0.80 (0.50, 1.26)	1.24 (0.84, 1.72)	1.73 (1.34, 2.17)^#	48.302, <0.001
Cr (mol/l)	51.9 (44.4,60.1)	64.8 (53.3,74.9)	93.5 (86.7,120.8)^#	77.410, <0.001
CysC (mg/l)	0.97 (0.86,1.12)	1.42 (1.35,1.54)	1.92 (1.57,2.24)^#	165.496, <0.001
eGFR (ml/min/1.73m^2)	81 (70.1, 90.9)	55.8 (51.9, 58.1)	41.5 (37.0, 51.1)^#	159.598, <0.001
ACR (mg/g)	5.19 (3.14,9.79)	25.47 (12.76,40.11)	31.49 (13.80,146.81)	42.284, <0.001
hsCRP (mg/l)	12.85 (3.38, 36.46)	23.53 (8.05, 56.23)	27.72 (9.93, 59.17)	26.269, <0.001
RF (IU/ml)	101.5 (25.4, 336.0)	77.0 (11.2, 300.5)	136.5 (12.2, 313.0)	3.033, 0.220

Note: ^▲Crosstabs test of tabulations was used, and the rest were performed by Kruskal-Wallis test (nonnormal distribution) or one-way AVONA analysis (normal or nearly normal distribution). Severe or moderate vs. mild CKD group, ; ^#severe vs. moderate CKD group, . Among 25(OH)D metabolites, only C3-epi-25(OH)D3 levels had significant differences between any two groups of the three different CKD severity groups (all ).