Association of High Calcitriol Serum Levels and Its Hydroxylation Efficiency Ratio with Disease Risk in SLE Patients with Vitamin D Deficiency

Table 2

Clinical characteristics by renal activity in SLE patients.

Variable	Total	SLE patients		value
		Renal activity	No renal activity
Age (years)^a	33 (20–59)	32 (19–58)	33 (20–59)	0.44
Disease evolution time % ()				0.06
>5 years^b	48 (41/85)	33 (9/27)	55 (32/58)
SLICC ACR-DI^a	0 (0–04)	1 (0–5)	0 (0–3)	0.02
Damage (1)^b	39 (29/74)	56 (13/23)	31 (16/51)	0.04
Mex-SLEDAI^a	0 (0–8)	2 (0–8)	0 (0–7)	<0.01
Clinical disease activity (≥2)^b	38 (33/87)	58 (15/26)	30 (18/61)	0.01
Renal insufficiency^b	14 (12/83)	37 (10/27)	4 (2/56)	<0.001
Serum variables
ANAs (+)^b	94 (63/67)	96 (24/25)	93 (39/42)	0.60
Anti-dsDNA (+)^b	59 (36/61)	82 (18/22)	46 (18/39)	<0.01
C3 (mg/dL)^a	114 (55.3–150)	75 (55.3–120)	115 (1.17–156)	0.03
C4 (mg/dL)^c				0.43
Calcidiol reference values % ()				0.03
Sufficiency (≥30 ng/mL)^b	24 (20/82)	27 (7/26)	21 (13/61)
Insufficiency (≥20 to <30 ng/mL)^b	43 (35/82)	23 (6/26)	52 (32/61)
Deficiency (<20 ng/mL)^b	33 (27/82)	50 (13/26)	26 (16/61)
Calcitriol tertiles % ()				0.03
(≥48.7 to 157.3 pg/mL)^b	24 (21/88)	41 (11/27)	16 (10/61)
(≥33.6 to <48.7 pg/mL)^b	49 (43/88)	44 (12/27)	51 (31/61)
(0.33 to <33.6 pg/mL)^b	27 (24/88)	15 (4/27)	33 (20/61)
Calcitriol/calcidiol ratio tertiles % ()				0.26
(≥2.23 to 23.6 pg/ng)^b	29 (25/87)	38 (10/26)	25 (15/61)
(≥1.36 to ≤2.23 pg/ng)^b	41 (36/87)	42 (11/26)	41 (25/61)
(0.01 to <1.36 pg/ng)^b	30 (26/87)	19 (5/26)	34 (21/61)
Serum calcium (mg/dL)^c				0.43

^aData provided in medians (percentile: –), Mann–Whitney test. ^bData provided in percentages (/total patients), . ^cData provided in , Student -test. The bold letters indicate the variables with significant differences. SLICC: Systemic Lupus International Collaborating Clinics, American College of Rheumatology Damage Index; Mex-SLEDAI: Mexican Systemic Lupus Erythematosus Disease Activity Index; ANAs: antinuclear antibodies; Anti-dsDNA: anti-double-stranded DNA antibodies; C3 and C4: complement; GFR: glomerular filtration rate; G1: normal or high; G2: mildly decrease; G3a: mildly to moderately decrease; G3b: moderately to severely decrease; G4: severely decreased; G5: kidney failure.