Prevalence and Possible Risk Factors of Low Bone Mineral Density in Untreated Female Patients with Systemic Lupus Erythematosus

Table 3

Characteristics of SLE patients with normal and low BMD at lumbar spine and total hip.

Variable	Normal BMD	Low BMD
Demographic variables
Age^#	31.6 ± 8.9	33.9 ± 16.1	0.869
BMI^#	20.7 ± 3.5	20.3 ± 2.8	0.730
Clinical variables
Disease duration^#	24.1 ± 34.7	20.1 ± 34.5	0.895
Serum creatinine^#	54.6 ± 26.7	55.2 ± 20.3	0.651
Serum albumin^#	31.7 ± 5.8	32.3 ± 8.6	0.216
24-hour urine protein^#	0.56 ± 0.75	0.62 ± 1.02	0.586
Serum TC^#	3.3 ± 0.9	4.2 ± 1.8	0.007
Serum triglyceride^#	2.0 ± 1.1	2.0 ± 1.7	0.332
Serum LDL-c^#	1.9 ± 0.6	2.4 ± 1.2	0.055
ESR^#	56.1 ± 34.7	54.9 ± 33.0	0.948
CRP^#	10.8 ± 12.9	10.8 ± 12.7	0.963
Complement 3^#	0.57 ± 0.32	0.59 ± 0.33	0.892
Complement 4^#	0.10 ± 0.09	0.10 ± 0.09	0.909
SLEDAI^#	11.7 ± 6.0	10.8 ± 5.2	0.579
Bone metabolism variables
Serum 25-[OH]D^#	12.2 ± 7.8	11.8 ± 6.7	0.995
Serum calcium	2.0 ± 0.2	2.0 ± 0.2	0.978
Serum phosphate	1.2 ± 0.3	1.0 ± 0.3	0.715
PTH^#	34.8 ± 23.7	38.1 ± 21.3	0.342
OC^#	10.1 ± 5.5	11.2 ± 7.9	0.880
CTX^#	500.8 ± 357.8	633.7 ± 498.0	0.373

The Student -test; Mann-Whitney test.
BMD = bone mineral density; BMI = body mass index; TC = total cholesterol; LDL-c = low density lipoprotein cholesterol; ESR = erythrocyte sedimentation rate; CRP = C-reactive protein; SLEDAI = Systemic Lupus Erythematosus Disease Activity Index; 25-[OH]D = 25-hydroxyvitamin D; PTH = parathyroid hormone; OC = osteocalcin; CTX = C-terminal cross-linking telopeptide of type I collagen.