Alterations of bone mineral density, bone microarchitecture and strength in patients with ankylosing spondylitis: a cross-sectional study using high-resolution peripheral quantitative computerized tomography and finite element analysis

Table 1 Clinical characteristics and areal BMD of AS patients and non-AS subjects

Variable	AS patients	Non-AS subjects
Number	53	85
Men (%)	29 (55)*	25 (29)
Caucasians	40 (75)*	76 (89)
Age (years)	44 ± 12*	61 ± 8
Weight (kg)	75 ± 3	76 ± 2
Height (cm)	167 ± 2	164 ± 1
BMI (kg/m²)	27 (22–32)	27 (25–31)
Fragility fractures (%)	5 (9)	6 (11)
Corticosteroid use (%)	3 (6)	5 (6)
Bisphosphonate use (%)	4 (9)	13 (15)
DMARDs (%)	7 (13)	0 (0)
Total daily calcium intake (mg)	745 (456–1020)*	1045 (471–1539)
Use of supplemental vitamin D (%)^a	19 (36)	32 (38)
Hormone therapy (%)^b	0 (0)*	16 (19)
Areal BMD^c (g/cm²)
L1–L4	0.994 ± 0.179	0.988 ± 0.156
Total hip	0.904 ± 0.149	0.930 ± 0.123
Femoral neck	0.767 ± 0.142	0.756 ± 0.116
Distal 1/3 radius	0.740 ± 0.127	0.644 ± 0.170
Ultra distal radius	0.477 ± 0.078	0.418 ± 0.120
Low BMD/osteopenia (%)	18 (34)	37 (44)
Osteoporosis (%)	6 (11)	7 (8)

Data expressed as mean ± standard deviation, median (interquartile range) or number (% N) unless specified otherwise
^aAt least 1000 IU vitamin D
^bPostmenopausal women receiving hormone replacement treatment
^cIntergroup comparison of BMD was not performed between AS and non-AS subjects because of the differences in age and sex
*p <0.05
AS ankylosing spondylitis, BMD bone mineral density, BMI body mass index, DMARD disease-modifying antirheumatic drug

ISSN: 1478-6362