Table 1.

Anthropometric characteristics and serum levels of bone turnover markers

	Osteoporosis	Osteoarthritis
Age (years)	74.1 ± 7.7	71.8 ± 4.2
Sex (women/men)	17/6	23/8
Body mass index (kg/m2)	24.5 ± 2.3	28.3 ± 4.4**
Hip bone mineral density (g/cm2)	0.726 ± 0.135	0.880 ± 0.140**
Femoral neck BMD (g/cm2)	0.615 ± 0.098	0.757 ± 0.131**
Lumbar spine L2-L4 BMD (g/cm2)	0.861 ± 0.184	0.994 ± 0.193*
CTX (pmol/l)	3078(1285;5391)	3547(2183;4967)
Osteocalcin (μg/l)	6.80(0.30;11.98)	7.90(1.03;17.03)
Cathepsin K (pmol/l)	12.0(10.0;22.1)	9.4(6.7;11.3)*
RANKL (pmol/l)	0.01(0.01;0.02)	0.01(0.01;0.06)
OPG (pmol/l)	5.86(4.52;7.47)	4.42(4.09;5.01)*

BMD bone mineral density. CTX C-terminal crosslinking telopeptides of type I collagen. RANKL receptor activator of nuclear factor κB ligand.

OPG osteoprotegerin.

Values are means ± standard deviation (with the exception of sex) and medians(25th;75th quartile) for bone turnover markers.

Comparisons were assessed with Student's t-test or Mann-Whitney U test, *p < 0.05, **p < 0.001.