Table 1

Baseline characteristics of study population (n = 137)


Whole sample
No cartilage loss in any plate (at follow-up) (n = 66)
Cartilage loss in any plate (at follow-up) (n = 71)

Age in years, mean ± SD
67 ± 9
66 ± 9
67 ± 10
Males, number (percentage)
74 (54%)
38 (58%)
36 (51%)
Body mass index, mean (SD)
31.43 (5.48)
31.03 (6.08)
31.75 (4.87)
Percentage with K&L grade of ≥ 2
73%
67%
80%
Number of plates with cartilage loss, mean (SD)
0.99 (1.24)
0 (0)
1.92 (1.09)
Mean interval in years between baseline and follow-up scan
2.67
2.68
2.66
Levels of biomarkers, mean (SD)



     COMP
12.5 (2.9)
11.9 (2.9)
13.0 (2.9)
     846 epitope
269.3 (154.2)
273.4 (154.6)
265.4 (154.8)
     CPII
1,660.9 (598.5)
1,635.9 (623.9)
1,684.1 (577.3)
     C1,2C
0.06 (0.03)
0.06 (0.03)
0.06 (0.03)
     Col2CTX/Cr ratio
51.77 (63.53)
45.82 (31.81)
57.62 (83.70)
     C2C
53.2 (22.9)
57.0 (28.6)
49.7 (15.5)

C2C, collagenase cleavage of triple-helical type II collagen; Col2CTx, crosslinked peptides from the C-telopeptide domain of type II collagen; COMP, cartilage oligomeric matrix protein; CPII, C-propeptide of type II collagen; K&L, Kellgren & Lawrence; SD, standard deviation.

Hunter et al. Arthritis Research & Therapy 2007 9:R108   doi:10.1186/ar2314