Characteristics of the study participants
| Characteristics | CTX-I dataset (n=97) | CTX-II dataset (n=104) | RANKL:OPG dataset (n=100) | CTX-I + RANKL:OPG dataset (n=67) | CTX-II + RANKL:OPG dataset (n=73) |
|---|---|---|---|---|---|
| At baseline | |||||
| Age, years | 50 (12) | 50 (12) | 49 (13) | 49 (13) | 49 (13) |
| % Female | 59 | 59 | 59 | 55 | 56 |
| Disease duration (months) | 6 (5) | 5 (5) | 5 (5) | 5 (5) | 5 (5) |
| ESR | 52 (33) | 52 (32) | 52 (31) | 49 (30) | 49 (30) |
| HAQ score (range 0–3) | 1.4 (0.7) | 1.4 (0.7) | 1.5 (0.7) | 1.4 (0.7) | 1.5 (0.7) |
| CTX-I (ln) | 5.2 (0.6) | NA | NA | 5.2 (0.6) | NA |
| CTX-I | 209 (109) | NA | NA | 146 (102) | NA |
| CTX-II (ln) | NA | 5.8 (0.8) | NA | NA | 5.8 (0.8) |
| CTX-II | NA | 462 (419) | NA | NA | 471 (454) |
| RANKL (mean (SD) median) | 1477 (5621) 373 | 1394 (5394) 364 | 1274 (4648) 373 | 1477 (5621) 373 | 1394 (5394) 364 |
| OPG (mean (SD) median) | 372 (128) 374 | 378 (125) 381 | 388 (129) 389 | 372 (128) 374 | 379 (126) 381 |
| RANKL:OPG ratio (ln) | NA | NA | −0.3 (1.8) | −0.2 (1.8) | −0.3 (1.9) |
| RANKL:OPG ratio | NA | NA | 3.5 (9.3) | 4.2 (11.2) | 3.9 (10.8) |
| % Rheumatoid factor positive | 74 | 73 | 70 | 67 | 66 |
| % With baseline radiological damage | 77 | 77 | 76 | 75 | 74 |
| Baseline radiological damage (mean SvH (SD) median) | 9 (13) 3 | 9 (13) 3 | 8 (11) 3 | 8 (12) 3 | 8 (11) 3 |
| Annual radiological progression (mean SvH (SD) median)(ln) | 1.5 (0.9) 1.5 | 1.5 (0.9) 1.5 | 1.5 (1.0) 1.5 | 1.4 (0.9) 1.4 | 1.4 (0.9) 1.4 |
| Annual radiological progression (mean SvH (SD) median) | 5.4 (0.6) 3.5 | 5.4 (0.6) 3.5 | 5.7 (0.7) 3.5 | 4.8 (0.6) 3.1 | 5.0 (0.7) 3.0 |
| At 3-month follow-up | |||||
| ESR | 20 (18) | 21 (20) | 22 (22) | 19 (17) | 19 (17) |
| CTX-I (ln) | 4.7 (0.8) | NA | NA | 4.7 (0.8) | NA |
| CTX-I | 148 (104) | NA | NA | 146 (102) | NA |
| CTX-II (ln) | NA | 5.3 (0.8) | NA | NA | 5.4 (0.8) |
| CTX-II | NA | 292 (252) | NA | NA | 278 (213) |
RANKL and OPG in pmol/l; CTX-I expressed as μg/mmol of urinary creatinine and CTX-II as ng/mmol of urinary creatinine; these and the RANKL:OPG ratio and annual radiological progression are presented as true values as well as log (ln) transformed values. Mean (SD) unless stated otherwise.
CTX-I and CTX-II, C-terminal cross linking of type-I and type-II; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; OPG, osteoprotegerin; RANKL, receptor activator of nuclear factor-κB ligand; SvH, Sharp/van der Heijde score.