Table 4.
Longitudinal associations of IPFP signal measures with systemic biomarkers of bone turnover over 2 years
| IPFP SI measure | sCTX-I β (95% CI) | sNTX-I β (95% CI) | uCTX-Iα β (95% CI) | uCTX-1β β (95% CI) | uNTX-I β (95% CI) |
|---|---|---|---|---|---|
| Mean (IPFP) | 0.12 (0.05, 0.18)a | 0.05 (−0.00, 0.10) | 0.07 (0.01, 0.12) | 0.12 (0.05, 0.18)a | 0.13 (0.05, 0.20)a |
| sDev (IPFP) | 0.03 (−0.02, 0.08) | 0.03 (−0.01, 0.07) | 0.07 (0.01, 0.11) | 0.05 (−0.00, 0.10) | 0.07 (0.02, 0.12) |
| Median (H) | 0.10 (0.04, 0.16)a | 0.05 (0.00, 0.09) | 0.06 (0.01, 0.11) | 0.11 (0.04, 0.17)a | 0.07 (0.02, 0.12) |
| UQ (H) | 0.09 (0.03, 0.15)a | 0.04 (−0.00, 0.09) | 0.06 (0.01, 0.11) | 0.10 (0.03, 0.16)a | 0.06 (0.01, 0.12) |
| Percentage (H) | 0.04 (−0.01, 0.09) | 0.02 (−0.02, 0.07) | 0.06 (0.01, 0.12) | 0.03 (−0.03, 0.08) | 0.06 (0.01, 0.11) |
| Clustering factor (H) | 0.01 (−0.04, 0.06) | 0.01 (−0.03, 0.05) | −0.03 (−0.08, 0.02) | 0.00 (−0.05, 0.05) | −0.03 (−0.08, 0.02) |
With adjustment for baseline age, sex, body mass index, race, Kellgren/Lawrence grade, Western Ontario and McMaster Universities Osteoarthritis Index pain score, minimum joint space width, pain medication use, use of medications with effect on bone (parathyroid hormone in the past 6 months and bisphosphonate in the past 12 months).
There is an interaction between IPFP signal intensity measure and time. Bold values represent statistically significant associations, P < 0.05. CTX-I: C-terminal cross-linked telopeptide of type I collagen; IPFP: infrapatellar fat pad; Mean (IPFP): mean value of the whole IPFP signal intensity; Median (H): median value of high signal intensity; NTX-I: N-terminal cross-linked telopeptide of type I collagen; Percentage (H): ratio of volume of high signal intensity to volume of whole IPFP signal intensity; s: serum; sDev (IPFP): standard deviation of the whole IPFP signal intensity; u: urine; UQ (H): upper quartile value of high signal intensity.