Changes in LDD phenotypes over time, by zygosity
| Monozygotic twins | Dizygotic twins | Comparing monozygotic and dizygotic | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Trait | Baseline score (SD) | Follow-up score (SD) | Change in mean score (SD) | Baseline score | Follow-up score | Change in mean score (SD) | p Value baseline | p Value follow-up | p Value change in trait |
| Disc height | 4.07 (2.58) | 6.39 (2.65) | 2.27 1.93 | 3.80 (2.44) | 6.52 (2.82) | 2.71 (2.14) | 0.25 | 0.63 | 0.03 |
| Disc signal | 6.21 (2.61) | 8.55 (2.13) | 2.31 2.25 | 5.65 (2.73) | 8.25 (1.98) | 2.62 (2.18) | 0.03 | 0.13 | 0.15 |
| Disc bulge | 2.15 (1.69) | 3.88 (2.37) | 1.65 (1.76) | 1.97 (1.63) | 4.01 (2.43) | 2.07 (2.00) | 0.24 | 0.55 | 0.02 |
| Anterior osteophytes | 1.40 (1.46) | 4.22 (2.68) | 2.72 2.40 | 0.99 (1.40) | 4.15 (2.70) | 3.16 (2.47) | <0.01 | 0.76 | 0.06 |
| LDD summary score | 13.84 (6.39) | 23.05 (6.88) | 8.95 4.27 | 12.41 (6.35) | 22.93 (7.53) | 10.55* (4.68) | 0.02 | 0.86 | <0.01 |
Mean summary scores for the individual traits over the five lumbar discs and SD are shown for baseline and follow-up scans, with mean change in score over the 10-year period of follow-up, and p values are shown for comparison between monozygotic and dizygotic twins at baseline, follow-up and for change in trait. Taken together, all traits' changes over 10 years were highly significant, each trait p<0.0001.
LDD, lumbar disc degeneration.