TABLE 1.
Basic characteristics by presence of MC on the MRI.
| n = 326 | n = 100 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| MC | % | noMC | % | p | MC | % | noMC | % | p | |
| Total | 158 | 48.5 | 168 | 51.5 | 49 | 49 | 51 | 51 | ||
| MC1 | 157 | 99.4 | ‐ | ‐ | 49 | 100 | ‐ | ‐ | ||
| MC2 | 145 | 91.8 | ‐ | ‐ | 44 | 89 | ‐ | ‐ | ||
| MC3 | 1 | 0.6 | ‐ | ‐ | 1 | 2 | ‐ | ‐ | ||
| More than one MC type | 142 | 89.9 | ‐ | ‐ | 44 | 89 | ‐ | ‐ | ||
| Average Pfirrmann score sum L1‐S1 | 14.82 | 12.46 | <0.0001 | 14.79 | 12.35 | <0.0001 | ||||
| Average days between serum sampling and MRI | 366.5 | 367.9 | 0.89 | |||||||
| Sex: female | 90 | 56.9 | 115 | 68.4 | 0.03 | 28 | 57.1 | 32 | 62.4 | 0.43 |
| cLBP | 42 | 26.6 | 47 | 28.0 | 0.82 | 24 | 48.9 | 24 | 47.1 | 0.76 |
| Unknown pain status | 13 | 8.2 | 12 | 7.1 | 2 | 4.1 | 1 | 2.0 | ||
| Average BMI (kg/m2) | 26 | 26.1 | 0.99 | 26.9 | 27.3 | 0.57 | ||||
| Overweight | 83 | 52.5 | 94 | 56.0 | 0.6 | 31 | 63.2 | 37 | 72.5 | 0.24 |
| Unknown BMI | 2 | 1.2 | 2 | 1.2 | 0 | 0 | 1 | 2.0 | ||
| Smoking ever regularly | 81 | 51.3 | 95 | 56.6 | 0.25 | 29 | 59.2 | 30 | 58.8 | 0.84 |
| Unknown if ever smoking | 1 | 0.6 | 4 | 2.3 | 0 | 0 | 2 | 3.9 | ||
| Smoking currently regularly | 28 | 17.7 | 21 | 12.5 | 0.74 | 8 | 16.3 | 6 | 11.8 | 0.69 |
| Unknown current smoking status | 6 | 3.8 | 16 | 9.5 | 1 | 2 | 7 | 13.7 | ||
| Comorbidities | ||||||||||
| Diabetes type 1 | 3 | 1.9 | 2 | 1.2 | 0.68 | 1 | 2.0 | 0 | 0 | 1.00 |
| Diabetes type 2 | 2 | 1.3 | 4 | 2.4 | 0.68 | 0 | 0 | 1 | 2.0 | 0.48 |
| Unknown if diabetes | 2 | 1.3 | 7 | 4.1 | 2 | 4.1 | 7 | 13.7 | ||
| Coronary heart disease | 4 | 2.5 | 0 | 0 | 0.054 | 2 | 4.1 | 0 | 0 | 0.49 |
| Unknown if coronary heart disease | 3 | 1.9 | 3 | 1.8 | 1 | 2.0 | 4 | 7.8 | ||
| Emphysema/chronic bronchitis | 4 | 2.5 | 1 | 0.6 | 0.21 | 1 | 2.0 | 0 | 0 | 0.49 |
| Unknown if emphysema/chronic bronchitis | 8 | 5.6 | 11 | 6.5 | 2 | 4.1 | 6 | 11.8 | ||
| Osteoporosis | 3 | 1.9 | 1 | 0.6 | 0.36 | 0 | 0 | 1 | 2.0 | 1.00 |
| Unknown if osteoporosis | 3 | 1.9 | 3 | 1.8 | 1 | 2.0 | 3 | 5.9 | ||
| Cancer | 6 | 3.8 | 5 | 3 | 0.76 | 0 | 0 | 1 | 2.0 | 1.00 |
| Unknown if cancer | 3 | 1.9 | 4 | 2.4 | 3 | 6.1 | 4 | 11.8 | ||
Note: On the left: The sample of 326 participants is shown; on the right: The subset of 100 participants for the mass spectrometry study. Overweight = BMI>25 kg/m2. Smoking ever regularly = at least 1 cigarette on at least 5 days/week during at least 1 year; smoking currently regularly = at least 1 cigarette on at least 5 days/week. p = p‐value of either the chi‐square test, for the comorbidities (due to frequency of comorbidities below 5) Fisher's exact test or, for BMI, average Pfirrmann score and “days between serum sampling and MRI”, Mann–Whitney U‐test comparing MC and noMC.