Table 2. Demographic characteristics and measurement outcomes of paraspinal muscles for the entire cohort and by sex.
| Variables | All (N=336) | Male (N=148) | Female (N=188) | P value |
|---|---|---|---|---|
| Age (years) | 42.56±12.76† | 43.91±13.40 | 41.50±12.19 | 0.22 |
| Height (m) | 1.66±0.10 | 1.73±0.08 | 1.61±0.07 | <0.001* |
| Body weight (kg) | 60.42±10.48 | 67.75±8.84 | 54.61±7.78 | <0.001* |
| BMI (kg/m2) | 21.80±1.88 | 22.69±1.40 | 21.10±1.94 | 0.06 |
| FSFMF (%) | 18.96±6.97 | 16.21±6.26 | 21.14±6.77 | <0.001* |
| FSFES (%) | 14.38±5.53 | 12.37±4.80 | 15.97±5.56 | <0.001* |
| FSFPM (%) | 1.40 (0.88–2.42)‡ | 1.22 (0.68–2.35) | 1.62 (0.95–2.57) | 0.12 |
| FSFTotal (%) | 12.39±4.79 | 10.34±4.08 | 14.02±4.71 | <0.001* |
†, mean ± standard deviation (all such values) for normally distributed data. ‡, median with interquartile range in parentheses (all such values) for nonnormally distributed data. *, statistical significance (P<0.05). P value indicates the male group versus the female group. BMI, body mass index; FSF, fat signal fraction; MF, multifidus; ES, erector spinae; PM, psoas major. FSFTotal indicates the fat signal fraction of the sum of the multifidus, erector spinae, and psoas major.