Table 2. Paraspinal muscle and IMAT measurements across BMI subgroups in young (20–39 years), middle-aged (40–59 years) and elderly (60–79 years) group.
| Age (years) | BMI (kg/m2) | CSAIMAT (cm2) | CSAmuscle (cm2) | IMAT% (%) |
|---|---|---|---|---|
| 20–39 (n=196) | Normal (n=125, 63.8%) | 2.84±1.23 | 37.58±5.28 | 7.04±3.00 |
| Overweight (n=46, 23.4%) | 3.39±1.27** | 41.80±6.00*** | 7.57±2.89 | |
| Obesity (n=25, 12.8%) | 4.91±4.32*** | 44.65±9.88*** | 9.78±7.25* | |
| 40–59 (n=228) | Normal (n=118, 51.8%) | 4.20±2.08 | 37.89±6.05 | 10.08±5.31 |
| Overweight (n=72, 31.6%) | 4.96±2.12** | 39.22±7.41 | 11.50±5.45* | |
| Obesity (n=38, 16.6%) | 6.08±2.92*** | 43.37±6.40*** | 12.12±4.97* | |
| 60–79 (n=92) | Normal (n=25, 27.2%) | 7.19±3.23 | 31.52±4.96 | 18.57±7.42 |
| Overweight (n=36, 39.1%) | 8.59±3.39 | 34.83±5.40* | 19.73±7.11 | |
| Obesity (n=31, 33.7%) | 11.00±4.42*** | 35.88±5.86** | 23.10±6.88* |
*P value <0.05, **P value <0.01, ***P value <0.001. P values were calculated using Kruskal-Wallis tests and LSD post-hoc correction. The normal BMI subgroup was defined as the reference group. BMI, body mass index; IMAT, Intermuscular adipose tissue; CSA, cross-sectional area. IMAT% referred to CSAIMAT / (CSAIMAT + CSAmuscle) as fatty infiltration ratio of muscle.