Table 1. General and clinical features of the population studied, according to bone mineral density (BMD).
| Variable | Normal BMD | Osteopenia BMD | Osteoporosis BMD | P |
|---|---|---|---|---|
| n = 24 | n = 38 | n = 21 | ||
| Mean (SD) | Mean (SD) | Mean (SD) | ||
| Age (years) | 49.9 ± 9.6 | 52.1 ± 9.4 | 61.0 ± 7.8 *† | < 0.001 |
| Disease duration (years) | 5.1 ± 4.5 | 8.0 ± 7.6 | 10.2 ± 5.5 *† | 0.030 |
| BMI (kg/m2) | 29.6 ± 5.7 | 26.8 ± 4.9 | 23.4 ± 3.6*† | < 0.001 |
| DAS-28 (score) | 4.8 ± 1.3 | 4.9 ± 1.2 | 4.5 ± 1.3 | 0.498 |
| HAQ (score) | 0.9 ± 0.7 | 1.1 ± 0.8 | 0.8 ± 0.7 | 0.368 |
| Work index (score) | 3.1 ±0.5 | 2.9 ± 0.5 | 2.6 ± 0.5 | 0.125 |
| Sport index (score) | 2.2 ± 0.6 | 2.0 ± 0.6 | 2.0 ± 0.5 | 0.273 |
| Leisure index (score) | 7.4 ± 1.5 | 6.7 ± 1.4 | 7.0 ± 1.8 | 0.326 |
| Total physical activity index (score) | 12.8 ± 1.9 | 11.7 ± 1.8 | 11.7 ± 2.2 | 0.171 |
| Current prednisone (mg) | 5.7 ± 4.7 | 5.7 ± 3.0 | 4.8 ± 3.4 | 0.586 |
| Cumulative prednisone (mg) | 2706.3 ± 2121.3 | 4219.0 ± 2272.8‡ | 3631.8 ± 2102.6 | 0.034 |
| Lumbar spine BMD (g/cm2) | 1.202 ± 0.098 | 1.019 ± 0.102‡ | 0.852 ± 0.096*† | < 0.001 |
| Femoral neck BMD (g/cm2) | 1.037 ± 0.119 | 0.847 ± 0.082‡ | 0.657 ± 0.085*† | < 0.001 |
| Total femur BMD (g/cm2) | 1.066 ± 0.110 | 0.879 ± 0.079‡ | 0.678 ± 0.078*† | < 0.001 |
| Total fat-free mass (g) | 44471.7 ± 4839.5 | 41407.7 ± 5157.2‡ | 37194.3 ± 4162.7*† | < 0.001 |
| Appendicular lean mass (kg) | 20934.6 ± 2489.8 | 19272.8 ± 2752.7‡ | 16404.4 ± 2516.8*† | < 0.001 |
| RSMI (kg/m2) | 8.6 ± 0.9 | 8.0 ± 1.1 | 7.4 ± 0.9*† | < 0.001 |
| Body fat (%) | 34.6 ± 7.4 | 32.4 ± 8.0 | 28.3 ± 6.7* | 0.008 |
*P < 0.05 versus normal BMD; †P < 0.05 versus osteopenia BMD; ‡P < 0.05 versus osteoporosis BMD; DAS-28 = Disease activity score 28; HAQ = Health Assessment Questionnaire; BMI = Body mass index; RSMI = Relative Skeletal Muscle Index; ANCOVA (analysis of covariance) = adjustments for age, disease duration and cumulative prednisone; SD = standard deviation.