Table 1. Association of Low Bone Mass with Demographic and Anthropometric Characteristics and Biochemical Profiles.
| Variables | Lumbar BMD | Femoral BMD | ||||
|---|---|---|---|---|---|---|
| Normal | Low | P value | Normal | Low | P value | |
| Age, y | 13.8 ± 2.7 | 13.5 ± 2.6 | 0.32 | 13.7 ± 2.6 | 14.2 ± 2.9 | 0.2 |
| BMI, kg/m 2 | 18.1 ± 3.2 | 16.1 ± 2.4 | < 0.001 | 17.8 ± 3.2 | 16.7 ± 2.9 | 0.015 |
| BMI-Z score | -0.5 ± 1.1 | -1.4 ± 1.5 | < 0.001 | -0.6 ± 1.2 | -1.4 ± 1.4 | < 0.001 |
| Height, cm | 155.1 ± 13.9 | 149 ± 15.1 | < 0.001 | 154.3 ± 14.3 | 151.9 ± 14.1 | 0.256 |
| Weight, kg | 44.6 ± 13.4 | 36.8 ± 11.2 | < 0.001 | 43.6 ± 13.4 | 39.3 ± 12.2 | 0.031 |
| Waist circumference, cm | 69.6 ± 10.4 | 64.6 ± 9.6 | < 0.001 | 68.8 ± 10.4 | 61.4 ± 10.8 | 0.37 |
| Hip circumference, cm | 82.8 ± 10.6 | 76.7 ± 8.7 | < 0.001 | 81.9 ± 10.7 | 80 ± 9.8 | 0.22 |
| Vitamin D, ng/mL | 15.2 ± 5.5 | 15.3 ± 5.5 | 0.883 | 15.1 ± 5.5 | 16.1 ± 5.4 | 0.23 |
| Calcium, mg/dL | 9.8 ± 0.5 | 9.9 ± 0.5 | 0.82 | 9.8 ± 0.5 | 9.9 ± 0.5 | 0.23 |
| Phosphorus, mg/dL | 4.04 ± 0.77 | 4.16 ± 0.54 | 0.16 | 4.1 ± 0.7 | 4.1 ± 0.5 | 0.79 |
| Fat mass index, kg/m 2 | 4.4 ± 3.10 | 3.1 ± 1.3 | 0.01 | 4.3 ± 3 | 3.7 ± 1.5 | 0.4 |
| Lean mass index, kg/m 2 | 14.6 ± 11.4 | 12.9 ± 2.1 | 0.31 | 14.5 ± 11 | 13 ± 2.3 | 0.5 |
| Sun exposure, % | ||||||
| low | 44.3 | 49.4 | 0.178 | 44.3 | 53.2 | 0.327 |
| medium | 39.4 | 40.5 | 39.3 | 42.6 | ||
| high | 16.2 | 10.1 | 6.4 | 4.3 | ||
| Physical activity, % | ||||||
| insufficient | 66.5 | 79.8 | 0.015 | 66.7 | 88.2 | 0.02 |
| sufficient | 33.5 | 20.2 | 33.3 | 11.8 | ||
| Puberty, % | ||||||
| Prepubertal | 33 | 44 | 0.041 | 31.5. | 39 | 0.067 |
| Earlypubertal | 35 | 29.9 | 37.5 | 34.9 | ||
| Late pubertal | 32 | 25.8 | 31 | 25.8 | ||