Table 1.
Subject Characteristics
| |
Males |
Females |
Two-Way ANOVA |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Variable1 | N | Overall | White | Black | White | Black | S x R | Sex (S) | Race (R) |
| Age (years) | 323 | 11.3 ± 1.2 | 12.3 ± 0.9 | 11.6 ± 1.1 | 10.9 ± 1.0 | 10.7 ± 1.0 | NS4 | <0.001 | <0.001 |
| Whole Body Composition | |||||||||
| Weight (kg) | 323 | 47.4 ± 12.2 | 45.4 ± 11.0 | 45.5 ± 12.0 | 43.3 ± 8.4 | 46.8 ± 10.4 | NS | NS | 0.014 |
| Height (cm) | 323 | 151 ± 9 | 153 ± 8 | 150 ± 9 | 149 ± 9 | 148 ± 8 | NS | 0.022 | NS |
| BMI-For-Age (%) | 323 | 68.0 ± 29.2 | 51.6 ± 30.7 | 64.2 ± 28.8 | 66.4 ± 26.3 | 75.0 ± 28.3 | NS | 0.002 | 0.009 |
| Fat Mass (kg)2 | 317 | 14.5 ± 6.9 | 12.2 ± 7.0 | 12.3 ± 7.8 | 14.6 ± 5.2 | 16.7 ± 6.2 | NS | <0.001 | NS |
| Percent Body Fat2 | 319 | 29.8 ± 9.4 | 27.6 ± 9.2 | 24.9 ± 9.6 | 32.7 ± 7.4 | 32.4 ± 7.8 | NS | <0.001 | NS |
| Fat-Free Soft Tissue (kg)2 | 315 | 30.0 ± 6.2 | 31.1 ± 5.6 | 29.9 ± 6.0 | 27.8 ± 5.2 | 28.3 ± 5.6 | NS | 0.002 | NS |
| Muscle Composition | |||||||||
| Forearm MCSA (cm2)3 | 319 | 21.2 ± 4.7 | 20.8 ± 3.8 | 22.4 ± 3.9 | 17.9 ± 3.5 | 21.2 ± 3.4 | NS | <0.001 | <0.001 |
| Forearm MD (mg/cm3)3 | 321 | 74.6 ± 13.7 | 81.8 ± 11.5 | 71.0 ± 12.7 | 76.8 ± 8.0 | 67.5 ± 14.1 | NS | 0.012 | <0.001 |
| Forearm IMAT (cm2)3 | 289 | 2.6 ± 1.3 | 2.0 ± 0.9 | 3.3 ± 1.2 | 1.7 ± 0.8 | 2.9 ± 1.1 | NS | 0.043 | <0.001 |
| Calf MCSA (cm2)3 | 315 | 47.9 ± 9.8 | 48.3 ± 9.1 | 46.8 ± 9.0 | 46.5 ± 8.6 | 46.1 ± 9.4 | NS | NS | NS |
| Calf MD (mg/cm3)3 | 318 | 73.3 ± 3.2 | 74.8 ± 2.2 | 72.4 ± 3.2 | 74.4 ± 1.8 | 71.5 ± 2.7 | NS | NS | <0.001 |
| Calf IMAT (cm2)3 | 296 | 10.3 ±3.6 | 9.5 ±3.2 | 11.0 ± 3.1 | 9.2 ±3.1 | 11.0 ± 3.9 | NS | NS | 0.001 |
| Handgrip Strength (kg) | 288 | 18.0 ± 9.5 | 16.3 ± 8.5 | 22.8 ± 7.2 | 15.1 ± 7.9 | 20.6 ± 8.7 | NS | NS | <0.001 |
| Dietary Intake | |||||||||
| Energy (kcal) | 307 | 2001 ± 556 | 2092 ± 519 | 2035 ± 646 | 2010 ± 530 | 1885 ± 477 | NS | NS | NS |
| Calcium (mg) | 307 | 901 ± 395 | 938 ± 420 | 801 ± 403 | 993 ± 444 | 860 ± 290 | NS | NS | 0.013 |
| Vitamin D (IU) | 300 | 173 ± 123 | 191 ± 77 | 148 ± 81 | 152 ± 99 | 167 ± 100 | NS | NS | NS |
| Physical Activity iMETs/d) | 304 | 62.2 ± 10.0 | 63.0 ± 9.1 | 60.1 ± 8.6 | 64.7 ± 11.0 | 58.2 ± 8.0 | NS | NS | <0.001 |
| Biochemical Variables | |||||||||
| 25(OH)D (nmol/L) | 318 | 69.9 ± 18.5 | 79.8 ± 13.0 | 62.0 ± 15.2 | 80.5 ± 16.1 | 58.9 ± 18.2 | NS | NS | <0.001 |
| iPTH (pg/mL) | 314 | 26.9 ± 9.9 | 23.8 ± 8.8 | 28.2 ± 9.6 | 25.6 ± 8.4 | 30.0 ± 8.1 | NS | NS | <0.001 |
| l,25(OH)2D (pg/mL) | 318 | 55.4 ± 16.5 | 48.4 ± 15.3 | 54.2 ± 16.6 | 55.3 ± 14.6 | 59.7 ± 14.8 | NS | 0.004 | 0.019 |
1.
Values are Mean ± SD. White (n=159) and black (n=165), males (n=162) and females (n=162)
2.
Measured by dual-energy X-ray absorptiometry
3.
Measured by peripheral quantitative computed tomography; MCSA, muscle cross-sectional area; MD, muscle density; IMAT, intermuscular adipose tissue
4.
NS, Non-significant (p-value > 0.05); Statistically significant if p-value ≤ 0.05 and in bold font