TABLE 1.
Demographic, lifestyle, growth, and body composition characteristics of the Bone Mineral Density in Childhood Study cohort for all study visits
| Variable | |
|---|---|
| Study design | |
| Sample size | 2011 |
| Observations Visits per person | 9846 |
| 1 or 2 visits | 292 (15%) |
| 3 to 6 visits | 929 (26%) |
| 7 visits | 790 (39%) |
| Demographic and lifestyle | |
| Age, y | 13.6 ± 4.2 |
| Female sex observations | 5021 (51%) |
| Race and ethnicity groups | |
| American Indian/Alaskan Native | 13 (0.1%) |
| Asian/Pacific Islander | 694 (7%) |
| Black | 2175 (22%) |
| Hispanic | 1653 (17%) |
| White | 4737 (48%) |
| Other/Unknown | 11 (0.1%) |
| Mixed | 563 (6%) |
| Dietary calcium, mg1 | 849 ± 533 |
| Physical activity, h/wk2 | 14.2 ± 10.8 |
| Growth, maturation, and obesity status | |
| Height, cm | 154.5 ± 18.7 |
| Height Z-score | 0.15 ± 0.85 |
| Weight, kg | 50.67 ± 18.29 |
| Weight Z-score | 0.35 ± 0.83 |
| BMI, kg/m2 | 20.4 ± 3.9 |
| BMI Z-score | 0.31 ± 0.87 |
| BMI category observations | |
| Healthy weight (BMI <85th percentile) | 7719 (78%) |
| Overweight (BMI 85th to 94th percentile) | 1553 (16%) |
| Obese (BMI ≥95th percentile) | 574 (6%) |
| Tanner stage observations3 | |
| Stage 1 | 2408 (27%) |
| Stage 2 to 4 | 2532 (27%) |
| Stage 5 | 4133 (46%) |
| Body composition | |
| Appendicular lean soft tissue mass index, kg/m2 | 6.6 ± 1.5 |
| Fat mass index, kg/m2, mean ± SD | 4.9 ± 2.3 |
| Lean soft tissue mass index, kg/m2 | 14.9 ± 2.7 |
| Total lean body mass, kg | 37.2 ± 13.9 |
| Subtotal lean body mass, kg | 34.1 ± 13.5 |
| Total fat mass, kg | 12.0 ± 6.6 |
Values are mean ± SD or n (%).
1
n = 9837
2
n = 9843
3
Tanner stage available for n = 9073